Cowpea Control (Prostko)
Every so often, I get a few inquiries about herbicides for the control of cowpea (Vigna unguiculata) (Figure 1). Unfortunately, cowpea (also known southern pea, black-eye pea, or crowder pea) can be a very difficult plant to control and not much research data is out there. In preparing our UGA Weed Science graduate students for the upcoming 2019 National Weed Science Contest, I was able to collect some good data for various herbicides (Table 1).
In summary, the following herbicides could be used for the control of cowpea depending upon the planted crop: PRE = Atrazine, Balance Flex (isoxaflutole), and Tricor (metribuzin); POST = Classic (chlorimuron), Engenia (dicamba), Enlist One (2,4-D), Envoke (trifloxysulfruon), Gramoxone (paraquat), Liberty (glufosinate), Osprey (mesosulfuron), Roundup (glyphosate), Sharpen (saflufenacil), and Stinger (clopyralid).
Figure 1. Cowpea |
Table 1. Cowpea (‘Top Pick Pinkeye Purple’) control with PRE and POST herbicides, TyTy, Georgia, 2019.1
Herbicide | Rate/A
(oz) |
Application Method
(PRE or POST) |
Test 1
Control (%) |
Test 2
Control (%) |
|
15 DAT3
(Prostko) |
20 DAT
(Culpepper) |
14 DAT
(Prostko) |
|||
Harness 7EC | 22 | PRE | 0 | 0 | 0 |
Atrazine 4L | 64 | PRE | 100 | 100 | 100 |
Diuron 4L | 26 | PRE | 0 | 0 | 0 |
Valor SX 51WG | 3 | PRE | 0 | 10 | 20 |
Pursuit 2SL | 4 | PRE | 0 | 8 | 0 |
Balance Flexx 2SC | 6 | PRE | 100 | 100 | 100 |
Callisto 4SC | 3 | PRE | 60 | 65 | 0 |
Prowl H20 3.8ASC | 48 | PRE | 0 | 5 | 0 |
Zidua 85WG | 1 | PRE | 0 | 10 | 0 |
Dual Magnum 7.62EC | 21 | PRE | 0 | 12 | 0 |
Spartan 4L | 1 | PRE | 0 | 0 | 0 |
Tricor 4L | 24 | PRE | 100 | 100 | 100 |
Enlist One 3.8SL | 13 | POST | 95 | 95 | 100 |
Buctril 4EC | 12 | POST | 50 | 70 | 30 |
Classic 25DG + COC4 | 0.5 | POST | 95 | 95 | 85 |
Select Max 0.97SC + NIS | 25 | POST | 0 | 10 | 0 |
Stinger 3SL | 8 | POST | 95 | 100 | 80 |
Engenia 5SL | 6.4 | POST | 95 | 95 | 85 |
Fusilade DX 2EC + COC | 12 | POST | 0 | 10 | 0 |
Resource 0.86EC + COC | 4 | POST | 0 | 0 | 0 |
Reflex 2SL + NIS | 12 | POST | 50 | 50 | 50 |
Liberty 2.34SL +
N-Pak AMS (2% v/v) |
22 | POST | 100 | 93 | 85 |
Sandea 75DG + NIS | 0.66 | POST | 40 | 25 | 30 |
Osprey 4.5DG + MSO | 4.6 | POST | 70 | 88 | 85 |
Accent 75DG + COC | 0.66 | POST | 65 | 75 | 60 |
Gramoxone 2SL + NIS | 32 | POST | 100 | 95 | 90 |
Facet 75DG + MSO | 16 | POST | 50 | 60 | 55 |
Sharpen 2.85SC + MSO | 2.5 | POST | 95 | 92 | 80 |
Laudis 3.5SC + MSO | 3.5 | POST | 65 | 68 | 60 |
Envoke 75DG + NIS | 0.09 | POST | 85 | 88 | 90 |
Roundup PowerMax 5.5SL | 22 | POST | 100 | 97 | 90 |
1Test 1: Planting Date = May 28; PRE = May 29; POST = June 13 (~8” tall cowpea).
2Test 2: Planting Date = June 17; PRE = June 18; POST = July 8 (~8” tall cowpea).
3DAT = days after POST treatment.
4COC = Agridex @ 1% v/v; NIS = Induce @ 0.25% v/v; MSO = MES 100 @ 1% v/v.