Efeito do residual no solo de nicosulfuron isolado e em mistura com atrazine sobre culturas agrícolas subsequentes

Abstract

The work was developed with the objective of evaluating the carry over effect in soil of nicosulfuron herbicide isolated and nicosulfuron + atrazine over soybean, bean, cotton, cucumber, sunflower and rice crops, sown in different periods after herbicides application. The experiment was carried out from November/2008 to April/2009, at FEP-UNESP, in Selviria, County/MS, with clayey soil. The experiment was conducted under conventional tillage with crops sown in 0.5 cm spacing. The experimental design was randomized complete block with 13 treatments and 4 replications per crop. Plots were scaled with 15 m2 (3m x 5m), with 10 m2 of applied central area. Treatments consisted of nicosulfuron + atrazine (30 g + 1500 g .ha-1) and nicosulfuron (60 g .ha-1) herbicides applied to the soil at 75, 60, 45, 30, 15 and 7 days before crop sowing and a check without herbicide. Considering the obtained results, it was concluded that bean (Carioca cultivar), cucumber (Caipira-Esmeralda cultivar) and sunflower (Doe M734-G3 genotype) crops may be sown 30 days after atrazine + nicosulfuron application, as soon as isolated nicosulfuron. Soybean crop (Carrera cultivar) may be sown between 15 and 30 days after nicosulfuron + atrazine application and isolated nicosulfuron, respectively. Cotton crop (DeltaOpal cultivar), may be sown after 60 and 45 days of nicosulfuron + atrazine and isolated nicosulfuron application, respectively. However, rice crop (Primavera cultivar) may be sown 60 days after nicosulfuron + atrazine and isolated nicosulfuron application.