Title: Trends%20In%20Peanut%20Weed%20Control
1Trends In Peanut Weed Control
- Dr. Eric P. Prostko
- Extension Weed Specialist
- University of Georgia
- Tifton
December 2002
2Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
3Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
4Trends in Peanut Weed ControlStrip-Tillage
Production
Source UGA Peanut Production Surveys
5Strip-Tillage Weed Control
- timing of burndown
- paraquat, glyphosate, 2,4-D, Valor
- yellow herbicides?
- Incorporation
- Florida pusley, evening primrose, Texas millet
- perennial weeds?
6Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
7Trends in Peanut Weed ControlHerbicide
Incorporation
Source UGA Peanut Production Surveys
8Herbicide Incorporation
or
Equally as effective Center-pivot irrigation is
2-7/A cheaper!
9Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
10Trends in Peanut Weed ControlMechanical
Cultivation
Source UGA Peanut Production Surveys
11Why has mechanical cultivation declined?
- disease management
- better herbicides
- time savings
- strip-tillage increases
- fuel prices
12Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
13Trends in Peanut Weed ControlSoil-Applied
Herbicides - I
Source UGA Peanut Production Surveys
14Trends in Peanut Weed ControlSoil-Applied
Herbicides - II
Source UGA Peanut Production Surveys
15Trends in Peanut Weed ControlPostemergence
Herbicides - I
Source UGA Peanut Production Surveys
16Trends in Peanut Weed ControlPostemergence
Herbicides - II
Source UGA Peanut Production Surveys
17Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
18What 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 RD and new products
19Reduced RatesDo they work???
20The Response of Weeds to Various Cadre Rates in
Georgia
Applied EPOST (C-2LF)
Webster et al. 1997
21The Response of Weeds to Various Cadre Rates in
Georgia
Applied EPOST
Webster et al. 1997
22Hophornbeam Copperleaf ControlRandolph County,
GA - 2001
Strongarm 0.113 ozs Valor 0.75 ozs/A
Strongarm (0.45 ozs/A)
Valor (3 ozs/A)
Untreated
6 WAT
23Weed control in peanuts with reduced rates of
Strongarm and Valor, 2002.
Untreated
Valor 3 oz/A
Strongarm 0.45 oz/A
Strongarm 0.113 oz/A Valor 0.75 oz/A
Attapulgus, GA 7 WAP
24Reduced 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 to weed size, improper sprayer
calibration, environmental conditions, etc.
25What kind of grower might consider using reduced
rates?
A grower who ...
- 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
26Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
27Trends in Peanut Weed ControlTank-Mixes
- herbicides
- fungicides
- insecticides
- foliar fertilizers
- reductions in time and money
- may not be well researched or clearly labeled
28Herbicide/Fungicide Tank-Mixes
29Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
30Trends in Peanut Weed ControlWeed Shifts
Top 5 Most Common Weeds in GA Peanuts
31Tropical 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 (Holms)
32Tropical spiderwortHow bad is it?????
Grady County, GA 2001
33Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
34Herbicide 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 .
35Herbicide ResistanceSoutheast
36Glyphosate 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 11189-198
37Biotechnology Varieties Planted in the US in 2002
SourceUSDA/NASS June 2002
38Herbicide 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
39Trends in Peanut Weed ControlTopics for
Discussion
- tillage
- incorporation
- cultivation
- herbicide use
- reduced rates
- tank-mixes
- weed shifts
- resistance
- R D
40Trends 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?
41The Peanut Weed Control Toolbox
42The 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
43University of Georgia
Extension Weed Science (gaweed.com)