Trends In Peanut Weed Control Dr. Eric P. Prostko Extension Weed Specialist University of Georgia...
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Transcript of Trends In Peanut Weed Control Dr. Eric P. Prostko Extension Weed Specialist University of Georgia...
Trends In Peanut Weed Control
Dr. Eric P. Prostko
Extension Weed Specialist
University of Georgia
Tifton
December 2002
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Trends in Peanut Weed ControlStrip-Tillage Production
27
1719
0
5
10
15
20
25
1995 1997 1999 2001
Year
Acr
es -
%
Source: UGA Peanut Production Surveys
Strip-Tillage Weed Control timing of burndown paraquat, glyphosate,
2,4-D, Valor yellow herbicides? Incorporation Florida pusley, evening
primrose, Texas millet perennial weeds?
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Trends in Peanut Weed ControlHerbicide Incorporation
0102030405060
1993 1995 1997 1999 2001
Source: UGA Peanut Production Surveys
Herbicide Incorporation
or
Equally as effectiveCenter-pivot irrigation is $2-7/A cheaper!
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Trends in Peanut Weed ControlMechanical Cultivation
73 7263
47
35
0
20
40
60
80
100
1993 1995 1997 1999 2001
Year
Acr
es -
%
Source: UGA Peanut Production Surveys
Why has mechanical cultivation declined?
disease management better herbicides time savings strip-tillage increases fuel prices
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Trends in Peanut Weed ControlSoil-Applied Herbicides - I
0
7
14
21
28
35
Dual Lasso
Herbicide
Acr
es -
%
1993 1995 1997 1999 2001
Source: UGA Peanut Production Surveys
Trends in Peanut Weed ControlSoil-Applied Herbicides - II
0
7
14
21
Pursuit Zorial
Herbicide
Acr
es -
%
1993 1995 1997 1999 2001
Source: UGA Peanut Production Surveys
Trends in Peanut Weed ControlPostemergence Herbicides - I
0
15
30
45
60
Paraquat (P) Paraquat +Basagran (B)
P + B + 2,4-DB
Herbicide
Acr
es -
%
1993 1995 1997 1999 2001
Source: UGA Peanut Production Surveys
Trends in Peanut Weed ControlPostemergence Herbicides - II
0
15
30
45
60
Storm Classic Cadre Poast Select
Herbicide
Acr
es -
%
1993 1995 1997 1999 2001
Source: UGA Peanut Production Surveys
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
What about reduced rates? not labeled but not illegal companies will not support
failures not a guarantee to minimize
crop rotation issues part of a total program future R&D and new
products
Reduced RatesDo they work???
The Response of Weeds to Various Cadre Rates in Georgia
0
20
40
60
80
100
P. nutsedge Y. nutsedge sicklepod
0.36 oz/A
0.72 oz/A
1.1 oz/A
1.44 oz/A
Webster et al. 1997 Applied EPOST (C-2LF)
The Response of Weeds to Various Cadre Rates in Georgia
0
20
40
60
80
100
smallflowermorningglory
annualmorningglory
cocklebur bristly starbur
0.36 oz/A
0.72 oz/A
1.1 oz/A
1.44 oz/A
Webster et al. 1997 Applied EPOST
Hophornbeam Copperleaf ControlRandolph County, GA - 2001
6 WAT
UntreatedStrongarm
(0.45 ozs/A)Valor
(3 ozs/A)
Strongarm 0.113 ozs+ Valor 0.75 ozs/A
Weed control in peanuts with reduced rates of Strongarm and Valor, 2002.
Untreated Strongarm0.45 oz/A
Valor3 oz/A
Strongarm0.113 oz/A
+Valor
0.75 oz/A
Attapulgus, GA7 WAP
Reduced rates can work if……..
The weed is susceptible good growing/application conditions exist the application is timely (small weeds)
Full rates help to overcome variability of application due toweed size, improper sprayer calibration, environmental conditions, etc.
What kind of grower might consider using reduced rates?
regularly calibrates his sprayer has irrigation or can predict when it will rain gets consistent weed control at full rates understands the difference between 2” and 4” can cover his acreage in a short time period is willing to scout his field regularly is willing to accept less than 100% weed control is not a lawyer or close friends with one
A grower who ……...
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Trends in Peanut Weed ControlTank-Mixes
herbicides fungicides insecticides foliar fertilizers reductions in time and
money may not be well
researched or clearly labeled
Herbicide/Fungicide Tank-Mixes
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Trends in Peanut Weed ControlWeed Shifts
Top 5 Most Common Weeds in GA Peanuts
Tropical spiderwortCommelina benghalensis
annual or perennial seeds and rhizomes above and below ground
flowers 1600 seeds/plant high soil moisture and
fertility problem weed in other
countries (Holm’s)
Tropical spiderwortHow bad is it?????
Grady County, GA 2001
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Herbicide ResistanceAround the World
261 Resistant Biotypes
157 Species (95 dicots and 62 monocots)
over 210,000 fields
Source: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. December 2, 2002 .
Herbicide ResistanceSoutheast
Glyphosate ResistanceThey said it was unlikely!
Horseweed
* DE (2000)
* TN (2001)
Goosegrass * Malaysia (1997)
Italian Ryegrass * Chile (2001)
Rigid Ryegrass
* Australia (1996)
* California (1998)
* South Africa (2001)
Weed Technology, 1997 11:189-198
Biotechnology Varieties Planted in the US in 2002
22
13 09
36
75
2
22
0
33
7175
0
20
40
60
80
100
Corn Cotton Soybeans
%
Insect Herbicide Stacked Total
Source:USDA/NASSJune 2002
Herbicide Resistant WeedsStrategies for Control/Prevention prevention is the key!!! utilize other weed control tactics (cultivation,
row patterns, etc). rotate herbicides with different MOA rotate crops scout fields prevent seed production clean tillage and harvesting equipment
Trends in Peanut Weed ControlTopics for Discussion
tillage incorporation cultivation herbicide use reduced rates tank-mixes weed shifts resistance R & D
Trends in Peanut Weed ControlR & D
have had a few good years (Cadre, Select, Strongarm, Valor)
peanut is a minor crop only 2 products currently
in pipeline (Spartan, Cobra) Will they make it? Do we need them?
The Peanut Weed Control Toolbox
The Future?My Predictions
limited new herbicides $25 or less on herbicides increase in reduced rates and
combinations new uses for older products increases in resistance weed shifts
– perennials– unknowns
University ofGeorgia
Extension Weed Science
(gaweed.com)