Residual Activity of Diclosulam Applied to Soybean on Cotton Crop in Succession

ABSTRACT: The application of alternative herbicides to replace glyphosate can affect the succession cropping due to the persistence in the soil. The aim of this work was to evaluate the residual activity of diclosulam applied to a pre-emergence soybean crop on a cotton plant grown in succession. The present study used a randomized complete block design with five replicates and seven doses of diclosulam (0, 2.19, 4.38, 8.75, 17.5, 35 and 70 g a.i. ha-1). The cotton was sown 112 days after application of the herbicide, with accumulated rainfall of 637 mm during the soybean cycle. Variables related to photosynthetic characteristics, phytointoxication, growth, components of production and productivity were evaluated in both crops. Diclosulam did not affect the soybean cultivar M7739 IPRO. The residual activity of diclosulam (35 g ha-1) on cotton caused phytointoxication at a rate of 5% at 14, 20 and 27 days after sowing (DAS). However, the components of production, productivity and the cotton fiber quality were not affected up to 70 g ha-1 of diclosulam.

摘要：替代草甘膦的新型除草剂因在土壤中具有持留特性，可能会影响后续接茬作物的种植生产。本研究旨在评估施用于大豆播前土壤的二氯磺草胺（diclosulam）对后续接茬种植棉花的残留活性影响。本研究采用随机完全区组设计，设置5次重复，共7个二氯磺草胺施药剂量梯度（0、2.19、4.38、8.75、17.5、35和70 g a.i. ha⁻¹，其中a.i.代表有效成分）。在除草剂施用112天后进行棉花播种，大豆生育期内累计降雨量达637 mm。本研究对两种作物的光合特性、植物药害、生长状况、产量构成因素与籽棉产量相关指标进行了测定。结果表明，二氯磺草胺对大豆品种M7739 IPRO无显著影响。当施用量为35 g ha⁻¹时，二氯磺草胺在棉花上的残留活性会使其在播种后14、20及27天（DAS，播种后天数）出现5%的药害症状；但当施用量最高达70 g ha⁻¹时，棉花的产量构成因素、籽棉产量及纤维品质均未受到显著影响。