1. Tropical Spiderwort Management in Peanut, Corn, and Soybean
Eric P. Prostko
Extension Weed Specialist
Dept. Crop & Soil Sciences
University of Georgia
Tifton

2. Control Strategies in Peanut
row spacing
* twins vs. singles
residuals
* Dual Magnum
* Strongarm
POST’s
* Gramoxone Max
* Cadre
* Basagran

4. Tropical spiderwort control in peanut as influenced by row spacing
Source: Yoder et al (FL)

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

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

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

8. How much Dual Magnum can we use?
pt/A
2.8 pts/year
90 day PHI
cost/A
$90/gal
$31.50/2.8 pts

9. Other Metolachlor Formulations
Cinch
Dupont
same as Dual II Magnum
cannot use POST
Stalwart C
Sipcam Agro USA Inc.
“old” Dual EC formulation (7.8 lbs/gal)
not labeled for peanut
Me-Too-Lachlor
Drexel
“old Dual EC formulation (8 lbs/gal)
rates are too low

10. 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

11. Tropical spiderwort control in peanuts with Strongarm @ 0
Tropical spiderwort control in peanuts with 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”)

12. Tropical spiderwort control with POST applied Strongarm, 2003
Untreated
Strongarm applied
17 DAP
Strongarm applied
31 DAP
PE-24-03
46 DAP

13. Gramoxone Max and Cadre Tank-Mixed or Split Applications?

14. Tropical spiderwort control with Gramoxone Max and Cadre
(LSD 0.05 = 11)
(LSD 0.05 = 15)
(LSD 0.05 = 22)
Tank-mix applied 17 DAP/Split applied 17 and 31 DAP

15. A B
Tropical spiderwort control in peanuts. A = untreated; B
= Cadre applied 7 DAP. Photos taken 49 DAP.

16. What About Cadre + Dual Combos?

17. Tropical Spiderwort Control with Cadre + Dual Magnum
114 DAP
LSD 0.05 = 22

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

20. Tropical Spiderwort in Field Corn
* preemergence
Dual II Magnum
Atrazine (?)
* postemergence
2,4-D
Basagran
* post-directed
Gramoxone Max
Aim
Evik

21. Tropical Spiderwort in Soybeans
* narrow rows
* preemergence
Sencor
Dual Magnum
Boundary
Canopy SP
Canopy XL
* postemergence
Basagran
* post-directed
Gramoxone Max

22. Post-Harvest Control Strategies
prevent seed production
re-growth after harvest
time before first frost
Gramoxone Max
2,4-D
tillage

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

24. Tropical Spiderwort in Australia
Weed problem for years
control in other crops important
corn
2,4-D
Dual
peanut
Pursuit
E.P. with Australian peanut farmer, Wayne Learmonte