Cadre and CottonCadre and Cotton“A Peanut Producer’s “A Peanut Producer’s

Dilemma”Dilemma”

E. P. Prostko, A. S. Culpepper, T. L. Grey,

C. W. Bednarz, and W. D. Duffie

University of Georgia

Tifton

Cadre in PeanutsCadre in Peanuts discovered (1981)discovered (1981) field tested (1989)field tested (1989) EUP’s (1993-95)EUP’s (1993-95) labeled (1996)labeled (1996) excellent control of excellent control of

nutsedge complexnutsedge complex G-E control of many G-E control of many

other speciesother species

18 Month Cotton Rotation18 Month Cotton Rotation

Cotton in GeorgiaCotton in GeorgiaPlanted Acres 1989-2001Planted Acres 1989-2001

0

250

500

750

1000

1250

1500

1750

Year

Acr

es (

X 1

000)

Source: GASS

Cadre Injury SymptomsCadre Injury Symptoms

stuntingstunting shortened shortened

internodes internodes yellowish-orange yellowish-orange

leaf color (lime)leaf color (lime) unpredictableunpredictable

What do we What do we know about Cadre?know about Cadre?

CadreCadre Behavior in EnvironmentBehavior in Environment

120 day half life120 day half life upper 12-18”upper 12-18” degradation degradation

* microbial* microbial

* photolysis??* photolysis??

Source: WSSA Herbicide Handbook

Factors that Promote Microbial Factors that Promote Microbial Degradation of PesticidesDegradation of Pesticides

adequate moistureadequate moisture warm soil temperatures (75-90warm soil temperatures (75-9000F)F) favorable soil pH (> 5.5)favorable soil pH (> 5.5) good aerationgood aeration

Other Soil Properties that Other Soil Properties that Influence IMI PersistenceInfluence IMI Persistence

higher OM soils higher OM soils heavier soils (i.e. more clay)heavier soils (i.e. more clay) low pH ( low pH ( << 5.5) 5.5)

Why?Why?

* Increased adsorption which reduces * Increased adsorption which reduces herbicide availability for microbial herbicide availability for microbial degradationdegradation

Now you see it, Now you see it, now you don’t?now you don’t?

Seed Cotton Yield Response Seed Cotton Yield Response to Cadre Residues in North to Cadre Residues in North

CarolinaCarolina

0

1000

2000

3000

4000

5000

1992 1993-94

Year

kg/h

a

Untreated Cadre (0.5x) Cadre (1X) Cadre (2X)

York et al., 2000 DES 119

How much Cadre How much Cadre does it take to does it take to cause injury?cause injury?

Cotton Yield Response toCotton Yield Response to PPI Applications of Cadre PPI Applications of Cadre

0

1000

2000

3000

4000

0.032 0.016 0.008 0.004 0.002 0.001 0

Cadre Rate (lb ai/A)

See

d C

otto

n Y

ield

(lb

s/A

)

Averaged over 2 varieties(DP33B, SG501BG/RR) Tifton, GA 2000LSD 0.05 = 336

**

Cotton Yield Response to Cotton Yield Response to PRE Applications of CadrePRE Applications of Cadre

0

1000

2000

3000

0.032 0.016 0.008 0.004 0.002 0.001 0

Cadre Rate (lb ai/A)

See

d C

otto

n Y

ield

(lb

s/A

)

Averaged over 2 varieties(ST4892RR/BG, ST4691BG) Plains, GA 2000LSD 0.05 = 712

**

*

How much yield loss How much yield loss does Cadre carryover does Cadre carryover

actually cause?actually cause?

Cadre Carryover in CottonCadre Carryover in CottonBrooks County, GA - 2000Brooks County, GA - 2000

674 lbs 770 lbs 770 lbs

1540 lbs 1348 lbs 1220 lbs

738 lbs/A738 lbs/A(lint yield)(lint yield)

1369 lbs/A1369 lbs/A

6/09/006/09/00

Are there variety Are there variety differences?differences?

Cotton Variety Response to Cotton Variety Response to Cadre at 8 PPB - 9 WATCadre at 8 PPB - 9 WAT

0 10 20 30 40 50 60

Delta Pearl

DP33B

DP5415

DP458

ST4892

STX9903

BXN47

FM989

AP6101

GA161

SG125

Injury (%)Tifton, GA

ef

effg

deffg

fgdefdef

fgfg

g

Cotton Variety Response to Cotton Variety Response to Cadre at 16 PPB - 9 WATCadre at 16 PPB - 9 WAT

0 20 40 60 80 100

Delta Pearl

DP33B

DP5415

DP458

ST4892

STX9903

BXN47

FM989

AP6101

GA161

SG125

Injury (%)Tifton, GA

aaba

abcabab

aabc

cdebcd

a

SummarySummary

cotton tolerant of 1/16-1/8X ratescotton tolerant of 1/16-1/8X rates carryover caused 46% yield losscarryover caused 46% yield loss no significant variety differencesno significant variety differences

* AP 6101* AP 6101

* GA 161 (Phytogen)* GA 161 (Phytogen)

What can growers do?What can growers do?

follow 18 month restrictionfollow 18 month restriction reduced rates of Cadre?reduced rates of Cadre? banded applicationsbanded applications Cadre on irrigated fields only?Cadre on irrigated fields only? foliar fertilization?foliar fertilization? optimum pH and nutrient levelsoptimum pH and nutrient levels plant suspect fields last plant suspect fields last

University ofGeorgia

ExtensionWeed Science(gaweed.com)