|Jones, Kurt - UNIV. OF CENTRAL OK|
|Shantz, D. - UNIV. OF CENTRAL OK|
|Bidlack, J.E. - UNIV. OF CENTRAL OK|
Submitted to: Research Day Abstracts: Regional Universities Research Day
Publication Type: Proceedings
Publication Acceptance Date: October 1, 2000
Publication Date: October 27, 2000
Citation: Jones, K., Shantz, D., Bidlack, J., Rao, S.C., Mackown, C.T. 2000. Herbicide residue effects in a wheat-pigeon pea cropping system. Research Day Abstracts: Regional Universities Research Day. Abstract No. M&S087. Technical Abstract: While some herbicides may be effective in controlling pigweed [Amaranthus retroflexus (L.)] in pigeon peas [Cajanus cajan (L.) Millsp.] during the summer, little information is available to reveal the residual effect of these herbicides on winter wheat [Triticum aestivum (L.)] production. This study focused on the effect of herbicide residue on stand and biomass of winter wheat following pigeon peas. 'TAM 101' winter wheat was establishe on 25 October, 1999 shortly after harvesting pigeon peas, as a randomized complete block design with three replications and 10 herbicide (residue) treatments from the previous pigeon pea crop. The herbicide residue treatments included two rates of Authority (PRE), Cadre (POST), Lexone DF (PRE), and Poast (POST); plus hand-weeded and weedy control plots. No additional treatments were applied as the wheat grew throughout the winter and spring months. On 25 May 2000, plant stand was measured and all plots were harvested to obtain biomass yield. Preliminary results indicated tha wheat following pigeon peas subjected to hand weeding, as well as Authority and Lexone DF herbicides, had higher stands and biomass compared with the untreated control, Cadre, and Poast herbicide treatments. These results were interesting in that Cadre, the most effective herbicide controlling pigweed in pigeon peas, subsequently reduced stand and biomass of winter wheat. For this reason, Authority and Lexone DF may be the best choice for control of pigweed in pigeon peas because these herbicides provided good weed control during the summer without substantial damage to winter wheat.