Continued Investigations on the Control of Tropical Spiderwort

1. Continued Investigations on the Control of Tropical Spiderwort J. Tim Flanders and Eric P. Prostko University of Georgia APRES - 2004 San Antonio, TX

2. Tropical spiderwortCommelina benghalensis • tropical Asia/Africa native • annual or perennial • seeds and rhizomes • above and below ground flowers • 1,600-12,000 seeds/plant • alternate host of southern root-knot nematode • problem weed in other countries (Holm’s)

3. Tropical spiderwortHow bad is it????? Grady County, GA (2004)

4. Current Control Strategies in Peanut • row spacing * twins vs. singles • residuals * Dual Magnum * Strongarm • POST’s * Gramoxone Max * Cadre * Basagran * Strongarm (?)

5. Tropical spiderwort control in peanuts with Dual Magnum applied preemergence, Grady Co., 2003. Dual Magnum 7.64EC @ 1.33 pts/A

6. Tropical spiderwort control with Gramoxone Max + Dual Magnum Tank-Mixes Gramoxone Max @ 5.5 ozs/A + Dual Magnum @ 1.33 pts/A

7. A B Tropical spiderwort control in peanuts. A = untreated; B = Gramoxone Max + Dual Magnum applied 17 DAP. Photos taken 49 DAP.

8. Strongarm in Peanut • PPI or PRE • thru cracking* • not labeled for POST use at this time but working on this issue * cracking = soil displaced by germinating seedlings just prior to emergence

9. Tropical spiderwort control in peanuts with Strongarm @ 0.45 ozs/A, Grady Co., 2003. a a ab cd abc ab b c e PRE = 5 DAP EPOST = 17 DAP (2”, 3 leaf) LPOST = 31 DAP (up to 6”)

10. Tropical spiderwort control withPOST applied Strongarm, 2003 Untreated Strongarm applied 31 DAP Strongarm applied 17 DAP PE-24-03 46 DAP

11. Gramoxone Max + BasagranA good or bad idea?

12. Tropical Spiderwort control with Gramoxone + Basagran, 2003 Treatments applied 16 DAP Gramoxone Max (5.5 ozs/A) Basagran (8 ozs/A) 80/20 (0.25% v/v) All data = NS (P = 0.05)

13. Tropical Spiderwort control with Gramoxone + Dual Magnum + Basagran, 2003 Treatments applied 16 DAP Gramoxone Max (5.5 ozs/A) Dual Magnum (1.33 pts/A) Basagran (8 ozs/A) 80/20 (0.25% v/v) All data = NS (P = 0.05)

14. What about peanut injury? • when Basagran was added to Gramoxone • 20% less peanut injury • when Basagran was added to Gramoxone + Dual Magnum • 9-14% less peanut injury

15. Gramoxone Max and CadreTank-Mixed or Split Applications?

16. Tropical spiderwort control withGramoxone Max and Cadre, 2003 (LSD 0.05 = 22) (LSD 0.05 = 11) (LSD 0.05 = 15) Tank-mix applied 17 DAP/Split applied 17 and 31 DAP

17. What About Cadre + Dual Combos?

18. Tropical Spiderwort Control with Cadre + Dual Magnum, 2003 114 DAP LSD 0.05 = 22

19. What about Valor?

20. Tropical spiderwort control in peanuts with Valor applied preemergence, Grady Co., 2003. Valor 51 WP @ 3 ozs/A

21. Post-Harvest Control Test - 2003 • October 31 • after corn harvest • 6” tall TSW • 15 GPA • 4 replications • % control - 14 DAT • frost at 14 DAT

22. Tropical spiderwort control with various herbicides - 14 DAT Applied October 31, 2003 6” tall spiderwort LSD 0.05 = 13

23. Where are we doing 2004?? TSW in Peanut • PPI vs. PRE • Strongarm • Cadre vs Pursuit • split applications of Dual Magnum • 2,4-D ????? • Corn lay-bys • Aim, Evik, Gramoxone Max, Starane