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ISSN 0003 1216
J O U R N A L
OF THE
AMERICAN SOCIETY
OF
SUGAR BEET T E C H N O L O G I S T S
VOL. 20, No. 3 JULY 1979
EXECUTIVE COMMITTEE
President M A . Woods Union Sugar Division
Santa Maria. California
Vi<e President Stewart Bass American Crystal Sugar Co,
Moorhead. Minnesota
Secretary Treasurer James H. Fischer Beet Sugar Development Foundation
Fort Collins. Colorado
Immediate Past President Glen W. Yeager I lolly Sugar Corporation
Colorado Springs. Colorado
BOARD OF DIRECTORS
Pacific Coast Region: John M. Kendrick
Intermountain Region: A. Kent Xielson
F.astern Rockv Mountain
Region: D. D. Dickenson
North Central Region: E.L..Swift
Great Lakes Region: Richard Zielke
Canadia: John W. Hall
Processing at Large: Stanley F. Bichsel
Agriculture at Large: John T. Alexander
ISSN 0003-1216
J O U R N A L
of the
American Society of Sugar
Beet Technologists
Volume 20 Number 3 July 1979
American Society of Sugar Beet Technologists
Office of the Secretary
P.O. Box 1546
Fort Collins. Colorado 80522
Made in the United States ot America
TABLE OF CONTENTS
Title Author Page
A study of sugar drying and conditioning. .. Souly Farag 207
Residual soil nitrogen and phosphorus in D. G. Westfall some sugarbeet fields W. J. Eitzman in Montana and Wyo- D. R. Rademacher ming R. G. Vergara 217
Bibliography: methods of sucrose analysis. . . .Douglas W. Lowman 233
Separation and analysis of some sugars by using thin layer chromatography Souly Farag 251
Effect of chemicals on sucrose in sugar- W. R. Akeson beets during stor- Y. M. Yun age E. F. Sullivan 255
Effect of injury on respiration rates R. E. Wyse of sugarbeet roots C. L. Peterson 269
Remedying inadequate crystallizer capacity R. A. McGinnis 281
The effect of soil residues of atra- R. L. Zimdahl zine on sugarbeets s. M. Gwynn (Beta vulgaris L . ) . . . . K. Z. Haufler 297
The effect of root dehydration on the storage performance of a sugarbeet genotype resistant to W. M. Bugbee storage rot D. F. Cole 307
A Study of Sugar Drying and Conditioning
SOULY FARAG
Received for publication August 15, 1977
ABSTRACT
A laboratory investigation of the mechanism of sugar dry
ing was conducted. The effects of drying time, air temper
ature, and agglomerates on drying rate and the final mois
ture content of sugar crystals were examined. Because of
the complicated nature of this study on a factory scale,
a bench model granulator was constructed.
The study indicated that the drying temperature has consid
erable effect on the quality of the finished product. High
temperature drying tends to encourage the formation of
small sugar particles which can in part contribute to the
dust problem.
INTRODUCTION
In the sugar industry, it is necessary to store a signifi
cant portion of the production for a considerable length of
time. Caking and dust formation are usually encountered
during sugar handling and storage. The final product
should, however, reach the consumer in first class condi-(2)
tion. Krautmann claimed that most of the unfavorable
phenomena such as caking and dust formation result from
the supersaturated film on the crystal surface and are
caused by conditions encountered during the drying process.
Powers (4) indicated that the major cause of dust formation
is the rapid drying of the thin films of syrup left on
sugar after spinning. Accordingly, drying in the granu
lator may be considered as a continuation of the crystal
lization process. Others demonstrated that wet sugar
*Sr. Research Chemist, U & I, Incorporated, Moses Lake, Washington 9 8 837.
208 JOURNAL OF THE A.S.S.B.T.
samples washed with alcohol prior to drying dried with a
brilliant shine, a negligible amount of dust, and very
little tendency toward caking.
This investigation was undertaken in order to determine the
effects of various drying conditions on the physical char
acteristics of sugar crystals.
MATERIALS AND METHODS
Equipment: A bench batch dryer (granulator) with an approx-
imate capacity of 12 quarts per hour was constructed at our
laboratory. It consisted of a cylinder 18" long and 12"
in diameter, with eight evenly spaced flights inside to
give a more efficient agitation of the sugar. The granu
lator was supplied with a small fan and heating unit to
provide a stream of forced hot air, and was rotated at a
constant speed of ten revolutions per minute. The granu
lator was capable of drying a two liter sample of sugar to
.05% moisture content in approximately the same time as
that required by the factory granulators.
A conditioning bin model was also constructed. It con
sisted of an 18" long by 5" diameter glass chromatogranh
tube with a fritted glass disc in the bottom. Air was
blown up through the disc and distributed through a layer
of sugar placed over it. The air supply was laboratory
compressed air that had passed through a silica gel dryer
and a rotameter to measure the volume of air used.
Moisture was determined on the samples by a standard method
for the determination of moisture in sugar. Samples were
dried in glass-stoppered weighing bottles for a period of
three hours in a 105°C oven, then cooled and reweighed to
determine weight loss. Dust levels were determined by us
ing the method developed at the U and I Research Labora-
tory. ( 1 )
Procedure: A two-liter sample of wet sugar was found to be
VOL. 20 NO. 3 JULY 1979 209 the optimum amount for the operation of the bench granula-
tor. Prior to drying a sample, the granulator was preheat
ed to the desired temperature for a period of 10 to 15
minutes, then the sample of wet sugar was added. Drying
temperatures were varied from 25° to 145°C. The granulator
was started with samples collected at pre-determined inter-
vals in bottles which were stoppered and allowed to cool.
Approximately 10 grams of the sample was taken, quickly
and accurately weighed, then dried in an oven for three
hours at 105°C.
The sample was then cooled in a dessicator, reweighed, and
the percent moisture calculated. The dried sugar was con
ditioned and examined under the microscope. Finally, the
sample was tumbled in a plastic bottle for 30 minutes in
order to simulate the effect of physical movement, and
dust levels determined.
Further tests were conducted in order to examine the drying
pattern of sugar crystals as compared to the drying char
acteristics of both wet sand and sodium chloride, and
additional tests compared the drying rate of conglomerate
sugar to that of clean, uniform grain.
RESULTS AND DISCUSSION
The average results for varying air temperatures (25, 70,
100 and 145°C) are illustrated in Figure 1. It should be
noted that in all cases the initial moisture content was
considered to be unity, and all moisture contents were
adjusted accordingly.
From these curves, it can be seen that sugar drying is not
a smooth, continuous process. Each curve can be divided
into a warming up period followed by a constant rate period
which appears on the graph as a straight line. The third
period of drying is typified by a continuously changing
rate until the entire surface is supersaturated. This marks
the start of a portion of the drying cycle in which the rate
210 J O U R N A L OF T H E A.S.S.B.T.
Figure 1. Sugar drying at various temperatures.
of internal moisture movement and crystallization from the
syrup controls the drying rate. (3)
Figure 2. Air temperature versus drying time (constant time curves) - Moisture indicated as percent.
VOL. 20 NO. S JULY 1979 211 Figure 2 shows the length of time required to reach percent
moistures from 0.8 to 0.04 at various air temperatures.
Note, for example, that with air at 140°C, it takes 1.25
minutes to dry sugar to 0.06% moisture. If the same sugar
were dried with air at 100°C, it requires only two minutes.
A drop of 40°C in air temperature lengthens the drying time
to the .06% moisture level by only three-quarters of a
minute. On the other hand, there is a much larger differ
ence in the time required to reduce the moisture level from
.06 to .04% at temperatures below 100°C. At these moisture
levels, the low temperatures do not appear to provide the
driving force required to force the moisture out of the
saturated sugar solution surrounding the crystals.
Figure 3. Air temperature versus % moisture (constant time curves) - Time indicated in seconds.
Figure 3 includes constant-time curves which illustrate
the relationship of moisture to temperature; both high tem
perature and long drying time are required in order to
effect moisture reduction below the 0.1 level.
Figure 4 includes the drying curves for equal volumes of
sugar, sand, and sodium chloride dried at 100°C. In the
case of drying sand, the phenomenon illustrated is merely
212 JOURNAL OFTHE A.S.S.B.T.
Figure 4. Comparison between drying curves, Sugar-sand-salt.
the evaporation of water from the surface. In the case of
sugar, the wet sugar loses moisture first by evaporation
from a syrup film on the surface of the crystal down to
a moisture content of approximately .05%, followed in turn
by a period of evaporation of a supersaturated surface which
is gradually increasing in saturation until such a point
that crystallization starts to take place. It is at this
point that, in theory, the dust is formed. Sodium chloride
is similar to sugar in that it is a soluble solid. It
does not, however, form an appreciable glaze or surface
layer upon drying as sugar does. This layer seems to
cause an increase in the drying time of sugar crystals.
It should be pointed out that both sand and sodium chloride
have higher specific gravity and higher specific heat than
sugar.
Sample 1 was a strike of sugar that had a large percentage
of conglomerates, while Sample 2 had a very clean, uniform
grain. As can be seen from the table, Sample 1 had a
higher initial moisture content than did Sample 2. - the
latter had half the moisture content of Sample 1 after
they both had been dried for a 10-minute period. This
is due almost entirely to the fact that a conglomerate
sugar has more syrup trapped on the surface, than does a
well formed crystal. On a number of samples tested, there
was a large variation in the moisture content of the sugar
being introduced to the granulator. It has been shown
that the initial moisture content has a very important
bearing on the efficiency of the granulator operation,
A further study of dust formation at various air tempera
tures was as follows:
Wet sugar samples were taken from the spinners, then dried
for ten minutes in the laboratory bench granulator at
70, 100, and 145°C, respectively. The samples were further
treated for four hours in a conditioning bin model using
dry air in an attempt to remove all moisture present in
sugar in excess of the equilibrium quantity. Samples were
214 JOURNAL OF THE A.S.S.B.T.
then tumbled in plastic bottles for 30 minutes. Percen-
tages of dust were determined at 0.043, 0.058, and 0.083,
respectively.
Microscopic examination of different samples indicated that
crystals dried at higher temperature (145°C) were clear and
sparkling as they came from the granulator. After condi-
tioning, the sugar became dull and the slightest movement
could produce very fine dust. On the other hand, sugar
dried at lower temperature does not change appreciably
in appearance after it has been conditioned. In general,
there was a tendency for sugars dried at higher tempera-
ture to form dust more readily than sugars dried at lower
temperatures. Figures 5 and 6 illustrate the effect of dry-
Figure 5. Sugar sample Figure 6. Sugar sample dried at 100°C. dried at 145°C.
ing temperature on dust formation. It can be seen that
the coating surrounding the crystals dried at 145°C looks
almost amorphous. The submicroscopic crystals covering
the mother crystal can be seen easily through the micro-
scope at a high magnification (325x). It should be point-
ed out, however, that samples dried at high temperature
(120-145°C) had less caking and required longer time for
setting-up to take place.
VOL. 20 NO. 3 JULY 1979 215
Figure 7. Sugar crystal dried at 145°C at 325x.
It is important to emphasize that the drying rate and the
final moisture content of sugar are also influenced by other
factors besides time, temperature, and conglomeration.
These factors include particle size, initial moisture con-
tent, and the humidity of the surrounding air.
CONCLUSION
This study indicates that the drying temperature has con-
siderable effect on the nature of the finished sugar. High
temperature drying tends to encourage the formation of
small sugar particles loosely bound to the surface of the
sugar crystal, giving it a dull, opaque appearance. Dur-
ing handling these particles are rubbed off quite easily
and contribute at least in part to the dust problem.
Furthermore, any means of producing a wet sugar product
at a reduced and uniform moisture content would be of great
advantage. In this light, it can be seen that the centri-
fugals act as separators and physically remove the moisture.
This is a relatively simple process which requires a rela-
tively small amount of energy. On the other hand, granu-
lators remove the water by a phase change or evaporation
216 J O U R N A L OF T H E A.S.S.B.T.
Which, from an engineering standpoint, requires a much
greater amount of energy.
LITERATURE CITED
(1) Farag, S. A., L. W. Norman, and C. L. Schmalz. 1971. Some physical characteristics of sugar crystals affecting dust formation. Sugar Beet Technol. 16: 448-456.
(2) Krautmann, Hans. 19 60. Preparing refined sugar for silo storage. Sugay y Azucar 55: 50-51.
(3) Perry, John H. 1963. Chemical Engineer's Hand-book, pp. 15-35.
(4) Powers, H.E.C. 1960. Sugar Crystallization in thin films. International Sugar Journal 62: 307-312.
Residual Soil Nitrogen and Phosphorus in some Sugarbeet Fields in Montana and Wyoming
D. G. WESTFALL, W. J. EITZMAN,
D. R . R A D E M A C H E R A N D R. G . V E R G A R A *
Received for publication December 5, 1977
INTRODUCTION
Proper management of soil fertility in sugarbeet (Beta vul-
garis L.) production is of economic importance, particular-
ly with nitrogen (N) where the proper control of N availa
bility is a critical compromise between supplying enough
to produce optimum yields and yet limiting availability to
produce sugarbeets of high sugar content and purity (1, 3,
4, 5, 7, 8, 9, 10, 11, 12, 13, 15, 20, 25, 28, 29, 30).
Nitrogen fertility requirement can best be determined with
deep soil sampling and analysis of these samples for re-
sidual NO -N (8, 15, 16, 18, 24, 25). Consequently, the
importance of a deep soil sampling program to the economics
of sugarbeet production is indisputable.
Phosphorus (P) is the second most important fertilizer nut-
rient that is needed for sugarbeet production. Growers
and soil scientists recognize that soil testing is the only
reliable method to determine P fertilizer requirements.
Several investigators (4, 22, 26) have summarized the re-
search results on P requirements of sugarbeets. A detri-
mental effect on sugarbeet yield from applying P fertilizer
to soils that test high in residual P has been suggested
(6, 14), although conclusive evidence has not been reported.
*The authors are respectively Senior Plant Nutritionist, Great Western Sugar Co., Agricultural Research Center, Longmont, CO 80501; Former Manager, Agricultural Research, Montana-Wyoming (Presently Agriculturalist, Billings, M T ) ; Manager, Agricultural Research, Oregon; and Agriculturalist, Lovell, Wyoming. The senior author is presently an Associate Professor, Department of Agronomy, Colorado State University, Fort Collins, Colorado 80523.
218 JOURNAL OF THE A.S.S.B.T.
Our results from a number P rate experiments, however, have
nόt evealed a detrimental effect of excessive P fertility
rates on sugarbeet yield or quality.
It has been suggested by Skogley (27) that sugarbeets may
require potassium (K) fertilizer on some soils in Montana.
This opinion is not shared by the authors. Secondary and
micronutrient difficiencies are not known to exist in sug-
arbeets in the area studied; consequently, the only fer-
tilizer nutrients required for maximum sugar production
are N and P.
Several hundred fields have been soil sampled since 1974
in the Great Western Sugar Co. factory districts of Bil-
lings, Montana and Lovell, Wyoming for fertilizer recom-
mendations for sugarbeet growers. This is the first ex-
tensive deep soil sampling data to be collected in these
two areas. The results are summarized in this publication
with the following objectives: 1) to identify the residual
soil N and P levels that commonly occur; 2) to determine
the residual soil N profile distribution; and 3) to evalu-
ate the effect of previous cropping history on residual soil
N and P leveIs.
MATERIALS AND METHODS
Soil samples were collected at 1-foot increments to a depth
of 3 feet in the Lovell, Wyoming district (Big Horn Basin)
and to a depth of 3-6 feet in the Billins, Montana district
(Middle Yellowstone River Valley). A gravel layer at ap-
proximately 3 feet in the Big Horn Basin restricts sampl-
ing and limits root development below this depth. All data
from Montana were adjusted to a 4-foot depth since this is
the maximum recommended sampling depth (2) and is generally
considered to be the effective rooting depth of sugarbeets
in these soils. The following number of fields were sampled
in the preceeding fall or spring for the various crop years:
Wyoming, 1974 - 56 fields and 1975 - 185 fields, total - 241
VOL. 20 NO. 3 JULY 1979 219
f i e l d s ; M o n t a n a , 1974 - 36 f i e l d s , 1975 - 84 f i e l d s , 1976
- 5 1 fields and 1977 - 135 f i e l d s , total - 306 f i e l d s .
The 0-1 foot s a m p l e was a n a l y z e d for a v a i l a b l e P w i t h the
s o d i u m b i c a r b o n a t e m e t h o d (21) and organic m a t t e r (O.M.)
by the wet — o x i d a t i o n m e t h o d . All foot i n c r e m e n t s w e r e an-
alyzed for N0 3 - N u s i n g the O r i o n s p e c i f i c ion e l e c t r o d e
s y s t e m by the f o l l o w i n g p r o c e d u r e : A 50 g soil s a m p l e w a s
e x t r a c t e d with 180 m l d i s t i l l e d w a t e r ; the s u p e r n a t e w a s
c e n t r i f u g e d and d e c a n t e d after w h i c h 0.1m s o d i u m c i t r a t e
was added (1:9 c i t r a t e to e x t r a c t ratio) to e l i m i n a t e e l e c
trode i n t e r f e r e n c e s due to v a r y i n g ionic s t r e n g t h s b e t w e e n
e x t r a c t s ( 2 3 ) . The r e s u l t s are r e p o r t e d in lb N03 - N / A .
R E S U L T S AND D I S C U S S I O N
R e s i d u a l N i t r a t e — N i t r o g e n
The r e s i d u a l NO -N l e v e l s in M o n t a n a and W y o m i n g in 25 l b / A
i n c r e m e n t s are s h o w n in F i g u r e s 1 and 2. In M o n t a n a , the
m a j o r i t y of the fields had r e s i d u a l N 0 3 - N l e v e l s r a n g i n g
from 2 6 - 5 0 (30%) and 5 1 - 7 5 lb/A (31%) with less than 1%
h a v i n g r e s i d u a l l e v e l s less than 26 lb/A. A d i f f e r e n t dis-
t r i b u t i o n p a t t e r n o c c u r r e d in W y o m i n g . The m a j o r i t y of the
f i e l d s had r e s i d u a l NO -N l e v e l s r a n g i n g from 0-25 (30%)
and 2 6 - 5 0 lb/A ( 4 2 % ) . The 0-25 lb/A of r e s i d u a l N 0 3 - N
range of 3 0 % o c c u r r e n c e in W y o m i n g is c o n t r a s t e d to less
than a 1% o c c u r r e n c e in M o n t a n a . T w e n t y - o n e p e r c e n t of
the fields in M o n t a n a had r e s i d u a l N0 3 - N levels a b o v e 100
lb/A w h i l e in W y o m i n g only 8% of the fields e x c e e d e d this
l e v e l . L u d w i c k , S a l t a n p o u r , and Reuss (19) r e p o r t e d the
d i s t r i b u t i o n of r e s i d u a l N O 3 - N levels of soil s a m p l e s test-
ed by the C o l o r a d o State U n i v e r s i t y Soil T e s t i n g L a b o r a t o r y .
T h e s e f i g u r e s p e r t a i n e d to the e n t i r e state and not spe-
c i f i c a l l y to s u g a r b e e t f i e l d s a l t h o u g h the vast m a j o r i t y
of s a m p l e s u n d o u b t e d l y came from a r e a s w h e r e s u g a r b e e t s
are g r o w n in r o t a t i o n with other c r o p s . They r e p o r t e d that
5 0 % of the C o l o r a d o f i e l d s c o n t a i n e d less than 3.6 lbs N / A
and 2 2 % c o n t a i n e d from 36 to 72 lbs N/A. The d i s t r i b u t i o n
p a t t e r n in M o n t a n a soils is q u i t e d i f f e r e n t in that less
220 JOURNAL OF THE A.S.S.B.T.
RESIDUAL N O 3 - N ( lbs . A )
Figure 2. The residual soil NO3 -N levels of sugarbeet fields in Wyoming.
VOL. 20 NO. 3 JULY 1979 221
than 1% of the fields contained less than 25 lb N/A. The
Wyoming patterns are more similar to those reported for
Colorado.
The differences in residual N0--N levels in Montana and
Wyoming are expected because the soils of the Big Horn Ba-
sin in Wyoming are generally light textured, shallow soils
that are subject to leaching if excessive irrigation water
is applied. The annual precipitation is approximately 7
inches; consequently, this does not result in leaching.
In the Middle Yellowstone River Valley of Montana, the
soils are generally heavier textured and deeper. Annual
precipitation is about 14 inches. In general, little NO3-N
leaching from rainfall is expected. The exception to this
may be after heavy down pours or during snow melt when
water accumulates in low areas of fields.
The average distribution patterns of the residual N03-N
within the profiles of the two areas of study are shown in
Figures 3 and 4 . In Montana, 38% of the NO -N was present
in the surface foot with 23%, 20% and 19% in the second,
third and fourth foot increments, respectively. In the
shallower soil profiles of Wyoming, the decrease in resid-
ual NO3-N with depth is very rapid. About 62% of the re-
sidual NO3-N was found in the surface foot with 22% and
18% occurring in the second and third foot increment, re-
spectively. In some Colorado soils, Reuss and Rao (24)
reported that 60% of the residual N03-N was present in the
surface foot of their 4-foot profile. In a second study
Ludwick, Reuss, and Giles (18) found about 50% of the re-
sidual N O - N occurred in the surface foot. The level of
N O - N in the surface foot in the average Montana soil pro-
file is considerably less than that reported by the Colo-
rado researchers.
The wide variation in residual N03-N levels in fields in
the areas studied clearly points out that an "average"
fertilizer reco mm endation can not be made with the expecta-
222 JOURNAL OFTHE A.S.S.B.T. DISTRIBUTION OF RESIDUAL
Figure 3. The average profile distribution of residual NO3-N in sugarbeet fields in Montana.
F i g u r e 4 . The average profile distribution of residual NO3 -N in sugarbeet fields in Wyoming.
VOL. 20 NO. 3 JULY 1979 223
tion of achieving the optimum compromise between yield and
quality. An optimum rate can be achieved only through soil
testing of each field and tailoring the N recommendation to
take into account the specific residual N03-N level present
in that field .
Organic Matter
The distribution of O.M. content of the fields in the two
areas are presented in Figures 5 and 6 . The most frequent
ly observed O.M. range in both areas was 1.1-1.5% with a
43 and 66% distribution in Montana and Wyoming, respective
ly. The range of O.M. content in Wyoming is narrower than
in Montana; only 20% of the Wyoming fields had less than
1% O.M. and only 1% had greater than 2.0% O.M. These dis
tributions are contrasted to 27% less than 1.0% O.M. and
7% greater than 2.0% O.M. in Montana.
Residual Phosphorus
The P distributions are shown in Figures 7 and 8. In both
areas about 10% of the fields tested very low in P. Using
the new P fertilizer recommendations of the Great Western
Sugar Co. and Colorado State University, the fertilizer
recommendation would be 100 lb P205/A for a "very low" P
test level. Forty-four and 32% of the fields tested "low"
in P with a 50 lb P 0 /A fertilizer recommendation and 29
and 36% tested "medium" with a 30 lb P205 /A recommendation
for Montana and Wyoming, respectively. Soil test levels
above 23 ppm P do not need P fertilization; in Montana this
constituted 17% of the fields and Wyoming 24%. Most fields
received P fertilizer each year and excessive P fertilizer
rates are probably applied in these areas as is the situa
tion in the rest of the G. W. production area. Neverthe
less, many of the fields do need P fertilizer. The wide
range in percent P distribution of fields from these two
areas further points to the need for soil testing. This is
the only reliable method of determining the proper amount
of P fertilizer to apply.
i
224 JOURNAL OFTHE A.S.S.B.T.
F i g u r e 5. The soil o r g a n i c m a t t e r c o n t e n t of s u g a r b e e t fields in M o n t a n a .
F i g u r e 6. The soil o r g a n i c m a t t e r c o n t e n t of s u g a r b e e t fields in W y o m i n g .
VOL. 20 NO. 3 JULY 1979 225
RESIDUAL P0 4 - P (ppm )
F i g u r e 7. The r e s i d u a l soil P O 4 - P levels of s u g a r b e e t f i e l d s in M o n t a n a .
F i g u r e 8. The r e s i d u a l soil P O 4 - P l e v e l s of s u g a r b e e t fields in W y o m i n g .
226 JOURNAL OF THE A.S.S.B.T. Previous Cropping History
The previous cropping history had an appreciable influence
on the residual and P levels found in fields in Wyo-
ming but not in Montana (Table 1 ) . In Wyoming, when the
previous crop was sugarbeets, the average residual soil
N O - N level was very low (25 lb/A) and the P level was in
the "medium" soil test range (18.2 ppm). The highest
level was found when the previous crop was malting barley.
The soil test P level was also in the "medium" range. Pre
vious crops of beans, small grains, and corn had N O - N lev
els ranging from 4 5 to 6 6 lb/A and P levels of 12.1 to 14.7
ppm. In Montana, the and P levels were very narrow
and were not appreciably different. The reason for the dif
ferences in residual NO3-N levels in Wyoming may possibly
be attributed to mineralization that occurs between crop
removal and sampling as well as fertilizer carry over.
Corn, malting barley and small grains are harvested several
weeks earlier than sugarbeets. This may result in an ac
cumulation of from mineralization while, no crop is
growning on the soil.
Table 1. Relationship between previous crop and residual N O 3 N and PO -P levels in fields to be planted to sugarbeets (1975).
Previous Crop
Sugarbeets
Beans
Sma11 Grains
Corn
Malting Barley
VOL. 20 NO. 3 JULY 1979 227 Soil Test Variations Between Areas
To further identify the fertility relationships in these
two regions, the soil test information from various geo
graphic areas was summarized. The areas were determined by
the proximity to receiving stations in what is considered
to be "similar production areas." The residual P levels
in Montana ranged from 11.5 ppm in the Pompeys Pillar-Worden
area to 22.8 ppm in Laurel-Park City area (Table 2 ) . The
Wyoming range was much narrower: a low of 12.9 ppm in Deaver
to a high of 19.4 ppm in the Willwood area. The average
residual P level in Wyoming is higher than in Montana. The
reason for this is not fully understood since Montana soils
are heavier textured and higher in O.M. This difference is
likely due to different fertility practices in the two areas
but could also be related to geologic factors.
The 0. M. content ranged very little in both Montana and
Wyoming with the exception of the Hysham area. The O.M.
content of this area averaged 2.86%; 1.25% higher than any
other area.
The average residual NO -N level in Montana was about twice
as high as in Wyoming. Previous work (D. G. Westfall, un
published) has shown that there is a very high correlation
between residual NO3-N levels in the spring and sugar con
tent at harvest. The Lovell factory generally has the high
est company average sugar content which could be expected
comparing residual NO3-N values between areas. The resid
ual NO -N (and total N) level in Laurel-Park City area ave
raged 113 lb/A, highest for Montana areas; the Hardin area
was lowest (63 lb/A). It is interesting to note that the
Laurel-Park City area also had the highest P level. These
high levels indicate that growers in this area are using
higher N and P fertilizer rates than in other areas. This
practice would not be limited to sugarbeets, but also ap-
plied to other crops in the rotation. The residual NO3-N
variation between areas was much smaller in Wyoming, with
the maximum being 54 lb/A and the minimum 33 lb/A. The
Table 2. The phosphorus, organic matter and residual nitrogen levels of sugarbeet fields in various production areas of Montana and Wyoming.
VOL. 20 NO. 3 JULY 1979 229
e x i s t e n c e of a g r a v e l layer in the p r o f i l e at a b o u t three
feet and the o c c u r r e n c e of l e a c h i n g d u r i n g i r r i g a t i o n is
thought to be the r e a s o n for the lower a v e r a g e l e v e l of
r e s i d u a l N 0 3 - N as w e l l as the r e l a t i v e u n i f o r m i t y b e t w e e n
a r e a s .
S U M M A R Y
The r e s i d u a l N O 3 - N , P, and O.M. c o n t e n t s of f i e l d s to be
p l a n t e d to s u g a r b e e t s w e r e d e t e r m i n e d in the G r e a t W e s t e r n
Sugar Company's p r o d u c t i o n areas of M o n t a n a and W y o m i n g .
The p e r c e n t o c c u r r e n c e of fields w i t h i n v a r i o u s r a n g e s w a s
d e t e r m i n e d . The r e s u l t s show that a w i d e v a r i a t i o n in
r e s i d u a l NO 3-N and P l e v e l s occur in these p r o d u c t i o n a r e a s .
This p o i n t s out the i m p o r t a n c e of soil testing to d e t e r m i n e
the m o s t e c o n o m i c a l f e r t i l i z e r r e c o m m e n d a t i o n . N o g e n e r a l
f e r t i l i z e r r e c o m m e n d a t i o n can be m a d e . This is e s p e c i a l l y
true i n M o n t a n a w h e r e r e s i d u a l N O 3 - N levels w e r e g e n e r a l l y
h i g h e r and m o r e v a r i a b l e than in W y o m i n g . Based on the
a v e r a g e total r e s i d u a l N a v a i l a b l e in the M o n t a n a s o i l s ,
the a v e r a g e N f e r t i l i z e r r e c o m m e n d a t i o n w o u l d be 87 l b / A .
This w o u l d result in p r o p e r N f e r t i l i z a t i o n of a b o u t 1 8 %
of the f i e l d s , under f e r t i l i z a t i o n of 6 2 % and over f e r
t i l i z a t i o n of 2 0 % . N e e d l e s s to s a y , a v e r a g e s are not a p
p l i c a b l e w h e n m a k i n g a f e r t i l i z e r r e c o m m e n d a t i o n for a
s p e c i f i c f i e l d . Deep soil testing is the only i n t e l l i g e n t
m e t h o d t o d e t e r m i n e a c c u r a t e f e r t i l i z e r r e c o m m e n d a t i o n s
that w i l l i n s u r e o p t i m u m e c o n o m i c r e t u r n .
230 JOURNAL OF THE A.S.S.B.T.
LITERATURE CITED
(1) Adams, S. N. 1962. The response of sugar beet to fertilizer and the effect of farmyard manure. J. Agric. Sci., Camb. 58:219-26.
(2) Anonymous, 1974. Fertilizer Guide, Sugarbeets - Ir-rigated. Montana State University Extension Ser-vice publication AG55.61:60.
(3) Boyd, D. A., P. B. H. Tinker, A. P. Draycott and P. J. Last 1970. Nitrogen requirement of sugar beet grown on mineral soils. J. Agric. Sci., Camb. 74:37-46.
(4) Draycott, A. P. 1972. Sugarbeet nutrition, 250 p. John Wiley & Sons, New York.
(5) Draycott, A. P. and G. W. Cooke 1966. The effect of potassium fertilizer on quality of sugar beet. Potass. Symp. 1966, 131-5.
(6) Draycott, A. P., M. J. Durrant, and D. A. Boyd. 1971. The relationship between soil phosphorus and response by sugarbeet to phosphate fertilizer on mineral soils. J. Agric. Sci., Cam. 77:117-121.
(7) Follett, R. H., W. R. Schmehl, LeRoy Powers, and Merle G. Payne. 1964. Effect of genetic popula-tion and soil fertility level on the chemical composition of sugar beet tops. Colo. Agr. Exp. Sta. Tech. Bull. 79.
(8) Giles, J. F. 1974. Prediction of nitrogen status of sugar beets by soil analysis. PhD Thesis, Colorado State University.
(9) Giles, J. F., J. 0. Reuss, and A. E. Ludwick. 1975. Prediction of nitrogen status of sugarbeets by soil analysis. Agron. J. 67:454-459.
(10) Haddock, Jay L. 1952. The nitrogen requirement of sugar beets. J. Am. Soc. Sugar Beet Techr.:1 . 7 :159-169 .
(11) Haddock, J. L., P. B. Smith, A. R. Downe, J. T. Alexander, B. E. Easton, and Vernal Jensen. 1959. The influence of cultural practice on the quality of sugar beets. Am. Soc. Sugar Beet Technol. 10: 290-301.
(12) Halverson, A. D. and G. P. Hartman. 1975. Long-term nitrogen rates and sources influence sugar-beet yield and quality. Agron. J. 67:389-393.
VOL. 20 NO. 3 JULY 1979 231 (13) Hills, F. J. and Albert Ulrich. 1971. Nitrogen
nutrition. In R. T. Johnson, G. E. Rush, and J. T. Alexander (eds) Sugarbeet production, principles and practices. Iowa State Univ. Press, Ames .
(14) James, D. W. 1972. Soil fertility relationships of sugarbeets in central Washington: Phosphorus, potassium-sodium and chlorine. Tech. Bull. 69, Wash. Agric. Exp. Sta. 21p.
(15) James, D. W. 1971. Soil fertility relationships of sugarbeets in central Washington: Nitrogen. Wash. Agr. Exp. Sta. Tech. Bull. 68. 14p.
(16) James,D. W., A. W. Richards,W, H. Weaver and R. L. Reeder. 1967. Residual soil nitrate measurement as a basis for managing nitrogen fertilizer practices for sugarbeets. J. Am. Soc. Sugar Beet Technol. 16:313-322.
(17) Ludwick, A. E., J. 0. Reuss and J. F. Giles. 1974. Nitrogen fertilizer requirements of sugarbeets predicted by soil analysis. Colo. State Univ. Exp. Sta. PR 74-36 6p.
(18) Ludwick, A. E., J. 0. Reuss and J. F. Giles. 1973. Distribution of soil nitrates in eastern Colorado fields prior to planting sugar-beets. Colo. State Univ. Exp. Sta. PR 73-40 3p.
(19) Ludwick, A. E., P. N. Soltanpour and J. 0. Reuss. 1976. Guide to fertilizer recommendations in Colorado. Colo. State Univ. Cooperative Ext. Service publication. 45p.
(20) McDonnell, P. M., P. A. Gallagher, P. Kearney, and P. Carroll. 1966. Fertilizer use and sugar beet quality in Ireland. Potass. Symp. 1966. 107-26.
(21) Olsen, S. R., C. V. Cole, F. S. Watanabe, and L. A. Dean. 1954. Estimation of available phosphorus in soils by extraction with sodium bicarbonate. USDA Circ. 939.
(22) Peterson, H. B., L. B. Nelson, and J. L. Paschal. 1953. A view of phosphate fertilizer investigations in 15 western states through 1949. USDA Circ . 927 .
(23) Raveh, Ariella. 1972. The adoption of the nitrate-specific electrode for soil and plant analysis. Soil Sci. 116:388-389.
(24) Reuss, J. 0., A. E. Ludwick, and J. F. Giles. 1973. Prediction of nitrogen fertilizer requirements of sugarbeets by soil analysis. Colo. State Univ. Exp. Sta. PR 73-39 4p .
232 JOURNAL OF THE A.S.S.B.T.
(25) Reuss, J. 0. and P. S. C. Rao. 1971. Soil nitrate nitrogen levels as an index of nitrogen fertilizer needs of sugarbeets. J. Am. Soc. Sugar Beet Tech-nol. 16:461-470.
(26) Schmehl, W. R. and D. W. James. 1971. Phosphorus and potassium nutrition. p. 138-169. I_n R. T. Johnson, et al. , eds. Advances in sugarbeet production: principles and practices. The Iowa State Univ. Press, Ames.
(27) Skogley, Earl 0. 1975. Potassium in Montana soils and crop requirements. Montana Exp. Sta. Res. Report 88 . pp. 43-45 .
(28) Stout, Myron. 1961. A new look at some nitrogen relationships affecting the quality of sugarbeets. J. Am. Soc. Sugar Beet Technol. 11:388-398.
(29) Thompson, L. G. 1970. The influence of previous cultural practices on the yield and quality of sugarbeets. MS Thesis, Colorado State University.
(30) Ulrich, Albert. 1961. Plant analysis in sugar beet nutrition. Am. Inst. Biol. Sci. Pub. 8, p. 19 0-211 .
Bibliography: Methods of Sucrose Analysis* DOUGLAS W. LOWMAN
Received for publication March 6, 1978
Numerous methods for the quantitative analysis of sucrose
have been developed. Sucrose concentration may be deter
mined either by direct analysis of the intact sucrose or
by indirect analysis. Using indirect analysis, the sucrose
concentration can be quantitated by determining the concen-
tration of the hydrolysis products of sucrose — D-glucose
and/or D-fructose. In this bibliography, analysis methods
using the techniques of polarimetry, isotope dilution,
nuclear magnetic resonance spectroscopy, chromatography,
colorimetry and spectrophotometry, enzymatic analysis,
enzyme electrodes and titrimetry are summarized. It should
be realized that not every method of sucrose analysis can
be covered here. The coverage has been set at a level to
cover methods of sucrose analysis related to sugar beet
juices, in general, and to demonstrate the broad variation
in the methods available for sucrose quantitative analysis
and some of their problems.
Comparison of the accuracy of each individual method of
sucrose analysis relative to a standard method is not
straight-forward. The International Commission for Uni
form Methods of Sugar Analysis (ICUMSA) has considered
this question and has been unable to arrive at a consis
tent set of conclusions. Accuracies and precisions re
ported here are taken directly from the reference cited.
No attempt is made to relate the accuracy and precision
*Contribution from the Department of Chemistry, Colorado State University, Fort Collins, CO 80523. The author's pre-sent address is: Analytical and Development Services Labor-atory, Organic Chemicals Division, Tennessee Eastman Com-pany, Kingsport, Tennessee 37663.
234 JOURNAL OF THE A.S.S.B.T.
results for each method quantitatively to a standard method
of analysis.
POLARIMETRY (SACCHARIMETRY)
Probably the most widely used method of sucrose analysis
in the sugar industry is polarimetry (39), referred to as
saccharimetry when applied to the measurement of sucrose
content. This method is based on the optical activity of
sucrose. Sucrose may be determined polarimetrically either
with a single polarimetric measurement or with double
polarimetric measurements in conjunction with sucrose
inversion by acid of enzymes.
Sucrose has been determined by a single polarimetric mea-
surement after destruction of reducing sugars (Muller
Method) (38) and in the presence of invert sugar (53).
Heating a sugar solution containing ethylenediamine results
in the destruction of the optical activity of lactose and
maltose allowing for the determination of sucrose by a
single polarimetric measurement (4). Sucrose has also been
determined by this method in the presence of glucose and
fructose by the addition of borax (2) and boron salts (17).
The direct polarimetric measurement of a sugar solution
gives the total rotation of all optically active species
present, and is, consequently, a correct measure of the
sucrose content only if the other substances present have
no effective rotatory power. If other optically active
species such as nitrogen-containing compounds (29) are pre-
sent, the single polarimetric measurement must be supple-
mented by a second polarimetric determination. In this
double polarization method, the optical activities of the
impurities are kept constant while any variations in the
total optical activity of the solution results from sucrose
hydrolysis to invert sugar. The variation is known to be
an exact function of the sucrose concentration. The
hydrolysis for analytical purposes can be effected by
either hydrochloric acid or the enzyme, invertase. The
method of double polarimetric measurements with hydro-
VOL. 20 NO. 3 JULY 1979 235
chloric acid inversion is the basis of the Clerget Method
(39) .
Two modifications to this method pertaining solely to the
hydrolysis time and temperature variations exist. These
are a modification by Browne (39) recommending overnight
hydrolysis at room temperature and a modification by Jack-
son and Gillis (23) showing inversion is complete in 8
minutes at 60°C under the conditions prescribed by Browne
(39) .
Nitrogen-containing compounds exhibit different rotatory
power in a neutral or alkaline medium. Thus, for best
results both polarizations in the double polarization
methods should be performed in solutions with similar hy
drogen-ion concentrations. In a promising proposal by
Stanek (39), potassium citrate was added in amounts
stoichiometrically equivalent to the hydrochloric acid
present after acid inversion, causing the formation of
potassium chloride and citric acid. To the solution with
no HCI present, equivalent amounts of potassium chloride
and citric acid were added, so that the two solutions were
more nearly alike. Babinski and Ablamowicz (39) replaced
the potassium citrate with sodium acetate. Jackson and
Gillis (23) proposed two other methods (II and IV) for
obtaining similar solutions. In Method II, sucrose inver
sion was accomplished by HCI, then neutralized with
NH OH. To a non-inverted sucrose solution was added
amounts of NH CI to equal that formed in the inverted solu
tion. In Method IV, no NH4OH was used as in Method II and
the NH CI was replaced by NaCI. Method II is generally
applicable. Method IV is applicable in the presence of
invert sugars, but not applicable in the presence of
optically active non-sugars which change rotation with
acidity.
It should be realized that hydrolysis by acid requires
careful temperature and time regulation. Also, hydro-
chloric acid is not selective, but hydrolyzes and glyco-
236 JOURNAL OF THE A.S.S.B.T.
sidic group. Moreover, HCI influences the rotatory power
of invert sugar and many other impurities occurring in
natural products. For greater selectivity and no hydroly-
sisof impurities, the only appropriate procedure is hydroly-
sis by an enzyme specific for sucrose, e.g., invertase.
Sucrose determinations by double polarimetric measurements
with enzymatic inversion (39) were performed by procedures
similar to Browne's (39) or Jackson and Gillis' (23) modi-
fication of the Clerget Method, except invertase was used
in place of hydrochloric acid for the inversion.
Specific statements about the accuracy of each of these
polarimetric methods are difficult to make. In general,
precision for the polarimetric analysis of pure sucrose
solutions is + 0.1% (absolute) for manual determinations
and about +0.05% (absolute) for digital determinations.
Maag and Sisler (29) reported results of polarimetric
analysis to be generally high by 1 to 5% (relative) com-
pared to gas-liquid chromatography analysis (vide infra).
ISOTOPE DILUTION
Polarimetry is known to be unreliable in the presence of
optically active non-sucrose constituents. The isotope
dilution technique is not affected by interferences from
other species in solution. This technique measures the
yield of a non-quantitative process. A small amount of
radioactive sucrose is added to a sucrose solution. After
a non-quantitative purification of sucrose, the radio-
activity is measured. The extent of dilution of the radio
tracer indicates the amount of sucrose originally present.
Hirschmuller and coworkers (19,20,22) described the appli
cation of isotope dilution analysis to sucrose analysis in
sugar beets. The method of Horning and Hirschmuller (22)
required 3 to 5 days and, as such, was not useful for
rapid analysis. Sibley et al. (47) improved upon the time
constraints of the above method by reducing the experiment
time to 24 hours by streamlining the experimental proce-
dure. An accuracy of 0.1 to 0.2% (relative) was realized.
VOL. 20 NO. 3 JULY 1979 237
Mauch (32) detected a systematic error in the work of
Sibley et al. (47) and corrected it by doubling the amount
of water used in the digestion. Mauch found no systematic
error in the work of Horning ahd Hirschmuller (22). Liquid
scintillation counting techniques have been applied in iso
tope dilution studies (33) with no loss of accuracy over
gas-flow proportional counters (47), but with an increase
in the number of samples that can be analyzed, compared with
the methods described in previous reports.
CHROMATOGRAPHY
Chromatographic techniques*--paper chromatography (PC),
thin layer chromatography (TLC), high voltage paper elec
trophoresis (HVPE), ion exchange chromatography, and gas-
liquid chromatography (GLC)—have not found great applica
bility in the quantitative analysis of sucrose solutions.
The PC-Anthrone method of Sunderwirth, Olson, and Johnson
(52) used descending PC with ethyl acetate-acetic acid-
water (6:3:2) solvent system to easily separate 200 yg
each of sucrose, glucose, and fructose. The reproducibility
of the descending method was excellent using the colori-
metric anthrone method for determination of the sugar. The
standard deviation of the optical density for a 200 yg
sucrose sample was +1.6% (relative). This method allowed
for the analysis of 20 samples in 24 hours. Trojna and
Hubacek (54) separated D-glucose, D-fructose, and sucrose
by PC, enzymatically inverted sucrose, then detected the
invert sugars with a solution of either blue tetrazolium
or blue neotetrazolium. Maximum concentrations of 42 yg
D-glucose and 21 yg D-fructose per 10 milliliters of solu
tion were determined.
Fric and Kubaniova (11) separated sucrose from glucose and
fructose by PC using the solvent system butyl-alcohol acetic
acid-water (4:1:5), followed by colorimetric determination
of sucrose with triphenyl tetrazolium chloride. Accuracy
and reproducibility of the method for two samples contain-
*Colorimetric methods used with these chromatographic techniques are discussed later.
238 JOURNAL OF THE A.S.S.B.T.
30 yg and 80 yg sucrose were
3.3 yg, respectively.
Mizuna and coworkers (35) separated sugars including su
crose by PC followed by colorimetric determination using
aniline hydrogen phthalate for aldoses and phoroglucinol
for ketoses.
Mixtures of sucrose esters, sucrose, and raffinose have
been separated by silica gel TLC on glass strips (14).
Separated species were eluted from the silica gel and
measured for sucrose content by the resorcinol-hydrochloric
acid colorimetric method of Roe (44). Raadsveld and Klomp
(43) described the determination of sucrose in the pre
sence of blucose and lactose after separation on cellulose
powder MN300 using water-ethyl acetate-pyridine (25:100:35)
solvent system. The standard deviation of the sucrose
analysis was (relative).
Welch and Martin (59) quantitated glucose, fructose and
sucrose using TLC and densitometry. The solvent system
employed was ethyl acetate-pyridine-water (8:2:1). The
relative standard deviation for sucrose in the concentra
tion range 6.00 to 14.73% was 7.2 to 15.1%.
Mabry and coworkers (30)applied HVPE to the separation of
sucrose in urine samples. Quantitation was accomplished
by densitometry with a standard deviation for sucrose deter-
minations of +9% at the 120 mg sucrose concentration level.
This method allowed for the analysis of 16 to 24 samples
per day.
Sinner, Simatupang and Dietrichs (50) demonstration the
use of borate complex ion exchange chromatography for the
separation and quantitation of sugars, including sucrose.
Sugars were determined colorimetrically with 0.1% orcinol
in concentrated sulfuric acid. Deviation of the individual
peak areas was about (relative) for repeated injection
of a sugar mixture. For quantitative measurement, of
VOL. 20 NO. 3 JULY 1979 239
sample was used for this separation technique requiring
70 to 90 minutes per separation.
The most promising chromatographic method for sucrose ana
lysis in sugar beet juices is the GLC method of Karr and
Norman (25). Separation was accomplished on a column pack
ed with 10% OV-17 (phenylmethyl-silicone) liquid phase on
Chromosorb W, 80/100 mesh. Precision was about
(relative) using trehalose as an internal standard. Su
crose concentrations ranged from 9.31 to 12.94 yg sucrose
per 100 of sample with standard deviation of yg
per 100 of sample.
NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY
Maciel and Lowman (31) quantitated sucrose content in sugar
beet juices by proton NMR. The method applied a new sol-
vent resonance elimination technique — Time Resolution
Water Eliminated Fourier Transform (TRWEFT) NMR - to re-
move the large water resonance from the proton NMR spectrum.
The TRWEFT NMR technique used an added paramagnetic relax-
ation reagent to preferentially relax the water protons
over the protons to be quantitated. The water resonance
was removed from the NMR spectrum by pre-truncating the
Free Induction Decay prior to calculation of the NMR power
spectrum. TRWEFT NMR with an internal standard gave a
linear response over the sucrose concentration range 0.0
to 0.810 M (i.e., 0.0 to 26.0 weight/weight % in water).
Accuracy for sucrose analysis in sugar beet juices was 0.50%
(absolute) relative to gas-liquid chromatographic analysis.
Precision for one solution was better than (abso
lute) at a sucrose concentration of 15.00%.
COLORIMETRY AND SPECTROPHOTOMETRY
Sucrose in 1.0 M HCI at 80°C hydrolyzes rapidly to glucose
and fructose. Fructose under the same conditions for a
period of 9.25 hours produces an ultraviolet chromophore
that is stable for 2 hours (12). The chromophore inten-
sity is a direct function of the sucrose concentration and,
as such, forms the basis for a simple, sensitive coloimetric
240 J O U R N A L OF T H E A.S.S.B.T.
method of sucrose analysis. As little as 10 M sucrose can
be analyzed by this method in the absence of interfering
chromophores. The chromophore produced from the acid degra-
dation of fructose was found to be hydroxymethylfurfural
by thin layer chromatographic studies (12, 13). Furfurals,
after formation from sugars, have also been analyzed by
complex formation with azulene (46).
Analysis of small quantities of sucrose, on the order of
10-100 yg, has been performed colorimetrically by quanti
tation of the chromophore produced by the reaction of su
crose with anthrone (55). The chromophore formed was a
complex between anthrone and the fructose moiety of su
crose. Non-reducing fructosides (e.g., raffinose, melizi-
lose, and inulin) interfered.
The anthrone colorimetric technique has been employed in
numerous other investigations involving sucrose (9,36,37,
40,42,57,61). Accuracy to +_2% (relative) is obtainable for
the anthrone colorimetric method for typical sugar factory
samples containing about 0.2 yg of sucrose per milliliter
(51) .
Johnson et al. (24) combined enzymatic inversion of sucrose
by invertase with the anthrone method for determination of
sucrose in the presence of fructose and glucose. The repro-
ducibility of this method for glucose and fructose was
checked using 20 samples from a standard solution. The mean
absorbance for 100 glucose was 0.2757 +3.2% and for 50
yg fructose was 0.2379 +_3.2%.
Fresenius and coworkers (10) immobilized enzymes for re-
peated in vitro analysis of sucrose. These authors immo-
bilized the enzymes saccharase, hexokinase, phosphohexose-
isomerase and glucose-6-phosphate-dehydrogenase at CNBr
activated agarose. By means of this affinity absorption
method, they determined the sucrose concentration of solu-
tions in a closed system. The reduced form of nicotina-
mide dinucleotide phosphate measured spectrophotometrically
VOL.20NO.3JULY1979 241
was regenerated by means of glutathion reductase. Stan
dard deviation for a 7% sucrose solution was +0.02% (abso
lute) .
Papa and coworkers (41) quantitated sucrose concentration
in the presence of glucose and fructose by examination of
the differential reaction rates of sucrose reacting with
ammonium molybdate. Formation of the reaction product,
molybdenum blue, was followed spectrophotometrically.
Messineo and Musarra (34) described two methods for the
determination of sucrose based upon chromophore formation
in the reaction of the fructose moiety of sucrose with
cysteine or cysteine and tryptophan. The first method is
essentially a modification of Dische's cysteine reaction
optimized for temperature and sulfuric acid concentration.
The green chromophore formed in about 10 minutes, allowing
the determination of as little as 1 of fructose in about
30 minutes. The second method was based upon formation of
a pink chromophore by complexation of tryptophan with the
fructose-cysteine hydrochloride complex formed in the first
method. This second method required about 2.5 hours per
sample and was twice as sensitive as the first method.
Guyot (16) applied Hessler's method of fructose analysis
(18) to the analysis of sucrose solutions. Hessler's
method (18) employed the colorimetric determination of the
fructose complex with either p-anisidine or 3,3'-dimethoxy-
benzidine in 85% phosphoric acid in the presence of glu
cose. This analysis was good for fructose in the range
of fructose per gram of dry cotton boll. Guyot
(16) analyzed fructose and sucrose by their reaction with
p-anisidine. This reaction produced a yellow solution
after 1.5 hours. The analysis scheme was good for
fructose or 10-160 sucrose. The reproducibility of the
analysis was +1-2% (relative).
Lunder (28) developed a colorimetric sucrose analysis
scheme based upon reduction of cupric sulfate. Standard
242 JOURNAL OF THE A.S.S.B.T.
solutions were prepared from Cu- 20 and measured spectrophoto-
metrically to obtain a standard curve over the range 100-
350 mg Cu 20. With this method, lactose, sucrose, maltose,
and glucose were determined by spectrophotometry measure
ment of the Cu 20 precipitated after reduction of the Cu(ll)
salt without the need for preparing and standardizing
titration solutions as Cajori (5) had to do.
In an earlier paragraph, the Kulka colorimetric method for
ketopentoses and ketohexoses (27) and the orcinol-sulfuric
acid method (56) for sugars were mentioned. The precision
of the sucrose analysis by these methods depended upon the
precision of the analysis for the monosaccharides, glucose
and fructose. Typical precision for glucose analysis by the
orcinol-sulfuric acid method was +l.4% (relative). The
Kulka method, based on the resorcinol-thiourea-HCI method
of Roe (44), involved the reaction of fructose with resor-
cinol in HCI with a small amount of FeCI3 present for
color enhancement. The error for fructose analysis was
+1% (relative).
ENZYMATIC ANALYSIS AND ENZYME ELECTRODES
Enzymatic analysis of sucrose has been carried out directly
by the action of the enzyme on sucrose or indirectly employ
ing sucrose selective electrodes. Von Voorst (58) re
ported the determination of lactose, maltose, and sucrose
by means of the differential action of yeast enzymes.
An 02-sensing electrode in conjunction with invertase,
mutarotase, and glucose oxidase was used by Satoh and co
workers (45) to analyze for sucrose in the range 0 to 10 mM.
The analysis scheme, measuring 02 uptake, required 3 min
utes. The standard deviation for 5 mM sucrose was +7%
(relative).
Cordonnier and coworkers (7) developed a magnetic enzyme
membrane for use in conjunction with a pO2 electrode and the
invertase-glucose oxidase enzyme system. The electrode
response was linear over the sucrose concentration range
243
TITRATION TECHNIQUES
Cajori (5) determined sucrose after acid hydrolysis in
the presence of glucose, fructose and maltose by iodometry
with an accuracy within 3% (relative). Cupric hydroxide
added to the sugar solution was reduced to Cu.O by the
sugar. The excess Cu(OH)2 reacted with an excess of potas
sium iodide, generating 12 which was quantitated by titra-
tion with sodium thiosulfate. Silin and Sapegina (48)
determined sucrose content by the difference in the amounts
of 1„ reacted before and after sucrose inversion. Raffi-
nose caused errors in this method.
Williams et. a_l. (60) investigated the quantitative oxida
tion of organic compounds including sucrose by potassium
iodate in concentrated sulfuric acid. Quantitation was
by sodium thiosulfate titration of the liberated 12. The
analytical accuracy was +1-2% (relative).
Celsi and Sarrailh (6) employed a cupric-argentimetric
reagent for the analysis of 5 to 10 ug sucrose by titra
tion of the cupric ion with KSCN. A mercurimetric titra
tion was employed by Belas and Soliman (1) for metallic
mercury liberated from K2 Hgl4 after reaction with the
aldehyde portion of sucrose. The titrant was sodium thio
sulfate. The mean recovery of sucrose over the range of
25 to 200 mg sucrose was 96.8+ 1.69%.
PHYSICAL CHEMICAL AND OTHER METHODS
Sucrose content has also been analyzed by measurement of
such physical properties as solution specific gravity (3),
viscosity (49), refractive index (21), and cryoscopic
measurements (8). Fluorometric analysis (15) of sucrose
using p-hydroxyphenyl-acetic acid as the substrate has
been accomplished over the sucrose concentration range
0.3 to 3.0 yg/ml (1 to 100 ug total). The precision was
about +_ 1.5% (relative). The method required an initial
enzymatic inversion with invertase. Katsuhiko and cowork-
244 JOURNAL OF THE A.S.S.B.T.
ers (26) microbiologically assayed mixtures of glucose,
lactose and sucrose by lactic acid bacteria.
SUMMARY REMARKS
The isotope dilution method is the ultimate method of su
crose analysis, but it is also expensive and time consum
ing. The GLC method of Karr and Norman is just as accur
ate as the isotope dilution method, easy enough to be used
routinely in the laboratory, and requires about 12 minutes
per sample. For routine analyses, the GLC method can re
place the isotope dilution method in some cases as a means
of checking other methods of sucrose analysis.
In general, sucrose analysis by polarimetry, requiring about
2 minutes per sample, gives higher percent sucrose values
than analysis of the same samples by GLC. Maag and Sisler
(29) showed the error in sucrose analysis from polarimetric
analysis to be high by 1 to 5% (relative) compared to GLC
analysis of the same samples. This is probably due to
the presence of other optically active compounds in the
juices. Sucrose concentration errors by TRWEFT NMR analy
sis are generally in the range -3.3 to 3.6% (relative)
compared to GLC analysis of the same samples. Even at the
present state of TRWEFT NMR methodology, analysis by the
TRWEFT NMR technique is more reliable than analysis by the
polarimetric method.
The invertase double polarization method may be depended
upon to give reliable results. The two methods of Jackson
and Gillis (II and IV) give inflated results due to the
hydrolysis of the reversion products. The difference be
tween the sucrose result by Jackson and Gillis' Method II
and by the invertase method gives a relative measure of the
reversion products hydrolyzed by HCI. The amino compound
content can be determined by the difference in the results
from Jackson and Gillis' Methods II and IV.
Accuracy and precision of the other sucrose analysis methods
are generally not as good as the GLC, NMR, or isotope dilu-
VOL. 20 NO. 3 JULY 1979 245
tion methods. For reasons of time constraints and ease of
analysis, use of the polarimetric method for routine su
crose analysis has not been replaced by the methods discus
sed above. In the future though, analysis of sucrose con
tent in sugar beet juices may be performed by the GLC method
or the TRWEFT NMR method on a routine basis.
LITERATURE CITED
(1) Belal, S., and R. Soliman. 1974. Application of Mecurimetric Titration in Semimicro Estimation of Some Sugars. Pharmazie, 29(3) , 205.
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(3) Beutler, R. 19 34. Determination of the Cane Sugar Content of Small Volumes of Liquid by Measuring the Specific Gravity and Specific Rotatory Power. Mikrochemi, lj[, 13 3-40.
(4) Bidinost, L. E., and W. Jung. 1959. Determination of Sucrose in the Presence of Other Sugars: Lactose and Maltose. Anales Direc. Nacl. Quim. (Buenos Aires), 12(23), 17-19.
(5) Cajori, F. A. 1922. The Use of Iodine in the Determination of Glucose, Fructose, Sucrose, and Maltose. J. Biol. Chem., 54_, 617-27.
(6) Celsi, S. A., and P. O. Sarrailh. 1965. New Cupric-Argentimetric Method for the Determination of Reducing Sugars. Ann. Pharm. F r a n c , 23 (12) , 775-80.
(7) Cordonnier, M., F. Lawny, D. Chopot, and D. Thomas. 19 75. Magnetic Enzyme Membranes as Active Elements of Electrochemical Sensors. Lactose, Saccharose, and Maltose Bienzyme Electrodes. FEBS Letters, 59 (2) , 263-7.
(8) Dixon, H. H., and T. G. Mason. 1920. Cryoscopic Method for the Estimation of Sucrose. Sci. Proc. Toy. Dubl. S o c , 16^ 1-8.
(9) Dreywood, R. 1946. Qualitative Test for Carbohydrate Material. Ind. Eng. Chem., Anal. Ed., 1_8, 499.
(10) Fresenius, R. E., K. G. Woenne, and V7. Flemming. 1974. Determination of Sucrose, Glucose, and Fructose with Carrier-bound Enzymes. Fresenius1 Z.
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(12) Garrett, E. R. , and J. Blanch. 1967. Sensitive Direct Spectrophotometric Determination of Fructose and Sucrose After Acid Degradation. Anal. Chem., 39 (10) , 1109-13.
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(15) Guilbault, G. G., P. J. Brignac, Jr., and M. Juneau. 1968. Substrates for the Fluorometric Determination of Oxidative Enzymes. Anal. Chem., 40(8), 1256-63.
(16) Guyot, H. 1961. A Study of the Hessler Technique of Photometric Determination of Fructose and Sucrose with p-Anisidine. Bull. Trans. Soc. Pharm. Lyon, 5_, 19-23.
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(19) Hirschmuller, H., and H. Horning. 1959. Sucrose Determination in Sugar Beets. Z. Zuckerind. , 9_, 390-9.
(20) Hirschmuller, H., and R. Kroecher. 1968. Sucrose Determination in Sugar Beets and Sugar Cane oy Isotope Dilution. Z. Zuckerind., 18 (9) , 475-82; 18 (11) , 587-92; 18 (18) , 649-55.
(21) Horacek, L. 1926. The Determination of Sucrose by the Interferometer. Z. Zuckerind. Ceskoslov. Rep., 51, 25-30.
(22) Horning, H., and H. Hirschmuller. 1959. Determination of Sucrose in Sugar Beets by Isotope Dilution. Z. Zuckerind., 9_* 499-507.
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(25) Karr, J., and L. W. Norman. 1974. The Determination of Sucrose in Concentrated Steffen Filtrate by Gas-Liquid Chromatography. J. Amer. Soc. Sugar Beet Technol., 18 (1) , 53-9.
(26) Katsuhiko, A., M. Hino, and N. Ikebe. 1967. Lactic Acid Bacteria Employed for Beverage Production. IV. Microbiological Assay of Mixtures of Glucose, Lactose, and Sucrose by Lactic Acid Bacteria. Nippon Nogeikagaku Kaishi, 41 (8) , 370-4.
(27) Kulka, R. G. 1956. Colorimetric Estimation of Keto-pentoses and Ketohexoses. Biochem. J., 6_3_, 542-8.
(28) Lunder, T. L. 1970. Colorimetric Determination of Sugars Starting from Methods based on the Reduction of a Cupric Sulfate Solution. Ind. Aliment. (Pinerolo, Italy), 9(3), 84-92.
(29) Maag, G. W., and G. H. Sisler. 1975. False Polarization: Quantitation and Characterization in Sugar Beet Processing Juices. J. Amer. Soc. Sugar Beet Technol., 18 (3) , 257-63.
(30) Mabry, C. C, J. D. Gryboski, and E. A. Karam. 1963. Rapid Identification and Measurement of Mono-and Oligosaccharides: An Adaptation of High-voltage Paper Electrophoresis for Sugars and Its Applicability to Biologic Materials. J. Lab. Clin. Med., 62(5), 817-830.
(31) Maciel, G. E., and D. W. Lowman. 1978. Manuscript in preparation.
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(33) McGagin, T. A., and F. G. Eis. 1968. Scintillation Counting Techniques in Isotope Dilution Analysis of Sucrose. J. Amer. Soc. Sugar Beet Technol., 15 (3) , 228-34.
(34) Messineo, L., and E. Musarra. 1972. Sensitive Spectrophotometric Determination of Fructose, Sucrose, and Inulin Without Interferences from Aldo-hexoses, Aldopentoses, and Ketopentoses. Int. J. Biochem., 3 (18) , 691-9.
248 JOURNAL OF THE A.S.S.B.T.
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Separation and Analysis of Some Sugars by Using Thin Layer
Chromatography SOULY FARAG*
Received for publication May 8, 1978
SUMMARY
Different sugars such as glucose, fructose, sucrose, raffi-
nose, and others have been separated on silica gel pre-
coated plates. The plates were doubly developed in one
direction with chloroform, acetic system consisting of
diphenylamine, aniline, and orthophosphoric acid in acetone.
The technique was used to analyze different sugars in beet
and juice samples.
INTRODUCTION
Great attention has been given recently to some relatively
rapid techniques of analysis. Thin layer chromatography
(T.L.C.) is already accepted as a laboratory tool for rou
tine work. Its low cost, ease, and rapidity along with
its capacity for separating and identifying small quanti
ties of compound mixtures make the technique a prime tool
for research as well. The objective of this investigation
was to adapt a method for separation, identification, and
approximation of different sugars in beet processing
liquors, thick juice from storage, and beet storage samples.
REAGENTS AND MATERIALS
1. Glass plates precoated with 0.25 mm dry silica gel,
EM reagents, EM Laboratories, Inc., 500 Exec. Blvd., Elms-
ford, NY 10523.
2. Solvent system which consists of a mixture of
chloroform, acetic acid, and water (3:3.5:0.5) by volume,
respectively.
* Sr. Research Chemist, U & I, Incorporated, Moses Lake, Washington 9 8837
252 JOURNAL OF THE A.S.S.B.T. 3. Spraying agent made from 1 gram diphenylamine and
1 ml of aniline in 100 ml acetone. This mixture is further
mixed with 85% orthophosphoric acid prior to use (10:1 v/v,
respectively).
PROCEDURE
1. ul is applied.
2. Dry the plate in air for approximately 30 minutes.
3. Irrigate with the solvent system in the ascending
direction in a tight container.
4. Allow the solvent to move upward about 12.5 cm.
This usually requires 90 minutes.
5. Remove the plate from the tank. Leave to dry in
air for about 30 minutes.
6. Place the plate back in the same developing solvent
and let the solvent move in the same direction to the same
distance of 12.5 cm. This usually takes 45 minutes. The
plates should then be dried in air for approximately 30
minutes.
RESULTS AND DISCUSSION
Figure 1 is a thin layer chromatogram of some standard
sugar solutions which involve glucose, fructose, sucrose,
raffmose, and a standard invert solution (0.5% each of
glucose and fructose).
Figure 2 includes some standard sugar solutions (glucose,
fructose, sucrose, and r a f f m o s e ) . It also includes a
diluted thick juice sample (26 g in 100 ml) and a diluted
diffusion juice sample (1:1 by volume).
Figure 3 is a thin layer chromatogram of standard sugar
solution (0.5% of glucose, fructose, and sucrose); and
VOL. 20 NO. 3 JULY 1979 253 also some beet storage samples (diluted 1:1 by volume).
It should be pointed out that the conventional single
development technique when using cellulose precoated plates
resulted in sucrose tailing which interfered with the
determination of other sugars. On the other hand, the com
bination of double development and silica gel plates gives
separations with minimum or no sucrose tailing and with
improved resolution of other sugars.
Direct visual comparison with known standards provided
reliable semi-quantitative information. If greater accura
cy is required on quantitative analyses, the intensity of
the spots may be measured by transmission densitometry.
It should be pointed out that this method is most suitable
for the detection of many carbohydrates present in beets
and in factory juices. Because of the simplicity of the
method and the low cost of the equipment used, it is recom-
mended for use in support of beet storage studies, thick
juice storage analysis, and screening of agriculture
research samples.
me. . 5 * 1 trf
n»ff.
.St 1 ul
Std-Invert
.5* 2 ttl
61 u.
• * • »
Figure 1. Chromatogram of standard sugar solutions.
254 JOURNAL OFTHE A.S.S.B.T.
Figure 3. Chromatogram of some beet storage samples.
Effect of Chemicals on Sucrose Loss in Sugarbeets During Storage
W. R. A K E S O N , Y. M. Y U N , A N D E. F. S U L L I V A N *
Received for publication August 15, 1978
INTRODUCTION
Chemicals are used extensively in sugarbeet production but
relatively few chemicals have been evaluated to determine
adverse effects on root quality during storage. Nemati-
cides, herbicides and insecticides are applied to soil be
fore planting, at planting or to foliage after plant
emergence, and fungicides are applied to foliage in later
stages of growth. More recently, fungicides have been
applied to sugarbeet roots after harvest to control stor
age rots (8) .
Most storage investigations have involved treatment of the
foliage prior to harvest or the roots after harvest with
materials being tested to reduce sugarbeet storage losses.
Dilley et al. (6) reported that the respiration rates of
whole beets receiving postharvest treatments of potassium
azide, Merck HZ 3456, Botron and ethylene were higher than
those of non-treated beets. Wu et al. (10) reported that
preharvest applications of Randox, and postharvest dips
in N -benzyladenine and Randox solutions reduced the loss
of sucrose, raffinose concentration, and respiration
during storage; however, several chemicals applied as pre
harvest foliar sprays or postharvest dips increased sucrose
loss, reducing sucrose accumulation, or both.
Mumford and Wyse (9) reported that Penicillium and Botrytis
Spp. will infect beets wherever the surface is injured;
*The authors are Sr. Plant Physiologist, Entomologist, and Manager-Crop Establishment and Protection, The Great Western Sugar Company, Agricultural Research Center, Longmont, CO 8 0 501.
256 JOURNAL OF THE A.S.S.B.T.
thereby, significantly increasing respiration and invert
sugar accumulation. A spray application of benomyl (Ben-
late) or thiabendazole (Mertect) at a concentration of
500 ppm prevented infection by these fungi during storage.
Thiabendazole controlled storage rot in commercial sugar-
beet piles when applied as a spray at a concentration of
1500 ppm (8).
These reports show that some preharvest and postharvest
applied chemicals increase sucrose loss and impurity ac
cumulation in whole sugarbeet roots during storage, whereas,
others may have a beneficial effect. The material pre
sented in this paper is a summation of research work con
ducted at Longmont, Colorado to determine whether a number
of commercial or potentially commercial agricultural
chemicals had any adverse effect on root quality in storage.
METHODS AND MATERIALS
HERBICIDES AND NEMATICIDES
Tests to evaluate herbicides were conducted in 1972 and
1973 and those to evaluate nematicides were conducted in
1972. Sugarbeets (GW MONO HY A 1) were grown in plots that
received herbicide treatments shown in Table 1 or nemati-
cide treatments shown in Table 2. Plots, 4 rows wide and
25 feet long, were replicated 6 times. Eighteen foot sec
tions from each row were harvested and washed. Roots from
rows 1 and 3 of each plot were analyzed immediately for
sucrose (2) and clarified juice purity (CJP) (3) while
those from rows 2 and 4 (25 to 35 lbs) were placed in
nylon net bags, identified with numbered safety pins and
placed into storage at 40 F. Thus, 12 samples of each
treatment were analyzed immediately while 12 samples were
stored. Respiration measurements were made daily as pre
viously described (1) at 40 F. Air which had been humidi
fied and scrubbed clean of carbon dioxide, flowed through
chambers containing beets, flushing out the carbon dioxide
given off by respiration of beets. The carbon dioxide was
captured in IN sodium hydroxide solution and then deter-
VOL. 20 NO. 3 JULY 1979 257 mined by back titration with 0.5 N hydrochloric acid to
phenolphthalin and. methyl orange end points. After respi
ration measurements were completed, the samples were ana
lyzed for sucrose, CJP and invert sugars (4).
GROWTH REGULATORS
A test of four growth regulators at two rates (Table 3)
each was established in 1971. The test was identical to
the herbicide and nematicide tests except that the chemi
cals were applied as foliar sprays 19 days prior to harvest.
None of the chemicals gave agronomic benefits and so were
not tested for storage loss in subsequent years.
FUNGICIDES
Evaluation of fungicides applied after harvest for control
of storage rot was made in 1976. Twenty-pound samples
were selected at random from two truck loads of machine
harvested MONO HY D2 beets. Eighteen samples were immedi
ately analyzed for sucrose and CJP. The remaining samples
were dipped in fungicide solutions shown in Table 4, for
30 seconds and then allowed to drain or were exposed to a
gaseous atmosphere of sulfur dioxide or ozone. Liquid
treatments included benomyl, thiabendazole, BayDam 18654,
Topsin M, and sulfur at 500, 1500, and 5000 ppm. Gaseous
treatments were sulfur dioxide at 1000 and 10,000 ppm for
24 hours or ozone at an undetermined concentration for two
hours. Two controls were included in the test. One con
trol received no treatment while the second was dipped in
water for 30 seconds. Eighteen replications were prepared
for each treatment. Respiration measurements were made
continuously from 7 through 133 days storage at 40 F.
When not in respiration chambers, beets were stored at
55 F for 45 days and at 40 F for the remaining time. After
104 days, 12 replications, and after 133 days, six replica
tions were analyzed for sucrose, purity and invert sugars.
Thiabendazole was evaluated in captive pile tests in 1977-
78 and 1978-79, and in a controlled temperature storage
test in 1978-79. One hundred 25-pound samples were pre-
258 JOURNAL OF THE A.S.S.B.T.
pared from a truck load of commercially harvested MONO HY
D2 beets for each test. Fifty samples were left untreated
and 50 samples were sprayed with a 1500 ppm thiabendazole
solution at the rate of 50 ml per 25 lb sample. The sam
ples were turned over and resprayed to insure complete
coverage. Thus, a total of 100 ml of solution was applied.
The samples, placed in nylon net bags and identified with
safety pins, were stored in a commercial pile at Eaton,
Colorado, for 75 days in 1977-78; a commercial pile at
Berthoud, Colorado for 120 days in 19 78-79; and in a con
trolled temperature room for 9 8 days in 1978-79. The beets
were stored in the controlled temperature room at 55 F for
50 days and 40 F for 48 days at 100% relative humidity.
The purpose of this test was to have sufficient temperature
and humidity to produce mold growth. After removal, the
samples were analyzed for weight, sucrose, purity, raffi-
nose (7) and invert sugars.
RESULTS AND CONCLUSIONS
HERBICIDES AND NEMATICIDES
The herbicides and nematicides, when applied to the soil
before planting or to the foliage after emergence, had no
adverse effects on respiration, invert sugars after storage,
or sucrose loss (Tables 1 and 2 ) . Betanal perhaps had some
effect since respiration was significantly lower while in
vert sugars and sucrose loss of beets treated with that
compound were numerically lower than the control. The two
herbicide tests were averaged together for data in Table
1. None of the chemicals tested increased any of the stor
age loss parameters which may have been due to the early
treatment and lack of chemical residue at harvest.
GROWTH REGULATORS
The growth regulators listed in Table 3 have not been used
in commercial production, but the study illustrates the
potential effect of chemicals applied to the foliage prior
to harvest on storage loss. Two chemicals had no effect
on respiration, invert sugars, or sucrose loss at either
VOL. 20 NO. 3 JULY 1979 259 Table 1. Effect of herbicides on respiration, invert sugar accumula
tion and sucrose loss during storage. Mean of two years tests.
Invert sugar after storage. Harvest invert sugar was not determined.
Table 2. Effect of nematicides on respiration, invert sugar accumulation, and sucrose loss during storage.
Invert sugar after storage - harvest invert sugars are not available.
Telone = 78% 1,3 dichloropropane.
Table 3. Effect of preharvest applied growth regulators on respiration, invert sugar accumulation, and sucrose loss.
concentration. The other two chemicals had no effect at
the lower dosages, but significantly increased respiration
rate, invert sugar accumulation, and sucrose loss when the
dosages were increased four-fold. Even though the chemi
cals were applied to the foliage, sufficient material may
have been translocated to the roots to cause toxic effects.
Since the materials were applied only 19 days prior to
harvest, chemical residues undoubtly remained in the beets
after harvest to cause the effects. The test was original
ly set up to determine whether the chemicals might reduce
storage loss as was previously reported for Randox (10).
No chemical significantly reduced the storage loss param
eters. The limited data show that one is more likely to
increase or have no effect, than reduce storage loss by
preharvest applications of growth regulator chemicals.
FUNGICIDES
Postharvest applications of fungicides to roots for con
trol of fungus diseases which cause storage rots is a new
area of investigation for eventual commercial applications.
The storage rots cause abnormally high rates of sucrose
loss when beets are stored for the longer periods {100
days or more) of time. Microorganisms causing the rots
stimulate respiration by tissue damage, invert sugar accu
mulation, and accumulation of other impurities which in
hibit crystallization, thus adversely affecting processing.
Much rot and mold growth occur as a result of poor storage
handling conditions. Mechanical injury, dehydration,
freezing and thawing, high temperatures and poor pile
260 JOURNAL OFTHE A.S.S.B.T. Table 3 Cont.
VOL. 20 NO. 3JULY 1979 261
ventilation due to trash and soil inhance rot and mold
growth. The above conditions can be improved by careful
handling and good storage practices and may not be improved
by use of fungicides. Under some conditions when beets
have been properly handled and protected as under canopies,
extensive mold growth occurs during extended storage peri
ods of over 100 days. The studies described in this sec
tion were established first to determine the effectiveness
of several selected fungicides for control of storage rots
and second to determine whether chemicals might produce
phytotoxic effects which in turn could increase storage
losses.
Respiration rates for 28-, 91- and 133-day storage periods
and invert sugar accumulation after 104- and 133-day stor
age periods for beets treated with fungicides are given in
Table 4. Benomyl and Topsin M appeared to lower respira
tion during the early period (28 days) . The respiration
rates for benomyl and Topsin M treated beets decreased
relative to the control beets with increasing concentra
tions of the respective chemicals and became significant
at 5000 ppm. Mold growth was not evident after 28 days
and so the chemicals effect on respiration was probably
not related to mold control. The effect, if any, was
short lived since no improvement in respiration was seen
for benomyl or Topsin M after 91 or 133 days. Thiabenda
zole and BayDam 18654 at 5000 ppm and sulfur dioxide at
10,000 ppm had significantly higher respiration rates than
the non-treated beets after 91 days. After 133 days all
treatments were numerically higher than both controls,
with thiabendazole, Topsin M, and BayDam 18654 at 5000 ppm,
sulfur dioxide at 10,000 ppm and ozone treatments being
significantly higher than both controls.
Benomyl treatments at 500 and 1500 ppm showed the most
promise in reducing invert sugar formation at 104 and 133
days, although they were not significantly lower than the
check. Thiabendazole at 1500 and 5000 ppm, Topsin M at
5000 ppm, BayDam 18654 at 1500 and 5000 ppm, sulfur at
Table 4. Effect of fungicides applied at harvest on respiration rate and invert sugar formation during storage.
VOL. 20 NO. 3 JULY 1979 263
5000 ppm, sulfur dioxide and ozone increased invert sugar
to significant or near significant levels. High invert
sugar formation under these conditions may have been
caused by tissue damage from the chemicals or by micro
organisms which became established as a result of earlier
tissue damage. All treatments which significantly in
creased respiration also significantly increased invert
sugar accumulation.
Sucrose losses (initial sucrose - final sucrose adjusted
for weight change) were significantly increased by the
higher concentration of thiabendazole, Topsin M, BayDam
18654, sulfur dioxide and ozone (Table 5 ) . All treatments
Table 5. Effect of fungicides applied at harvest on sucrose loss during storage.
264 J O U R N A L OF T H E A.S.S.B.T.
were numerically higher in sucrose loss than the controls
except 5000 ppm benomyl after 104 days. The sucrose
losses associated with chemical treatment are significantly
correlated with both respiration (r=0.58 for 91 days and
r=0.87 for 133 days) and invert sugar after storage (r=
0.80 for 91 days and r=0.82 for 133 days).
The treatments had a similar effect on respiration, invert
sugar and sucrose loss for both intermediate (104 days)
and long term (133 days) storage periods; however, the
differences between treatment and control became larger
with the longer storage periods. Correlation (r) between
intermediate and long term storage periods was 0.92, 0.85,
and 0.79 for respiration, invert sugar accumulation and
sucrose loss, respectively.
The control beets showed little evidence of rot and mold
even after 133 days storage. Without something to control
the chemicals would not be expected to reduce storage loss.
Several of the candidates appeared to be toxic at higher
concentrations as measured by increased respiration and
invert sugar formation. Thiabendazole at 1500 ppm applied
as a spray has been used commercially (8). Nearly three
times as much liquid can be adsorbed or absorbed by the
beet from a dip treatment than from a 2-gal. per ton. spray
treatment (unpublished data). Thus, more residue would
be left with the dip treatment than the spray treatment
and so toxicity would be expected to be greater with the
former treatment than the latter.
Sucrose and recoverable sucrose losses in Thiabendazole
treated beets (1500 ppm with spray application) were com
pared with non-treated beets in three tests in 1977-78
and 1978-79 (Table 6 ) . Recoverable sucrose losses were
significantly higher in thiabendazole treated beets than
non-treated beets stored as captive samples in commercial
piles at Eaton and Berthoud, Colorado. Recoverable sucrose
loss of thiabendazole treated beets averaged 13% greater
266 JOURNAL OF THE A.S.S.B.T.
than non-treated beets in the two tests. No significant
differences existed in sucrose loss between the two treat
ments in the Eaton and Berthoud tests, but in each case,
the purity was slightly lower in the treated beets after
storage (Table 7 ) . Little, if any, mold was observed on
the beets in either test. Losses of beets in the Eaton
test were higher than normal which may have been caused
by crown frost two days before harvest. Temperature and
moisture conditions in the third test were set up to en
courage mold growth. The sucrose and recoverable sucrose
losses in treated beets were significantly less than in
non-treated beets. Purity was also significantly better
in treated beets after storage than in non-treated beets.
Visual observations showed thiabendazole reduced mold in
the third test. These data show that thiabendazole re
duced storage losses by reducing rot and mold in beets
stored under conditions which promote mold growth, as
would occur in canopy covered piles. The treatment gave
no benefit and may actually increase losses relative to
the non-treated beets under conditions where little mold
occurs. These conditions would exist under short and
intermediate term storage periods in piles which are not
covered with a canopy.
The following conclusions have been made from the studies
reported in this paper:
1) Some chemicals increase respiration, invert sugar
formation, and sucrose loss in stored beets. The
toxicity increased with increasing dosage of the
chemical and with the chemicals applied just prior
to or after harvest.
2) None of the herbicides or nematicides applied at rec
ommended rates and times gave detectable increases in
respiration, invert sugar formation, or sucrose loss.
These materials applied early in the season would
have little residue left at harvest to produce toxic
effects in roots. New pesticide candidates, however,
should be evaluated for their effect upon storage
loss before being put into commercial use.
VOL. 20 NO. 3 JULY 1979 267 3) Fungicides are useful in reducing rot and mold under
some storage conditions (8, 9 ) , but their use should
be limited to areas of known potential problems (such
as long term storage, canopy covered piles, or a
known history of problems). If no mold problems
exist, the fungicides may increase storage losses.
4) Cultivars differ widely in respiration rate, invert
sugar accumulation, and sucrose loss (1, 5, 1 1 ) .
Cultivars could likewise vary in their storage loss
reaction to chemical treatment, but we have no evi
dence to indicate this is true.
SUMMARY
The chemicals applied early in the season such as herbi
cides or nematicides had no adverse effect on respiration,
invert sugar formation, or sucrose loss during sugarbeet
storage; however, many chemicals applied prior to or after
harvest significantly increased storage loss, no doubt
because of toxicity to the beets. The losses increased
with increasing rate of application.
Certain fungicides applied to the roots after harvest re
duced storage losses in situations where rot and mold
problems exist; however, they may increase losses where
little or no mold problems exist.
(1) Akeson, W. R. , S. D. Fox, and E. L. Stout. 1974. Effect of topping procedure on beet quality and storage losses. J. Am. Soc. Sugar Beet Technol. 18:125-135.
(2) Brown, C. A. and F. W. Zerban. 1941. Physical and chemical methods of sugar analysis. John Wiley and Sons, NY. pp. 337-374.
(3) Carruthers, A. and J. F. T. Oldfield. 1962. Methods for assessment of beet quality. In The technological value of the sugar beet. Proc. 11th C.I.T.S. pp. 224-245. Elsevier Pub. Co. NY.
(4) Carruthers, A. and A. E. Wooten. 1965. A color-metric method for determination of invert sugar in the presence of sucrose using 2,3,5 Triphenyl tetrazolium chloride. Int. Sugar J. 57:193-194.
(5) Cole, D. R. 1977. Effect of cultivar and mechanical damage on respiration and storability of sugar-beet roots. J. Am. Soc. Sugar Beet Technol. 19: 240-245.
(6) Dilley, D. R., R. R. Wood, and P. Brimhall. 1970. Respiration of sugar beets following harvest in relationship to temperature, mechanical injury and selected chemical treatment. J. Am. Soc. Sugar Beet Technol. 15:288-293.
(7) McCready, R. M. and J. C. Goodwin. 1966. Sugar transformation in stored sugarbeets. J. Am. Soc. Sugar Beet Technol. 14:197-205.
(8) Miles, W. G., R. M. Shake, and A. Kent Nielson. 1978. The control of beet rotting fungi in sugar-beet piles by TBZ in Washington. 20th Meeting ASSBT, San Diego, CA. Feb. 26-March 2, 1978.
(9) Mumford, D. L. and R. E. Wyse. 1976. Effect of fungus infection on respiration and reducing sugar accumulation of sugarbeet roots and use of fungicides to reduce infection. J. Am. Soc. Sugar Beet Technol. 19:157-162.
(10) Wu, M. T., B. Singh, J. C. Theurer, L. E. Olsen, and D. K. Salunkhe. 1970. Control of sucrose loss irfc sugarbeet during storage by chemicals and modified atmosphere and certain associated physiological changes. J. Am. Soc. Sugar Beet Technol. 16:117-127.
(11) Wyse, R. E., K. C. Theurer, and D. L. Doney. 1978. Genetic variability in post-harvest respiration rates of sugarbeet roots. Crop Sci. 18:264-266.
268 JOURNAL OF THE A.S.S.B.T. LITERATURE CITED
Effect of Injury on Respiration Rates of Sugarbeet Roots*
R. E. W Y S E AND C. L. PETERSON
Received for publication October 2, 1978
Introduction
When sugarbeets are first placed into storage, pile temper
atures are the warmest and respiration rates are the high
est (4, 6 ) . Therefore, losses during the first weeks of
storage may be an important part of the total losses
incurred. Previous workers have shown the effects of
mechanical damage and topping on respiration rates and on
sucrose losses during extended storage (1, 2, 3, 4, 7 ) ,
but little information is available on the relationship
between injury and respiration immediately after harvest.
The objective of this investigation was to determine the
effect of harvest injury on respiration rates immediately
after harvest and to determine the feasibility of using
respiration as an injury index.
Materials and Methods
To determine the effects of normal harvest procedures on
respiration, sugarbeet roots were randomly selected from
various points in the harvest, handling, and piling process
at the Fremont factory of the Northern Ohio Sugar Company.
Sugarbeet roots from a single farmer were sampled 1) from
*Cooperative Investigations of Agricultural Research, the Science and Education Administration, U. S. Department of Agriculture; the Beet Sugar Development Foundation; and the Utah State Agricultural Experiment Station and Idaho Agricultural Experiment Station. Approved as Journal Paper No. 2324, Utah Agricultural Experiment Station, Logan, Utah, 84322. The authors are Plant Physiologist, U. S. Department of Agriculture, Science and Education Administration, Agricultural Research, Crops Research Laboratory, Utah State University, Logan, Utah, 84322; and Professor of Agricultural Engineering, University of Idaho, Moscow Idaho, 83843.
270 J O U R N A L O F T H E A.S.S.B.T.
the top of a load of beets (harvester with grab-roll
screen); 2) after unloading over a grab-roll screen;
3) and after washing with a mechanical washer-piler. The
mechanical washer was a modified grab-roll screen having
small, rough protrusions on the surface of the rolls. These
rolls inflicted severe abrasion wounds on the surface of the
roots. As controls, roots from the same field were hand dug
and washed with a hose and spray nozzle. A second control
sample was taken from the grab-roll screen on the piler
before the beets entered the washer. These roots were also
hand washed. The roots were transported to East Lansing,
Michigan, for respiration analysis. Respiration measure
ments were begun two days after harvest.
In a second experiment, the effect of temperature on the
respiration rate of injured roots immediately after harvest
was determined. Roots were hand harvested between 8 and
10 a.m. Root temperature was 15° C at the time of harvest.
Injury was inflicted by dropping each root individually
150 cm onto an asphalt surface. Types of injury were
surface abrasions and some cracking. The roots were placed
in respiration chambers at 2 and 10° C and the first
respiration measurements were made less than 6 hours after
harvest. Temperatures were monitored with thermocouples
inserted 3 cm into a root of representative size. Root
temperatures stabilized at 10° C after 10 hours but re
quired 16 hours to stabilize at 2° C.
In a third experiment, hand-dug roots were topped with a
standard tare topper. Impact injury was inflicted by
dropping a 2 kg weight from 61 cm onto the surface of the
roots. Each root was impacted twice--once on each side.
The respiration rate was then monitored at 10° C for
11 days.
In a fourth experiment, the effect of injury occurring in
the harvesting and handling operation on respiration rates
was determined by comparing 8 treatments. 1) Hand dug-
untopped; hand harvested with only petioles removed;
V O L . 20 N O . 3 JULY 1979 271
2) Hand dug-topped; hand harvested with crowns removed;
3) Hand dug-machine topped; flailed and scalped with roto
beater; 4) Hand dug-gouged; topped with standard tare
machines and gouged 3 times (gouges were conic in shape,
25 to 40 mm deep and 40 mm in diameter); 5) Hand dug-
through piler; roots passed across a standard piler after
removal of the crowns with a standard tare machine;
6) Flat plate impact; beets were dropped 2 M onto a flat
metal plate; 7) Mechanically harvested-off truck; lifter-
load type harvester with samples collected from the top
of the truck in the field; 8) Mechanically harvested-off
pile; as in 7 ) , beets passed across a standard piler and
the roots collected from the storage pile.
Beets were obtained from the Beatrice station of U and I
Sugar Company in Washington and transported to the Moses
Lake research lab for analysis. Seven replications of
each treatment with 7 to 10 kg per treatment were placed
in plastic pails. Respiration rates were measured daily
for 95 days. Temperature in the chamber was maintained
at 2° C except for twice when mechanical difficulties
caused the chamber temperature to increase.
Respiration rates were measured with an automated flow-
through system. Samples of three to six beets with a
total weight of 2.5 to 8 kg were placed in 24-liter,
plastic pails. Air was introduced into each pail at a
calibrated rate of 500 ml/min. The increase in carbon
dioxide level of the air was determined with an infrared
gas analyzer. All data were corrected to standard
temperature and pressure and respiration rates were
expressed as carbon dioxide produced per kilogram fresh
weight.
Results
The respiration rates of roots sampled during the harvest
ing and handling process reflected the amount of injury
inflicted (Figure 1 ) . The hand-harvested roots with
minimal injury (topped with a tare topper) had the lowest
Figure 1. Respiration rate of sugarbeet roots subjected to various degrees of harvest and handling injury. Temperature, 10° C.
When roots were placed in storage at 10° C, respiration
rates increased rapidly to a maximum during the first
24 hours and then decreased to a stable rate after 11
days (Figure 2 ) . The injured roots reached a peak 10 hours
272 JOURNAL OF THE A.S.S.B.T.
respiration rate, and the severely injured machine-washed
beets had the highest. Each step in the handling process
caused an incremental increase in respiration that was
sustained throughout the 12 days at 10° C. These data
indicated that the effect of injury existed well beyond
the initial high respiration period. These data also
indicated the sensitivity of respiration as an indicator
of relative injury in sugarbeets.
VOL. 20 NO. 3 JULY 1979 273
before the uninjured controls and then their rate parallel
ed that of the controls. The injured roots were still
respiring at a rate 25 percent higher than that of the
hand-dug controls after 11 days.
At 2° C there was no apparent increase in respiration
during the initial 24 hours, but approximately 10 days
were required for the respiration rate to stabilize.
After 10 days the injured roots were respiring at a rate
43 percent higher than that of the hand-harvested controls.
The effect of topping and impact damage on sugarbeet root
respiration at 10° C is shown in Figure 3. Crown removal
274 J O U R N A L OF T H E A.S.S.B.T.
greatly increased respiration rates during the first 96
hours of storage. However, after this time the topped
roots respired at a lower rate than the untopped roots.
Impact injury increased the respiration rate of topped
and untopped roots by 5.6 and 8 percent, respectively.
To determine why untopped roots respired at a higher rate
than the topped roots, the respiration rate of topped and
untopped roots and crowns was determined. Roots previously
stored for 3 0 days at 5° C .were used. Roots were topped
by removing the crown at the lowest leaf scar. The crown
V O L . 20 N O . 3 JULY 1979 275
tissue removed represented 13.4 percent of the weight
of the original root. Respiration rates were then deter
mined at 5° C. The topped roots respired at a lower
rate (4.49) than the untopped roots (5.09). The crown
tissue respired at a rate approximately three-fold higher
than that of the topped root (14.1 vs. 4.49). Therefore,
the higher respiration rate of untopped roots can be
explained by the high respiration rate of the crown
tissue. The effect of topping injury can be estimated
as follows:
(7o weight of roots x resp. of roots) + (% weight of crown)
x (resp. of crowns) = Total resp.
(4.49 x 0.866) + (14.1 x 0.134) = 5.78
5.78 - 5.09 = 0.69, or 14%
Therefore, topping increased respiration rates approximately
14 percent.
The increase in respiration due to the degree of damage
and the effect of mechanical handling operations for the
95-day time period is shown in Figure 4. Figure 5 shows
the average respiration rate for each treatment for the
entire storage period. For the first 20 days the
artificially damaged treatments had higher respiration
rates than the rest of the samples. For the remainder of
the storage period, samples taken from the storage pile
and from the top of the truck had the highest respiration
rates. Considering the severe damage inflicted to the
beets in the artificial damage treatments, it is signifi
cant that the ordinary methods of handling beets resulted
in even higher rates of respiration. Hand harvested
samples either topped or untopped had consistently lower
rates of respiration than the other treatments. The
beets with crowns removed and otherwise undamaged
generally had lower rates of respiration than those with
the crowns intact, but the differences were not statisti
cally significant.
Therefore, topping increased respiration rates approximately
14 percent.
The increase in respiration due to the degree of damage
and the effect of mechanical handling operations for the
95-day time period is shown in Figure 4. Figure 5 shows
the average respiration rate for each treatment for the
entire storage period. For the first 20 days the
artificially damaged treatments had higher respiration
rates than the rest of the samples. For the remainder of
the storage period, samples taken from the storage pile
and from the top of the truck had the highest respiration
rates. Considering the severe damage inflicted to the
beets in the artificial damage treatments, it is signifi
cant that the ordinary methods of handling beets resulted
in even higher rates of respiration. Hand harvested
samples either topped or untopped had consistently lower
rates of respiration than the other treatments. The
beets with crowns removed and otherwise undamaged
generally had lower rates of respiration than those with
the crowns intact, but the differences were not statisti
cally significant.
276 JOURNAL OFTHE A.S.S.B.T.
Discussion
It was apparent that injury during harvest and handling
had a significant effect on the respiration rate of
sugarbeet roots during at least the first 10 days of
storage. Injury as slight as dropping a 2 kg weight 60
cm onto the surface of roots was readily detectable,
even on beets previously inflicted with topping injury.
Therefore, respiration should be a useful technique for
monitoring sources of injury in the handling of
sugarbeets.
Injury to sugarbeet roots during harvesting, handling,
and piling may have a significant effect on their ability
for storage. Injury not only increases respiration rates
VOL. 20 NO. 3 JULY 1979 277
but also facilitates infection by fungal agents. Mumford
and Wyse (5) found that the epidermal layer must be
broken before infection by Penicillium or Botrytis can
occur. Therefore, reducing surface injury to sugarbeet
roots should significantly reduce sucrose losses resulting
from respiration and mold growth during storage.
The respiration rate immediately after harvest is very
important, not only as a factor in sucrose loss, but also
as a producer of heat. This heat of respiration is a
major source of heat that must be removed from a storage
pile before it can be cooled significantly. The rate of
cooling during this initial period can significantly
contribute the total sucrose lost during the entire
storage period (8).
278 J O U R N A L O F T H E A.S.S.B.T.
The controversial question of whether it is better to
remove the crown near the lowest leaf scar or to merely
remove all green material was not clarified by this study.
Crown removal by knife or tare machine increased respiration
rates during the first 5-10 days of storage. However,
after this time topped beets respired at a lower rate than
did untopped beets. Apparently the higher respiration
rate of the crown tissue had a greater effect after 5-10
days than did the increased respiration resulting from
topping injury. When a field topper was used as in
Experiment 4, even though hand harvested, the beets
continued to respire at a high rate throughout the 95-day
period. The reason for this conflict may be explained
by the fact that the tare machine would inflict less
damage and leave a smoother cut than the field topper.
These results confirmed those of Akeson and colleagues (1)
which indicated that mechanically topped roots respired
faster than untopped roots during an entire 180-day period
of storage.
Numerous studies have shown that, although the crown con
tains less sucrose and has a lower purity than the root,
its contribution to recoverable sugar per acre can be
considerable (3, 9 ) . Stout and Smith (7) found that
topped beets respired faster and spoiled quicker than
untopped beets. The greatest spoilage was in beets topped
near the center of the crown and resulted from exposure
of the pith area to fungal organisms (1, 3 ) .
VOL. 20 N O . 3 JULY 1979 279
Acknowledgements
The samples for the data presented in Figure 1 were
collected by Phil Brimhall, Northern Ohio Sugar Company
(presently Michigan Sugar Company) and the respiration
analyses were run on equipment provided by Dr. David Dilley,
Michigan State University. Data in Figure 1 was previously
published in Beet Sugar Technology, p. 97. In R. A.
McGinnis (ed.), Beet Storage, 1971. The cooperation of
U and I Incorporated in providing respiration analyses
for Experiment 4 is greatly appreciated. This research
was supported in part by grants from the Beet Sugar
Development Foundation.
280 J O U R N A L OF T H E A.S.S.B.T.
Literature Cited
(1) Akeson, W. R., S. D. Fox, and E. L. Stout. 1974. Effect of topping procedure on beet quality and storage losses. J. Am. Soc. Sugar Beet Techno1. 18:125-135.
(2) Cole, D. F. 1977. Effect of cultivar and mechanical damage on respiration and storability of sugarbeet roots. J. Am. Soc. Sugar Beet Technol. 19:240-245.
(3) Dexter, S. T., M. G. Frakes, and R. E. Wyse. 1970. Storage and clear juice characteristics of topped and untopped sugarbeets grown in 14- and 28-inch rows. J. Am. Soc. Sugar Beet Technol. 16:97-105.
(4) Dilley, D. R., R. Ralph Wood, and Phillip Brimhall. 1970. Respiration of sugarbeets following harvest in relation to temperature, mechanical injury and selected chemical treatment. J. Am. Soc. Sugar Beet Technol. 15:671-683.
(5) Mumford, D. L. and R. E. Wyse. 1976. Effect of fungus infection on respiration and reducing sugar accumulation of sugarbeet roots and use of fungicides to reduce infection. J. Am. Soc. Sugar Beet Technol. 19:157-162.
(6) Oldfield, J. F. T., J. V. Dutton, and B. J. Houghton. 1971. Deduction of the optimum conditions of storage from studies of the respiration rates of beet. International Sugar Journal 73:326-330.
(7) Stout, M. and C. H. Smith. 1950. Studies on the respiration of sugarbeets as affected by bruising, by mechanical harvesting, severing into the top and bottom halves, chemical treatment, nutrition and variety. Proc. Am. Soc. Sugar Beet Technol. 6:670-679.
(8) Wyse, R. E. and R. M. Holdredge. 1975. A computer simulation model for predicting pile temperatures and sucrose losses in sugarbeet storage structures. In: Recent Developments in Sugarbeet Storage Techniques, proceedings of~the BSDF Conference, Denver, CO.
(9) Zielke, R. C. 1973. Yield, quality, and sucrose recovery from sugarbeet root and crown. J. Am. Soc. Sugar Beet Technol. 17:332-334.
Remedying Inadequate Crystallizer Capacity R. A. MCGINNIS*
Received for publication November 27, 1978
Much money is lost each year by beet-sugar manufacturers
from excessive loss of sucrose in molasses. There is too
much money involved to sell sugar at bargain prices to feed
cattle, when it can be sold for a good profit as the re
fined product.
A factory slicing 4,000 tons of beets a day and making 5%
molasses on beets, will make 1400 tons of molasses per week.
Assuming values of $300 and $37 per ton of sugar and molas
ses, respectively, the $ per ton of molasses saved by lower
ing the molasses purity one point from 61% to 60% purity
would be $5,075, or $7105 per week.
For a company slicing 5 million tons of beets per year, and
making 250,000 tons of molasses, the one unit purity drop
would involve $1.28 million. If the molasses purity was
reduced to its probable lowest practical or "normal" puri
ty value of 56%, the gain per ton of molasses would be
*Formerly Amstar Corporation/Spreckels Sugar Division, San Francisco, CA; Now Consultant, San Rafael, California
averages 60.4 5 8 . 1 - 6 3 . 7
The low values for the factories of company "A" are omitted
from the averages because they are from factories using a
special auxiliary process. The purities are Clerget num
erators over 1:1 diluted rds denominators. While several
manufacturers have made appreciable progress in reduction
of molasses purities, as a whole the overall purities are
still uneconomically high.
Figure 1 shows a flow plan for a typical raw crystalliza
tion station, consisting of a feed-supply tank for the pan,
the raw vacuum pan, a receiver (mixer) for the finished mas-
secuite from which the crystallizers are fed (in the case
of batch crystallizers these are not needed), a mingler-
reheater, and finally centrifugals to separate the molas
ses from the raw sugar.
Figure 1 . Typ ica l raw c r y s t a l l i z a t i o n equipment .
DETENTION TIMES IN EQUIPMENT
I t i s commonly a c c e p t e d among t e c h n o l o g i s t s t h a t i n o r d e r t o comple te t h e c r y s t a l l i z a t i o n o f m a s s e c u i t e which has been p r o p e r l y b o i l e d i n t h e vacuum pans w i t h t h e u s u a l p a n -d r o p p i n g t e m p e r a t u r e o f a b o u t 70°C, a t l e a s t 30 h o u r s in t h e c r y s t a l l i z e r s a r e r e q u i r e d , c o o l i n g t o a low p o i n t t e m p e r a t u r e o f 40°C. Th i s i s i n a d d i t i o n t o t h e a p p r o x i mate 4 hou r s s p e n t in t h e r e c e i v e r - Tab le 2 shows d e t e n t i o n t imes i n Nor th American f a c t o r i e s .
Table 2 . Ac tua l d e t e n t i o n t imes in hours i n raw c r y s t a l l i z i n g equipment in North American f a c t o r i e s , 1976-77 campaign. (Cour tesy Beet Sugar I n s t i t u t e ) . I t should be no ted t h a t fo r Tab l e s 1 , 2 , and 3 , t h e l e t t e r d e s i g n a t i o n s do no t r e p r e s e n t t h e same companies in each t a b l e , t o b e t t e r p r o t e c t t he anonymity.
VOL. 20 NO. 3 JULY 1979 283
Three companies using batch crystallizers with Blanchard
type agitators are not meeting this requirement; the two
companies using Lafeuille crystallizers are very deficient
in detention times, and two of the companies using continu
ous crystallizers have time shortages.
Thus even though all other variables affecting raw crys
tallization were in satisfactory condition, which of course
is not the case, these crystallizer capacity shortages need
rectification.
Addition of more crystallizer units is an unpleasant path.
A crystallizer unit today costs about $300,000 f.o.b., and
probably involves another $100,000 installed. There is
likely to be a space problem. Most factories do not have
empty spaces for such equipment, and the solution to this
might be the installation of the new vertical-type units
such as the Toury and the B.M.A., which can be placed on
the ground outside the factory building, and connected with
magma pumps.
HIGH TEMPERATURES
Since the purpose of this paper is to call attention to
this variable, it will be given more attention than other
equally important variables. A fundamental principle of
sugar crystallization is that as much as possible should
be done as far "upstream" as possible. This is, of course,
because higher temperatures are normally used with higher
purity materials, and crystallization rates are more rapid,
and there are more control variables which can be advan
tageously manipulated in the vacuum pan, such as better
agitation, sensitively adjusted supersaturation, syrup
VOL. 20 NO. 3 JULY 1979 285
additions, and others. This paper examines primarily the
variable of boiling temperature as it affects the crystal
lization rates.
All the crystallization possible should be done in the
white boiling, then all possible of the remainder in the
intermediate boiling, and the green syrup from this boil
ing serves as the feed material for the raw pans. Both
white and intermediate mixers should be kept on the full
side as much as possible, without causing problems in mix
ing the grain of different strikes of massecuite. The
centrifugals should be operating all the time between pan
drops, with no "holes" or idle periods.
In the raw crystallization system, all possible should be
accomplished in the pan, and again the raw mixer should be
kept on the full side, as considerable crystallization can
be done there. The final unit is the mingler-reheater,
and if a Stevens type is used, the upper hopper should be
kept as full as possible. One factory gains as much as
1 purity point lowering of the molasses, as compared to
keeping the level very low.
It is my opinion that most factories are not boiling their
raw strikes at temperatures as high as possible without
degrading the juice, and are thus wasting valuable crystal
lization potential.
Table 3 shows the temperatures in raw crystallization
units in 1976-77.
286 JOURNAL OF THE A.S.S.B.T.
Note that "From vacuum pan" values are the massecuite temp
eratures after being "Brixed-up," which in a pan without
absolute pressure control, often increases the temperature
over that of the rest of the boiling. Considering this,
it seems probable that only one company has consistently
carried a higher than usual boiling pattern.
EFFECT OF TEMPERATURE ON RATES OF CRYSTALLIZATION
It is a well-known "rule of thumb" among chemists that,
on an average, an increase of temperature of 10°C will
approximately double a crystallization rate. This is a
very rough approximation, and deviations from it can be
very wide, and even reversed.
Some data from the literature are reproduced to show the
temperature effects on sucrose crystallization.
VOL. 20 NO. 3 JULY 1979 287 Table 4 shows d a t a from Kukharenko, on pu re s u g a r - w a t e r s o l u t i o n s .
U n f o r t u n a t e l y n o d a t a a r e r e a d i l y a v a i l a b l e i n t h e 8 0 ° -85°C r e g i o n . S u s i e (5) conduc ted f a c t o r y s c a l e t e s t s a t 80°C, w i t h o b v i o u s l y v e r y r a p i d r a t e s o f c r y s t a l l i z a t i o n . A t t emp t s a t measu r ing such r a t e s i n t h e l a b o r a t o r y have i n d i c a t e d t h e y a r e s o r a p i d t h a t p r e c i s e c o n t r o l i s d i f f i c u l t on a s m a l l s c a l e .
Thus , i f t h e b o i l i n g t e m p e r a t u r e i s r a i s e d a s h igh a s can be done w i t h o u t d e g r a d a t i o n o f s u c r o s e o r n o n s u c r o s e s , t h e r a t e s o f c r y s t a l l i z a t i o n w i l l b e q u i t e r a p i d . A s t h e conc e n t r a t i o n o f t h e s u c r o s e i n t h e mother l i q u o r i s lowered i n t h e l a t t e r p a r t o f t h e b o i l i n g , t h e m a s s e c u i t e t e m p e r a t u r e w i l l have t o b e lowered g r a d u a l l y t o m a i n t a i n t h e s u p e r s a t u r a t i o n , and a f t e r t i g h t e n i n g , t h e pan w i l l end a t about 70°C, w i t h a maximum amount of c r y s t a l l i z a t i o n p e r formed. There w i l l b e much l e s s f o r t h e c r y s t a l l i z e r s t o
288 JOURNAL OFTHE A.S.S.B.T.
do, and if supersaturations are kept optimum in them, the
total crystallization achieved will be much more than if
the pan had accomplished less. The percent gross crystal
lization (percent on sugar in the pan feed) should be close
to 60%, and with 6 to 8% added by the crystallizers, better
molasses exhaustion should result.
The percentage of crystallization in a pan boiled by this
"hot" technique, if the massecuite is properly tightened
and dropped at 70°C will be the same as in a boiling at
a lower temperature, but much less boiling time will have
been required, and certain slow-boiling massecuites (be
cause of the nature of their nonsucroses) will crystallize
much more rapidly. There will be much less for the crys
tallizers to do, and if the factory is short of crystallizer
capacity, probably the best possible results with the exist
ing equipment will be attained.
It should be kept in mind, however, that this "hot" boil-
VOL. 20 NO. 3 JULY 1979 289
ing technique will be of much less, or no interest at all,
if the factory has ample crystallizer capacity, - enough
to give crystallizer detention times or 30 - 40 hours or
more -
Figure 4. Viscosity of typical beet molasses, 1, and pure sucrose water solution, 2, at various temperatures. Both are at 1.0 saturation (5).
VISCOSITY
When boiling at high temperatures it is necessary to keep
the rds of the massecuite high, not only because of the
more rapidly-increasing mass of crystals, but also to main
tain high enough supersaturation.
Fortunately viscosities of the syrup phases will not in
crease appreciably. The recently published work of Karad-
zik and Terek (2) shows that in the ranges of rds and
temperature which would be involved in high-temperature
boiling, the syrup viscosity changes only by a few poises
at constant saturation, and we may reasonably assume, at
constant supersaturation. This is shown clearly in Fig
ures 3 and 4.
FACTORS IMPORTANT IN HIGH-TEMPERATURE BOILING
1. The molasses produced must have a pH value higher than
6.9. If lower, milk of lime or magnesia should be added
to any of the following: intermediate boiling, raw pan
290 JOURNAL OFTHE A.S.S.B.T.
feed, or the raw pan. Do not use caustic soda or soda
ash, as these are very melassigenic.
2. Temperatures should be raised by degrees when first
trying high temperature boiling. Watch for evidences of
degradation, such as inversion, or color increase, not
only in the massecuite as discharged, but also in proof-
stick samples taken at intervals during boiling. If such
evidences are found, boiling temperatures should be lowered
several degrees. Generally a suitable boiling tempera
ture will be in the area, 80°-82°C.
3. With proper seeding with milled seed, temperatures
should be held in the high range, and the massecuite rds
held sufficiently high, and also the N/W, of course, so
that the supersaturation will be in the correct range.
The rds will surely be over 93 before the massecuite is
dropped, and the N/W over 3.0.
4. During boiling, the massecuite should be carefully
kept in the correct range; i.e., below the saturation at
which false grain would form.
5. The mass of crystals will increase more rapidly than at
lower temperatures, and after a certain point is reached,
the supersaturation cannot be held by increasing the rds
because of the high viscosity of the massecuite, and the
temperature must then be gradually lowered. Do not fail
to do this, as otherwise the supersaturations will become
too low for maximum crystal growth, once the most suitable
boiling consistency has been reached and is being main
tained.
6. When the pan is filled and Brixing-up is started,
watch for lowering temperatures, as if there is not abso
lute pressure control this will happen, and false grain
will form if the labile zone is entered.
VOL. 20 NO. 3 JULY 1979 291
7. The massecuite must circulate sufficiently during
boiling. If there is no mechanical stirrer, there must
be vapors of sufficient temperature in the calandrias.
This may mean an alteration of the factory's steam and
vapor distribution system, and the cost of the additional
energy could contra-indicate high-temperature boiling.
8. The crystallizer temperature pattern may well be about
the same as with lower-temperature boiling, with the same
low-point temperature.
9. If the factory has continuous raw centrifugals, the
high rds of the massecuite fed to them may cause diffi
culties with certain models.
Figure 5 shows the appearance of a typical pan tempera
ture-vacuum chart for an 80°C boiling. Note that the
temperature referred to is that of the majority of the
boiling, and not just that at which the massecuite is
dropped.
292 JOURNAL OF THE A.S.S.B.T.
EXAMPLES OF RESULTS OF HIGH-TEMPERATURE BOILING
It is difficult to obtain statistically-significant data,
unless all other variables are correctly set, and I have
been unable to show these figures. However, use of high-
temperature boiling has resulted in some of the lowest
purity molasses in the history of certain factories.
EFFECTS OF OTHER VARIABLES
It is obvious that raising the temperature of raw boiling
is only one of numerous ways in which the molasses exhaus
tion can be made more complete, and also that it is not
applicable under all circumstances.
Following are listed some of the other factors which fre
quently are found responsible for poor performance.
1. The raw massecuite purity should be as low as possible,
and still produce a satisfactory raw sugar, which will not
recycle too much color and floe. This is the result of
the applicatxon of the principle of doing more crystalli
zation upstream in the intermediate pan. This purity
cannot be more than 20 purity poxnts higher than the molas
ses purity desired, unless precentrifuging is used.
2. The raw pan feed syrup must be free of fine crystals,
which can be made certain by heating the raw pan feed
syrup to a temperature equal to or above that carried
in the pan. Hotter feed, flashing as it enters the pan,
can enhance massecuite circulation if properly distributed
well outside the calandria center well.
3. The pans should be seeded with milled seed slurried
in isopropanol, with the correct number of seed to yield
ample crystal surface area for crystallization, and yet
not so fine that purging will be hindered.
4. False grain must not be permitted to enter at any
point. Low purity molasses and good quality raw sugar
VOL. 20 NO. 3 JULY 1979 293 cannot be obtained with badly mixed grain.
5. The viscosity of the molasses as centrifuged should be
set the same as for molasses from lower temperature boil
ings .
6. The syrup phase should be kept in the proper super-
saturation range in all of the raw crystallization units.
Using the VanHook supersaturation formulation (same N/W
in numerator and denominator) this means 1.3 - 1.45 in the
pan, receiver, and crystallizers, and a reheating to a
little over 1.0 for centrifuging.
7. Water must not be added after the massecuite has left
the pan. Condensates from pan steamout should not be
routed to the raw pan receiver. Water is by far the most
melassigenic nonsucrose substance. If the massecuite
consistency must be reduced, and it cannot be accomplished
by raising the temperature curve, use final molasses which
has been freed of fine grain and air bubbles. It mixes in
more quickly than water, and does no damage other than
slightly reducing the syrup phase supersaturation.
8. The vacuum pan should be properly equipped, prefer
ably with a mechanical circulator; with a condenser system
which permits operation by any desired pressure; with
vacuum or absolute pressure control; a meter of some type
to permit estimation of supersaturation and perhaps consis
tency; a suitable pan thermometer capable of rapid rate of
response should be located at a point of good vapor veloc
ity in the entrainment separator, so that it measures the
vapor temperature as it leaves the massecuite surface.
Measurements taken much below the top massecuite level are
subject to considerable error, and vary with the circula
tion pattern.
9. Saturation determinations should be made by the labor
atory at appropriate intervals, either with a Saturascope
or with saturation runs, so that supersaturations can be
294 JOURNAL OF THE A.S.S.B.T.
estimated with validity.
10. If the pan does not have a mechanical circulator, there
should be sufficient vapor pressure in the calandrias to
maintain good circulation. Circulation can be accomplished
by bleeding steam or water into the boiling massecuite,
but this is very costly, energy-wise.
11. The pan receiver should be properly-sized and insula
ted, so that rapid crystallization can continue while the
massecuite is in residence there.
12. The crystallizers should have effective heat transfer
equipment and agitation. Cooling water should be control
led so that the temperature difference between the water
and the massecuite will not result in plating out crystals
on the massecuite side.
13. The interiors of the cooling elements should be cleaned
at long intervals by "boilout" or other means, to remove
microbial growths.
14. All raw crystallization equipment should be kept full
and in use at all times, growing crystals as fast as possi
ble, and this includes pans. If the pans get ahead of the
syrup supply, reduce the amount of se^d to increase grain
size.
15. Temporary high massecuite viscosities in the crystal
lizers should be relieved with raised temperatures and not
with water.
16. The massecuite that flows through the crystallizers
should be uniform.
17. All control and measuring equipment should be kept
accurately calibrated and in use at all times.
VOL. 20 NO. 3 JULY 1979 295
If a Stevens mingler is used, keep the upper hopper full
to obtain more crystallization before the massecuite
reaches the heating coils.
I hope I have gotten across the points that increased boil
ing temperatures is only one of many ways to increase
molasses exhaustion, and may not be indicated for certain
factories because of shortage of steam, or centrifugal
requirements, but if not prevented by these factors, and
for those very short of crystallizer capacity, the tech
nique can and has proved profitable.
LITERATURE CITED
(1) Eis, F. G. Personal communication.
(2) Karadzik, V. and L. Terek. 1977. Sugar J., 40 (5), (1977) Oct. pp. 29-31.
(3) Kukharenko. 1953. Quoted by Hirschmuller in P. Honig, ed., "Principles of Sugar Technology," Elsevier, Amsterdam, V. 1., pp. 24-25.
(4) M c G m n i s , R. A., P. W. Alston, S. Moore. 1942. Ind. Eng. Chem., 3± (Feb.) (1942), pp. 171-173, quoted by de Bruyn in Honig, V. 2, p. 464.
(5) Susie, S. K. 1972. "Studija o Problemu Kristalizaci je Saharoze iz necistih Rastvora," Gradevinska Knija, Belgrade (1972), pp. 99-100.
The Effect of Soil Residues of Atrazine on Sugarbeets (Beta vulgaris L.)*
R. L. ZlMDAHL, S. M. GWYNN. AND K. Z. HAUFLER
Received for publication February 1, 1979
77
31
24
11
45
36
12
24
40
0.6
2.0
2.2
(meq/lOOg)
7.8
15.8
30.5
VOL. 20 NO. 3 JULY 1979 299 Table 1
Soils used for atrazine bioassay study.
Soil textural class sand silt clay O.M. CEC
Sandy loam
Loam
Clay loam
Treated soil was stored dry in covered glass jars until
needed. Seven ounce styrofoam drinking cups, with holes
in the bottom for drainage, were used as pots. After soil
was added to the cups they were placed in a large tray in
a randomized block design with five replicates and
sub-irrigated until completely wet. Great Western Mono-Hy
D-2 sugarbeet seeds were prepared for planting by wrapping
them in paper towels and soaking them under cold, running
water for about one hour. The seeds were then transferred
to a dry paper towel and allowed to air-dry for about 15
minutes. The partially dried seeds were treated with
thiram (tetramethy1thioramidisulfide) by shaking in a
small plastic bag. Ten or more seeds were planted per
cup, and the surface of each cup was then covered with
styrofoam beads to reduce moisture loss. After emergence
plants were thinned to five per cup. Earlier experiments
had shown that length of the first true leaf (blade and
petiole) was a reliable growth measurement to predict
atrazine presence. Sugarbeets were grown 18 days in Heldt
and Ascalon soil, but it took 29 days to reach the same
growth stage in Weld soil. At these times the length of
the first true leaves for five plants per pot was measured.
FIELD STUDIES
To relate the effect of atrazine on sugarbeet growth in
the greenhouse to that observed in the field, a two-year
field experiment was performed. Corn was planted on May
15, 1975 in a randomized block with four replications.
300 J O U R N A L OF T H E A.S.S.B.T.
Atrazine was applied preemergence four days later at rates
of 2.0, 1.0, 0.5, 0.25, 0.125 and 0 lb ai/A. All plots
were hoed several times during the growing season to control
annual and perennial weeds. In October, the center two rows
of corn were hand harvested from each plot. Fresh and dry
weights were recorded and yield of corn silage was calcu-
lated in tons per acre.
In April, 1976, after plowing to about 10 inches, Mono-Hy
D-2 sugarbeet seeds were planted in the same plots. After
emergence sugarbeets were thinned to one plant per foot of
row. Sprinkler irrigation was used and hand weeding
employed as necessary in all plots to prevent excessive
weed competition. Visual injury ratings were made during
the season. In October, the center two rows of sugarbeets
in each plot were harvested. Roots were topped, washed,
weighed, and two random samples of 15 roots were analyzed
for purity and sucrose.
CHEMICAL STUDIES
To determine total residual concentrations of atrazine
present in soil at the time sugarbeets were grown, soil
samples were chemically analyzed. Soil samples from each
plot were taken in May, 1975 soon after initial atrazine
treatment. Samples were taken again at corn harvest
(October, 1975), after sugarbeets were planted (April,
1976) and following sugarbeet harvest (October, 1976). All
samples were frozen for later extraction and analysis.
Atrazine was extracted from soil by refluxing 50 g for one
hr in 90% acetonitrile/water (v/v). The extract was added
to a separatory funnel and extracted with two 25 ml portions
of methylene chloride, which were combined, dried, and
transferred to an alumina column for clean up. After
elution with benzene-ether (60:40) samples were brought
to an appropriate volume in benzene for analysis.
Atrazine was detected using an electron capture gas
VOL. 20 N O . 3 JULY 1979 301
chromatograph and a Dohrmann-Envirotech halogen specific
microcoulometer. Analysis with electron capture showed
that atrazine could be detected with a linear range of
1-10 nanograms (Ng). However, even after sample clean up,
many impurity peaks resulted, so only the microcoulometer
was used. Operating conditions were:
Injection port temperature 215°C
Column 200°C
Transfer section 280°C
Combustion oven 800°C
Outlet section 720°C
Argon flow rate 40 ml/min
Oxygen flow rate 100 ml/min
A 30 cm long 2 mm ID glass column was packed with 5% SE-30
on 60/80 mesh gas-chrom Q. On low gain with a range of 300
ohms the linear range of detection was 10 to 100 Ng.
Injection volumes from 2 to 10 μ1 were used.
RESULTS AND DISCUSSION
BI0ASSAY STUDIES
An atrazine concentration of 0.2 ppmw or higher killed
sugarbeets, while 0.1 ppmw atrazine seriously affected
sugarbeet growth in all three soil types (Table 2 ) . Data
are expressed as percent of the untreated control rather
than length of the first true leaf and represent the average
of several experiments conducted in each soil type. Curves
showing percentage of control growth vs. applied atrazine
concentration were drawn for each soil. From the regression
equations obtained for these curves, the percentage decrease
in sugarbeet growth for any applied atrazine concentration
was calculated (Table 3 ) . Although these data are impor-
tant, they have little practical value except as a general
guideline, as they are based on the quantity of atrazine
applied rather than on the amount which is available to
affect sugarbeet growth. The relationship between the two
has not been determined. Nevertheless, it Is significant
that growth was suppressed 50% in all three soils at
302 J O U R N A L OF T H E A.S.S.B.T.
Table 2 Growth of sugar-beets in the greenhouse in three soils treated with atrazine.
Atrazine concentration Growth as % of untreated controla
in soil (ppmw) sandy loam loam clay loam
0 100a 100a 100a
0.0031 89b 56b 119a
0.0063 83b 58b 92a
0.0125 82b 55b 82b
0.025 84b 20c 30c
0.05 68c 16c l1d
0.1 17d 5d 2d
0.2 0 0 0
0.4 0 0 0
0.6 0 0 0 a Values in one column followed by the same letter are not significantly different at the 1% level of probability according to Duncan's multiple range test.
Table 3
Calculated concentration of atrazine required to decrease sugarbeet growth in greenhouse bioassay studies.
Soil Growth suppression Atrazine
(%) (ppmw)
Sandy loam 10 .0050
25 .0150
50 .0590
Loam 10 .0148
25 .0184
50 .0272
Clay loam 10 .0063
25 .0087
50 .0163
V O L . 20 N O . 3 JULY 1979 303
atrazine concentrations of 0.059 ppmw or less and that
there was a difference between soils. Fifty percent growth
suppression occurred at 0.059, 0.0272 and 0.0163 ppmw in
sandy loam, loam, and clay loam soil, respectively. This
relationship is not surprising given the well documented
adsorptive characteristics of soils with higher amounts of
clay and organic matter which decrease herbicide effects.
Reflective of greater variability and the lack of precision
in measuring small amounts the same consistency between
soils was not shown for 10 and 25% growth suppression.
FIELD STUDIES
Corn yields from each atrazine treatment and the untreated
plots were not significantly different (Table 4 ) . As
determined by visual injury ratings, there was slight dam-
age to sugarbeets in plots treated with the lowest three
rates of atrazine and extensive damage in plots treated
with 1.0 and 2.0 lb ai/A. Atrazine applied at 1 or 2
lb ai/A decreased sugarbeet yield but did not affect
percent sucrose or purity. Root yields from plots treated
with 0.25 and 0.5 lb ai/A were not different from the
control while a slight and unexplained increase over the
control weight was found for 0.125 lb ai/A atrazine.
The two highest rates decreased yield more than 50%.
CHEMICAL STUDIES
Chemical analysis is necessary to relate the amount of
atrazine applied in the bioassay and in field plots. The
data in Tables 2 and 3 show that extremely small quantities
of atrazine greatly decrease growth of sugarbeets in
bioassay studies. The two highest rates of applied atra-
zine reduced sugarbeet yield in the field (Table 4 ) .
The limit of chemical detection capability using the
microcoulometer was 0.1 ppmw of atrazine present in soil.
Lower levels of atrazine can be detected by extracting
larger amounts of soil and by employing extraordinary
analytical care. These measures were beyond the scope
of the present study. Without extensive clean-up and
analytical techniques beyond our capability, we could not
detect atrazine levels at or below 0.05 ppmw or approxi-
mately 10 Ng in 50 g of soil. Eberle and Gerber (2)
chemically detected 0.04 ppm of ametryn, and biologically
detected 0.2 ppm with tame oats and 0.02 ppm with Chorella
pyrenoidosa. Thus, their chemical sensitivity was about
equal to ours but their bioassay species were not as
sensitive. In sugarbeet bioassay studies the median con-
centration was 0.05 ppmw and four concentrations were lower.
Thus, the minimum detectable concentration was 0.1 ppmw.
No atrazine was detected in these samples, but it was
detected in soil treated with 0.1 to 0.6 ppmw. If the
concentrations of atrazine applied in the field are con-
verted to ppm, with the assumption that initially applied
atrazine was uniformly distributed throughout the top three
inches of soil, one can calculate that ppm approximately
equals lb ai/A. The three lowest concentrations applied
in the field should have been detectable with our analytical
method but were not. Because the field was plowed in the
fall of 1975, atrazine was distributed through the top 10
inches of soil and further diluted. In addition, 50% or
304 J O U R N A L OF T H E A.S.S.B.T.
Table 4
The affect of atrazine on corn yield and sugarbeet yield.
V O L . 20 N O . 3 JULY 1979 305
more of the atrazine applied in 1975 would have been de-
graded by the time the sugarbeet crop was planted in 1976,
further reducing the likelihood of detecting the lowest
concentrations (3). Thus, the three lowest concentrations
could not be detected.
We concluded from the greenhouse and field studies
that sugarbeets are extremely sensitive to low residues
of atrazine. Our results also indicate that the sugarbeet
is a more sensitive analytical tool than the microcou1ometer
for detecting low levels of atrazine but perhaps not for
precise quantification. We were unable to develop a
correlation between chemical and biological analyses
because the sugarbeet plant was surprisingly more sensitive
to low soil residues of atrazine than suspected and gas
chromatographic analysis was not sensitive enough to detect
atrazine levels that the sugarbeet could. Any amount of
atrazine detected by chemical assay should alert a grower
to the distinct possibility of sugarbeet injury.
SUMMARY
A study was conducted to determine levels of residual
atrazine in soil that injure succeeding crops of sugarbeets
and to correlate the results of biological and chemical
assays. Concentrations of 0.2 ppm or higher killed sugar-
beets while 0.1 ppmw seriously affected sugarbeet growth in
three soil types. Sugarbeets are a more sensitive
analytical tool than gas-liquid chromatography with
detection by microcou1ometry. Because of this sensitivity
to low soil residues of atrazine, correlation between
biological and chemical assay was not possible. Any
amount of atrazine detected by chemical assay should alert
a grower to the distinct possibility of sugarbeet injury.
ACKNOWLEDGEMENT
The authors express their appreciation to the Grower-Great
Western Sugar Company Joint Research Committee, Inc. for
partial financial support.
306 JOURNAL OF THE A.S.S.B.T.
LITERATURE CITED
(1) Behrens, R. 1970. Quantitative determination of triazine herbicides in soils by bioassay. In Residue Reviews 32: 355-369.
(2) Eberle, D. 0. and H. R. Gerber. 1976. Comparative studies of instrumental and bioassay methods for the analysis of herbicide residues. Archives of Env. Cont. and Tox. 4: 101-118.
(3) Frank, R. 1966. Atrazine carryover in production of sugar-beets in Southwestern Ontario. Weed Sci. 14: 82-85.
(4) Zimdahl, R. L., V. H. Freed, M. L. Montgomery and W. R. Furtick. 1970. The degradation of triazine and uracil herbicides in soil. Weed Res. 10: 18-26.
The Effect of Root Dehydration on the Storage Performance of a Sugarbeet Genotype Resistant
to Storage Rot W. M. BUGBEE AND D. F. COLE
Received for publication February 14, 1979 ABSTRACT
The sugarbeet cultivar American Crystal 2 hybrid B
(2B) was superior to the storage-rot-resistant genotype
75P6 in the production of recoverable white sugar per
ton (RWST) at harvest, but 75P6 was superior to 2B after
the roots had been inoculated with Phoma betae, Botrytis
cinerea, and Penicillium claviforme and stored at 10° C
in 98% relative humidity for 106 days. The amount of rot
in 75P6 was 50% of that in 2B when roots had lost 8-10%
of their weight in storage. Dehydrated roots had lower
clear juice purity (CJP) and RWST than did turgid roots.
Severely dehydrated roots (24% weight loss) of both
genotypes did not develop more rot than turgid roots
(9% weight loss), but there was a decrease in pol sucrose,
CJP, and RWST.
INTRODUCTION
Moisture loss from sugarbeet roots because of drought
during the growing season or because of exposure to
drying conditions after harvest reportely causes the
*Plant Pathologist and Plant Physiologist, U. S. Department of Agriculture, Science and Education Admin-istration, Agricultural Research, North Dakota State University, Fargo 58105. Cooperative investigations of the U. S. Department of Agriculture and North Dakota Agricultural Experiment Station. Published with approval of the Director of the North Dakota Agricultural Experiment Station as Journal Article No. 960.
Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the U. S. Department of Agriculture, and does not imply its approval to the exclusion of other products that may not also be suitable.
308 JOURNAL OF THE A.S.S.B.T.
roots to become more susceptible to storage rot. A 9-fold
increase in rot during 19 weeks of storage at 10° C was
reported for roots that had a 15% weight loss before
storage began (5). Another report showed that when roots
with a 19% weight loss were injured, there was a 10-fold
increase in storage rot compared with a 7-fold increase
in uninjured roots (7). Greater rot in the injured roots
was attributed, in part, to reduced wound repair capa
bility in wilted roots. Exposure of root sections to
drying for 24 hrs increased susceptibility to Phoma betae,
and this susceptibility increased more rapidly on wilted
sections than on nonwilted sections above 10° C (2).
Stored roots rotted more if irrigation during the growing
period was restricted, and the benefit of fertilization
was nullified when roots were produced under drought
conditions (8) . Most of the rot was caused by P. betae.
Results from the U.S.S.R. further show that cultivars
resistant to storage rot maintain higher leaf and root
turgor than susceptible roots under drought conditions.
There might be a genetic link between drought resistance
and storage-rot resistance (9).
The Red River Valley of North Dakota and Minnesota
is the largest sugarbeet area in the U.S., and nearly
all of that area is cultivated as dryland. Our objective
was to determine the effect of water loss from stored
roots on rot caused by the major storage pathogens in
that region and to see if genetic resistance to rot
would reduce sucrose losses under moisture stress.
MATERIALS AND METHODS
Two sugarbeet (Beta vulgaris L.) genotypes were
grown for 160 days at the North Dakota Agricultural
Experiment Station, Fargo. One genotype was a commercial
cultivar, American Crystal 2 hybrid B (2B), and the other
was a breeding line, 75P6. Cultivar 2B is susceptible
to the storage rot pathogens used here. Line 75P6 was
developed at Fargo from the U.S.S.R. introduction VNIS
F526 by interpollinating six roots that were selected for
resistance to storage rot caused by Phoma betae (Oud.)
VOL. 20 NO. 3 JULY 1979 309
Frank. This line also responded with moderate resistance
to storage rot caused by Botrytis cinerea L. and
Penicillium claviforme Bainier.
Roots were harvested, washed, and divided into four
groups of 10 roots each for each of the two genotypes.
The roots of group 1 were inoculated and stored in
perforated plastic bags. Group 2 roots were stored
identically as group 1 but not inoculated. Group 3 was
inoculated and stored in open-mesh onion sacks. Group 4
was stored identically as group 3 but not inoculated.
The eight treatments were replicated 16 times in a
complete randomized block design. Storage was at 10-2° C
for 106 days. Relative humidity of circulated air in
the storeroom was about 85%, and near 100% within the
perforated plastic bags.
Inoculation was done by inserting, with a twisting
motion, an 11-mm d cork borer 8-10 mm into the root.
The end of the borer had a serrated edge to increase
wounding action and was dipped into inoculum before
wounding each root. The inoculum consisted of a mixture
of conidia from P. betae, P. claviforme Bainier, and B.
cinerea L. suspended in a 0.1% water agar.
All inoculated roots were given a rot index based
on the distance rot had progressed in both directions
from the circular wound site: 0, no rot evident; 1, rot
up to 2 mm; 2, rot up to 5 mm; 3, rot up to 10 mm; 4,
rot up to 30 mm; 5 rot up to 40 mm (Fig. 1 ) . Rot also
was measured by excising the rotted portions from the
inoculation site, weighing the rotted tissue, and
expressing rot as a percentage of the final weight of
the entire root sample. This was done on five randomly
selected roots from each bag and the other five roots
were used for quality measurements.
Sucrose was measured with a polarimeter by the cold
digestion method (3) and adjusted for root weight loss
after storage. Clear juice purity (CJP) was determined
by using the method described by Dexter and co-workers
(4). The data were summarized and statistically analyzed
using the SAS-76 computer program (1) on an IBM 370/148
310 c o m p u t e r .
JOURNAL OF THE A.S.S.B.T.
F i g . 1 . - — D i a g r a m o f r o t r e p r e s e n t e d b y t h e s h a d e d a r e a i n r e l a t i o n t o t h e w o u n d s i t e r e p r e s e n t e d b y t h e b r o k e n - l i n e c i r c l e , a n d t h e r o t i n d e x n u m b e r a s s i g n e d t o e a c h c l a s s .
RESULTS
R o o t s t h a t w e r e s t o r e d a t 1 0 ° C i n 98% r e l a t i v e
h u m i d i t y i n p e r f o r a t e d p l a s t i c b a g s f o r 106 d a y s l o s t
8 - 10% o f t h e i r o r i g i n a l w e i g h t ( T a b l e 1 ) . T h o s e s t o r e d
Table 1. --The effect of root dehydration during 106 days of storage at 10° C on weight loss and storage rot of a storage-rot susceptible (2B) and resistant (75P6) genotype
Noninoculated Inoculated storage storage
Relative humidity,% Relative humidity, % Genotype 98 85 98 85
Weight loss, % 75P6 8 d* 23 a 9 cd 24 a 2B 10 c 22 b 10 c 24 a
Rot by weight, %
75P6 2.1 c 2.5 bc
2B 5.2 a 4.0 ab
Rot index
75P6 2.4 b 2.8 b 2B 4.8 a 4.8 a
* Means of 16 replications; means followed by the same letter within each parameter are not significantly (P = 0.05) different by Duncan's multiple range test.
VOL. 20 NO. 3 JULY 1979 311 a t t h e same t e m p e r a t u r e in open-mesh sacks and exposed to c i r c u l a t i n g a i r t h a t c o n t a i n e d 85% r e l a t i v e h u m i d i t y l o s t 20 - 24% of t h e i r o r i g i n a l w e i g h t .
The amount of s t o r a g e r o t in 75P6 was l e s s than 50% of t h a t in 2B (Table 1 ) . The amount of r o t w i t h i n each geno type was n o t a f f e c t e d by t h e amount of we igh t l o s s d u r i n g s t o r a g e . A compar i son of t h e two methods of measu r ing r o t showed a p o s i t i v e c o r r e l a t i o n ( r = . 6 9 * * ) .
C u l t i v a r 2B was s u p e r i o r to 75P6 in p e r c e n t a g e s u c r o s e , CJP, and r e c o v e r a b l e w h i t e s u g a r p e r t o n (RWST) a t h a r v e s t (Table 2 ) . N o n i n o c u l a t e d r o o t s of 2B were
T a b l e 2 . — Q u a l i t y m e a s u r e m e n t s a t h a r v e s t o f a s t o r a g e - r o t r e s i s t a n t ( 7 5 P 6 ) a n d s u s c e p t i b l e ( A m e r i c a n C r y s t a l 2 h y b r i d B ) g e n o t y p e
S u c r o s e C l e a r j u i c e R e c o v e r a b l e w h i t e
G e n o t y p e c o n t e n t p u r i t y s u g a r / t o n
% % l b s K g / t
2B 1 4 . 8 2 a* 9 3 . 8 4 a 2 5 9 a 1 2 8 a 7 5 P 6 1 3 . 9 1 b 9 1 . 2 0 b 2 2 9 b 1 1 3 b
* Means of 16 replications; means followed by the same letter within each column are not significantly different (P = 0.05) by the Waller-Duncan K-ratio method of mean separation.
superior to roots of 75P6 in quality after storage of
106 days at 98% relative humidity (Table 3 ) .
Genotype 75P6 was superior to 2B in all quality
measurements after the roots were inoculated and stored
at 98% relative humidity (Table 3 ) . At harvest. 2B
produced 24 lbs more RWST (11.9 Kg/t) than 75P6 but when
infected with storage rot pathogens and stored at 98%
relative humidity, 75P6 produced 35 lbs more RWST (17.3
Kg/t) than 2B (Tables 2 and 3 ) . When inoculated and
stored under low humidity, the RWST for both genotypes
was similar.
DISCUSSION
Genotype 75P6, which has resistance to the storage
rot pathogens tested here, expressed this characteristic
312 JOURNAL OF THE A.S.S.B.T. Table 3. — T h e effect of root dehydration and storage rot on
the quality of a storage-rot susceptible (2B) and resistant (75P6) genotype during 106 days of storage at 10° C
Noninoculated Inoculated Storage Storage
Relative humidity, % Relative humidity, % Genotype 98 85 98 85
Sucrose content, % 75P6 13.77 b* 13.29 bc 14.23 ab 11.79 d
2B 14.93 a 13.98 b 12.76 c 12.46 cd
Purity, %
7 5 P 6 8 8 . 3 7 a b 8 4 . 4 0 c 8 9 . 4 2 a 7 9 . 3 0 d
2B 9 0 . 9 9 a 8 8 . 0 3 ab 8 5 . 8 9 bc 8 0 . 3 6 d
R e c o v e r a b l e w h i t e s u g a r / t o n , l b s ( K g / t )
7 5 P 6 2 1 1 b 1 8 0 c 223 ab 1 3 0 d ( 1 0 4 ) (89 ) ( 1 1 0 ) ( 6 4 )
2B 2 4 4 a 2 1 3 b 1 8 0 c 1 4 5 d ( 1 2 1 ) ( 1 0 5 ) ( 8 9 ) ( 7 1 )
* M e a n s o f 1 6 r e p l i c a t i o n s ; m e a n s f o l l o w e d b y t h e s a m e l e t t e r w i t h i n e a c h p a r a m e t e r a r e n o t s i g n i f i c a n t l y d i f f e r e n t ( P = 0 . 0 5 ) b y t h e W a l l e r - D u n c a n K - r a t i o m e t h o d o f m e a n s e p a r a t i o n .
f a v o r a b l y n o t on ly w i t h l e s s r o t t han t h e s u s c e p t i b l e c u l t i v a r 2B , b u t a l s o in e s s e n t i a l l y no l o s s of RWST when i n o c u l a t e d and s t o r e d i n h i g h h u m i d i t y . C o n v e r s e l y , t h e s u s c e p t i b l e c u l t i v a r l o s t 58 pounds of RWST (28.7 Kg/ t ) d u r i n g s t o r a g e . Thus , a t h a r v e s t , c u l t i v a r 2B was s u p e r i o r to 75P6 in y i e l d of RWST bu t i n f e r i o r to 75P6 when i n o c u l a t e d and s t o r e d in h igh h u m i d i t y . Both geno-t y p e s s u f f e r e d a s i g n i f i c a n t l o s s of 66 - 76 l b s of RWST (32.7 - 37.6 Kg/ t ) when i n f e c t e d and s t o r e d a t t h e lower h u m i d i t y . The a d v a n t a g e o f t h e g e n e t i c r e s i s t a n c e p o s s e s s e d by 75P6 was l o s t when t h e s e r o o t s were de-h y d r a t e d . We r e p o r t h e r e fo r t h e f i r s t t ime t h a t a b r e e d i n g l i n e p o s s e s s i n g g e n e t i c r e s i s t a n c e t o P . b e t a e , B. c i n e r e a , and P . c l a v i f o r m e w i l l s u f f e r a l o s s in r e c o v e r a b l e s u c r o s e comparable t o a s t o r a g e r o t s u s c e p t i b l e c u l t i v a r i f t h e r o o t s a r e a l lowed t o l o s e more t han 10% of t h e i r we igh t t h rough w a t e r l o s s d u r i n g s t o r a g e .
The q u a l i t y d e t e r i o r a t i o n o f d e h y d r a t e d r o o t s d u r i n g s t o r a g e r e p o r t e d h e r e a g r e e s w i t h o t h e r s ( 2 , 5 , 7 , 8 , 9 ) ,
VOL. 20 NO. 3 JULY 1979 313 but our results show that these losses may not be
accompanied by increased rot.
Dehydrated and infected roots of 75P6 did not suffer
an increased rot relative to the turgid roots. In fact,
there was no change in rot development within each
genotype whether dehydrated or turgid. There was a
significant decrease during storage in RWST, purity,
and pol sucrose in dehydrated, infected 75P6. Moisture
loss, coupled with infected tissue, may have caused a
sufficient increase in respiration in 75P6 to account
for the decrease in sucrose content. There is a general
phenomenon that infected resistant plant tissue respires
at a higher rate than infected susceptible tissue (6).
Therefore, the prevention of root dehydration during
storage was more important for the rot-resistant genotype
than it was for the susceptible cultivar.
LITERATURE CITED
(1) Barr, A. J., J. H. Goodnight, J. P. Sail, and J. T. Ilellwig. A user's guide to SAS 76. SAS Institute Inc., Raleigh, NC 27605.
(2) Cormack, M. W., and J. E. Moffatt. 1961. Factors influencing storage decay of sugar beets by Phoma betae and other fungi. Phytopathology 51:3-5.
(3) DeWalley, H. C. S. 1964. Methods of sugar analysis. Elsevier Publishing Co., Amsterdam, Holland, 153 pp.
(4) Dexter, S. T., M. G. Frakes, and F. w. Snyder. 1967. A rapid and practical method of determining extract-able white sugar as may be applied to the evaluation of agronomic practices and grower deliveries in the sugar beet industry. J. Am. Soc. Sugar Beet Technol. 14:433-454.
(5) Gaskill, J. O. 1950. Drying after harvest increases storage decay of sugar-beet roots. Phytopathology 40:483-486.
(6) Goodman, R. N., Z. Kiraly, and M. Zaitlin. 1967. The biochemistry and physiology of infectious plant disease. Princeton, NJ: D. Van Nostrand Co. (p.84).
(7) Kornienko, A. S. 1975. Prophylaxis of storage rot. (In Russian). Zashchhita Rastenii (Moscow) 6:21. (Translated).
JOURNAL OF THE A.S.S.B.T. (S) Larmer, F. G. 1937. Keeping quality of sugar beets
as influenced by growth and nutritional factors. J. Agr. Res. 54:185-198.
(9) Shevchenko, V. N., and Yu. S. Toporovskaya. 1975. Significance of turgor to manifestation of genetic properties of resistance to storage rot in sugar beets. (In Russian). In Effektivnye priyemy i sposoby bor'by s boleznyami Sakharnoy Svekly, pp. 20-24, Moscow. (Translated).
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