Evaluation of the Effects of Plastic Mulches - Red, Black,
Olive and Control, on the Growth and Yield of Tomato A. A. James,
J. A. Sawtelle, and R. W. Griffin College of Agriculture and Human
Sciences Prairie View A&M University, Prairie View, Texas Block
3Block 2Block 1 RedOliveControl OliveControlBlack Red
ControlRedOlive INTRODUCTION Vegetable production on raised beds
with plastic mulch has become the method of choice in many parts of
the country. Crops such as muskmelons, tomatoes, peppers,
cucumbers, squash, eggplant, watermelons, and okra have shown
significant increases in earliness, yield, and fruit quality when
grown with plastic mulch. However, in order for plastic mulch to be
viable, irrigation is essential. Three major colors of mulch are
used commercially: black, clear, and white. Black mulch is used
most widely because it retards weed growth, resulting in less
chemical usage. Black is popular for cool seasons because it warms
the soil by contact, however the clear polyethylene promotes warmer
soil temperatures than black mulch. Soils under white mulch or
white-on-black mulch remain cooler because less radiant energy is
absorbed (Sweat, 2007). Red plastic mulch has been shown to
increase tomato yields and quality in some trials and reduce the
severity of early blight in others. In addition, it has been shown
to significantly increase soil temperatures. SRM-Olive transmits
near infra-red radiation, while blocking PAR and still increasing
soil temperatures. Therefore, it simultaneously generates almost as
much heat as clear mulch and suppresses weeds
(http://www.ken-bar.com/srmolive.html) RESULTS AND DISCUSSION
Results for 2009 showed that fruit weights were not significantly
different for treatments but were significantly different for block
x treatment (P < 0.05). Total weights were 26.0, 17.3, 12.1, and
16.2 kg for black, red, olive and control, respectively (Fig. 4).
Mean weights were 1.24, 0.91, 0.64 and 0.81 kg for black, red,
olive, and control, respectively (Fig. 5). An R 2 of 0.34 and a
RMSE of 0.81 kg were obtained. However, comparisons at the 0.05
level were significant between only black and olive treatments.
There was a 38% increase in total yield for the black treatment
compared to bare ground. Fruits obtained from red and black
treatments were observed to be very large and total yields were
also higher. Contrary to results from past studies, weed growth was
high under the red treatment. Olive and the control treatments
succumbed to bacterial wilt (Fig. 7) and blossom end rot. MATERIALS
AND METHODS This experiment was conducted at the Prairie View
A&M Agriculture Farm. The experimental design was a randomized
complete block design consisting of three blocks and four
treatments (Fig. 1). Treatments consisted of colored plastic
mulches red, black, olive, and the control (bare ground). The crop
planted was a vintage heirloom tomato variety Brandywine Pink. The
land was plowed and disked before bed preparation, then compost was
incorporated during the land preparation. The colored plastic
mulches and drip irrigation lines were installed on April 6 th 2009
and April 21 st 2010 (Fig. 2). Tomato seedlings were transplanted
April 8 th 2009 and April 22 nd 2010. Seedlings were transplanted
into mulched beds 6 m by 1.2 m in rows at spacing of 0.8 m. Each
plot contained 7 plants. At planting, a cup of tomato-tone was
placed at the base of the planting hole. In Figure 3, growth under
the black plastic mulch is shown. During the course of the
experiment, plants were fertigated with liquid fish fertilizer
using an E-Z Flow tank. Cages were placed around plants for support
in 2009, however, in 2010 T- posts were used because of poor
support from cages. During the course of the experiment, a number
of seedlings had to be replaced because of wind damage and poor
seedling growth. Temperature and soil moisture data were taken
between 2:00 and 4:00 pm twice a week during the course of the
experiment. Fruits were harvested 2 1/2 months after transplanting
and continued for a period of a month. Fruit size and weights were
collected and data analyzed using SAS. Fig. 6. Mean Weight for
2010. Fig. 1. Plot Design and Layout. CONCLUSIONS Results showed
significant differences between black and the other treatments.
Although the red treatment produced larger fruits, the mulch effect
was negligible. Plants from the olive treatments did not produce
high yields, contrary to the documented yield benefits of using
olive plastic mulches. Plants grown under olive mulches succumbed
to pests and diseases and produced more vegetative growth and less
fruits. Yield from the control were the lowest and were
significantly affected by weeds. Results suggest that the black
plastic mulch produced higher yields and thus would be recommended
for the growth of tomatoes. REFERENCES Sweat, M.S. 2007.
Plasticulture Technology for Vegetable Production. Cooerative
Extension Service. University of Florida. Orzolek, M.D, and W.J.
Lamont. 2008. Summary and Recommendations for the Use of Mulch
Color in Vegetable Production. Department of Horticulture - Center
for Plasticulture, The Pennsylvania State University.
http://www.ken-bar.com/srmolive.html. Fig. 1. Installation of the
drip irrigation lines. Fig. 3. Tomato Plants Black Mulch RESULTS
AND DISCUSSION In 2010 fruit weights were significantly different
for treatments at p < 0.01 level. However, comparisons were
significant at the 0.05 level between the black treatment and all
other treatments. Total weights were 26.9, 14.2, 14.1 and 8.3 kg
for black, red, olive, and control, respectively (Fig. 4). Mean
weights were 1.42, 0.71, and 0.78 and 0.46 kg for black, red,
olive, and control, respectively (Fig. 6). An R 2 of 0.27 and a
RMSE of 0.81 kg were obtained. When compared to the bare ground
control, total yield from the black, red and olive treatment
increased 69%, 42%, and 42%, respectively. Total weights were
higher for the black treatment in both years. However, total yields
for both red and olive treatments were similar, but lower for
control. In both years, plants were affected by bacterial wilt, but
a larger number were infected in 2010, particularly, bare and
olive, thus contributing to lower yields for bare and olive
treatments. In past studies, tomato appeared to respond more to red
mulch compared to black with an average 12% increase in marketable
fruit yield over a 3 year period. However, when environ- mental
conditions for plant growth are ideal, tomato response to red mulch
is minimal (Orzolek and Lamont, 2008). During the course of the
experiment temperature data were recorded. In 2009 average soil
temperatures ranged from 17 to 34 0 C and 25 to 40 0 C for 2010.
Higher temperatures were recorded for the black mulch, a factor
which may have resulted in higher weights for this treatment. Fig.
7. Bacterial wilt of tomato. OBJECTIVE To evaluate the effects of
three plastic color mulches and control (bare ground) on the growth
and yield of an heirloom tomato (Solanum lycopersicum), Brandywine
Pink. Fig. 4. Total Yield for all Treatments. Fig. 5. Mean Weight
for 2009. ACKNOWLEDGEMENTS Special thanks to Justin Duncan,
Greenhouse Manager Steve Hill, Vegetable Plots Coordinator; Farm
Worker Prairie View A&M University, College of Agriculture and
Human Sciences, Cooperative Agricultural Research Center,
Cooperative Extension Program Faculty and Staff