Control de preemergencia de malezas del maíz en Trinidad

Abstract

Response of weeds and rinfed corn (Zea mays L cv. Pioneer hybrid X306) to single and combined preemergence treatments of atrazine and either alachlor or prynachlor was evaluated over a 3-year period on clay loam soils near St. Augustine, Trinidad. All herbicide treatments reduced weed growth during the first 5 weeks. Single treatments of atrazine and prynachlor caused slight injury, but none of the herbicide treatments affected the number of days to mid silking or plant population at harvest. They all gave significantly higher yields, expressed as cob numbers and weights, than the unweeded control, but the combination treatments generally gave significantly better yields than the single herbicide treatments which caused some loss of yield when compared with the clean-weeded control Bioassays with soil samples taken after the corn harvest showed phytotoxicity at 4 weeks with all herbicide treatments, except alachlor alone, and at 8 weeks residues were detected only in plots treated with atrazine alone Atrazine plus alachlor was the most effective treatment in the study combining excellent weed control with good crop tolerance and yields, and no residual activity at 8 weeks