Submitted to: Research Day Abstracts: Regional Universities Research Day
Publication Type: Proceedings
Publication Acceptance Date: 10/1/2001
Publication Date: 12/16/2001
Citation: GREER, K., MIDDICK, A., BIDLACK, J., RAO, S.C., MACKOWN, C.T. 2001. HERBICIDE RESIDUE EFFECT AFTER THREE YEARS OF WHEAT-PIGEON PEA CROPPING SYSTEM. RESEARCH DAY ABSTRACTS: REGIONAL UNIVERSITIES RESEARCH DAY. Abstract p.67-68. Interpretive Summary: Abstract only
Technical Abstract: Residual effects of herbicides used to control pigweed [Amaranthus retroflexes (L.)] in pigeon peas [Cajanus cajan (L.) Millsp.] for three years were evaluated on the following winter wheat [Triticum aestivum (L.)] production after three years of use. Winter wheat was established on 20 October, 2000 shortly after harvesting pigeon peas, as a randomized complete block design with three replications and 10 herbicide (residue) treatments from the previous summer crop. The herbicide residue treatments included two rates of Authority (PRE), Cadre (POST), Lexone DF (PRE), and Poast (POST); plus hand weeded and weedy-check control plots. No additional treatmenst were applied as the wheat grew throughout the winter and spring months. On 6 June 2001, plant stand was measured and all plots were harvested to obtain biomass yield. Results indicated that wheat following pigeon pea subjected to hand weeding as well as Authority and Lexone DF herbicides, had greater plant stand and greater biomass compared with weedy-check, Cadre, and the high rate of Poast herbicide treatments. These results demonstrate that Cadre, the most effective herbicide controlling pigweed in pigeon peas, subsequently reduced plant stand and biomass of winter wheat. For this reason, Authority and Lexone DF may be the best choice for moderate control of pigweed in pigeon peas because these herbicides provided good weed control during the summer without substantial damage to subsequent winter wheat. These results concurred with results from herbicide residue experiments from the previous year.