1. Adjusting Herbicide Programs to Emerging Weed Problems in Peanut Eric P. Prostko Extension Weed Specialist University of Georgia

2. Why do “new” weed problems occur? H reliance on herbicides H decreases in cultivation H ecological shifts H herbicide resistance

3. New or Unique Weed Problems in Peanuts H tropic croton H dayflower/spider- wort H eclipta H copperleaf H spiderflower H redweed H ALS-resistant pigweed

4. Tropic Croton (Croton glandulosus) H 3rd most troublesome weed H Cadre is weak H not as competitive as other weeds H PRE - Valor or Strongarm H POST - Ultra Blazer H Cadre/Blazer tank/mixes???

5. Dayflower/Spiderwort (Commelina spp.) H Berrien, Brooks, Grady, Thomas H limited data H Roundup is weak H PRE - Dual (timing) H POST - Basagran H others???? Asiatic spreading spiderwort

6. Tropical spiderwort, Cairo, GA, 2001

7. Residual Spiderwort Control in Peanuts with Dual Magnum, Brooks County, GA Residual Spiderwort Control in Peanuts with Dual Magnum, Brooks County, GA 2.2 7.6 0 2 4 6 8 DualNo Dual Plants/ft2 Dual Magnum @ 1 pt/A Applied: July 2, 2001 Rated: August 1, 2001 b a

8. Eclipta (Eclipta prostrata) H low, moist areas H limited biology data H PRE - Strongarm, Valor, Dual, Outlook H POST - Basagran, Storm, Tough H timing is critical

9. Eclipta Control in Peanuts with POST Herbicides 0 20 40 60 80 100 Cadre Blazer Storm Basagran Tough 2,4-DB Herbicide Control (%) 2" or less 3-5" Grichar, 1997

10. Hophornbeam Copperleaf (Acalypha ostryifolia) H Randolph, Terrell H limited biology data H PRE - Valor or Strongarm H POST - Ultra Blazer, Storm

11. Hophornbeam Copperleaf Control Randolph County, GA - 2001 6 WAT UntreatedStrongarm Valor

12. Spiderflower (Cleome spp.) H Laurens County H limited data H PRE - Pursuit H POST - Pursuit, Cadre, Ultra Blazer (bloom stage)

13. Redweed (Melochia corchorifolia) H low, moist areas H hard seed coat H season long germination H PRE - Strongarm, Valor, Zorial H POST - Basagran, Storm, Cadre

14. ALS-Resistant Palmer Pigweed H Burke County H 2001 H do not use Cadre, Pursuit, Classic, Strongarm H Prowl, Sonalan, Dual, Valor, Ultra Blazer, Storm

15. Summary H Newer soil applied herbicides will help control some of the unique weed problems. H Combinations of PRE and POST treatments will provide consistent control. H Need more information about biology and competitiveness of newer weed problems in order to make better control decisions.

16. University of Georgia Extension Weed Science (gaweed.com)