Cadre and Cotton
“A Peanut Producer’s
Dilemma”
E. P. Prostko, A. S. Culpepper, T. L. Grey,
C. W. Bednarz, and W. D. Duffie
University of Georgia
Tifton
Cadre in Peanuts
18 Month Cotton Rotation
 discovered (1981)
 field tested (1989)
 EUP’s (1993-95)
 labeled (1996)
 excellent control
of nutsedge
complex
 G-E control of
many other species
Cotton in Georgia
Planted Acres 1989-2001
Acres (X 1000)
1750
1500
1250
1000
750
500
250
19
89
19
90
19
91
19
92
19
93
19
94
19
95
19
96
19
97
19
98
19
99
20
00
20
01
0
Source: GASS
Year
Cadre Injury Symptoms
 stunting
 shortened
internodes
 yellowish-orange
leaf color (lime)
 unpredictable
What do we
know about Cadre?
Cadre
Behavior in Environment
 120 day half life
 upper 12-18”
 degradation
* microbial
* photolysis??
Source: WSSA Herbicide Handbook
Factors that Promote Microbial
Degradation of Pesticides
 adequate moisture
 warm soil temperatures (75-900F)
 favorable soil pH (> 5.5)
 good aeration
Other Soil Properties that
Influence IMI Persistence
 higher OM soils
 heavier soils (i.e. more clay)
 low pH ( < 5.5)
 Why?
* Increased adsorption which
reduces herbicide availability for
microbial degradation
Now you see it,
now you don’t?
Seed Cotton Yield Response
to Cadre Residues in North
Carolina
Untreated
Cadre (0.5x)
Cadre (1X)
Cadre (2X)
5000
kg/ha
4000
3000
2000
1000
0
1992
1993-94
Year
York et al., 2000
DES 119
How much Cadre
does it take to
cause injury?
Seed Cotton Yield (lbs/A)
Cotton Yield Response to
PPI Applications of Cadre
4000
3000
*
*
2000
1000
0
0.032
0.016
0.008
0.004
0.002
0.001
0
Cadre Rate (lb ai/A)
Averaged over 2 varieties
(DP33B, SG501BG/RR)
LSD 0.05 = 336
Tifton, GA 2000
Seed Cotton Yield (lbs/A)
Cotton Yield Response to
PRE Applications of Cadre
3000
2000
*
1000
0
*
*
0.032 0.016 0.008 0.004 0.002 0.001
0
Cadre Rate (lb ai/A)
Averaged over 2 varieties
(ST4892RR/BG, ST4691BG)
LSD 0.05 = 712
Plains, GA 2000
How much yield loss
does Cadre carryover
actually cause?
Cadre Carryover in Cotton
Brooks County, GA - 2000
674 lbs
770 lbs
770 lbs
738 lbs/A
(lint yield)
1540 lbs
1348 lbs
1220 lbs
1369 lbs/A
6/09/00
Are there variety
differences?
Cotton Variety Response to
Cadre at 8 PPB - 9 WAT
ef
SG125
g
GA161
fg
AP6101
fg
FM989
def
def
BXN47
STX9903
fg
fg
ST4892
DP458
def
DP5415
fg
ef
DP33B
Delta Pearl
0
10
20
30
Injury (%)
Tifton, GA
40
50
60
Cotton Variety Response to
Cadre at 16 PPB - 9 WAT
a
SG125
bcd
cde
GA161
AP6101
abc
FM989
BXN47
ab
ab
abc
a
ab
a
STX9903
ST4892
DP458
DP5415
DP33B
Delta Pearl
0
Tifton, GA
a
20
40
60
Injury (%)
80
100
Summary
 cotton tolerant of 1/16-1/8X rates
 carryover caused 46% yield loss
 no significant variety differences
* AP 6101
* GA 161 (Phytogen)
What can growers do?
 follow 18 month restriction
 reduced rates of Cadre?
 banded applications
 Cadre on irrigated fields only?
 foliar fertilization?
 optimum pH and nutrient levels
 plant suspect fields last
University of
Georgia
Extension
Weed Science
(gaweed.com)