Effects of different periods without rains occurrence in the efficacy of flumioxazin applied in soil and in the sugarcane mulch

Abstract

The present work aimed to evaluate the efficacy of flumioxazin applied over the soil or in association with sugarcane mulch, followed by different periods without the rain occurrence. The experiment was conducted in vases under greenhouse conditions in Botucatu County, São Paulo, Brazil. Vases were filled with soil and Brachiaria decumbens, Digitaria horizontalis, Ipomoea nil, Ipomoea grandifolia, Bidens pilosa and Sida rhombifolia weeds were sown and then covered or not with sugarcane mulch, depending on the treatment used. The experimental design used was entirely randomized with four replications. Treatments were displaced in 4 x 2 factorial scheme, with factors representing four periods without rain occurrence, 1, 15, 30 and 60 days and two herbicides positioning, over the soil without sugarcane mulch and over sugarcane mulch. Control evaluations were carried out at 14, 28 and 42 days after rain occurrence. In general mode, it was possible to observe that flumioxazin application over the soil or over sugarcane mulch promoted control satisfactory levels of weeds. Reductions on control levels of some weed species were observed when the herbicide was exposed to a period of 60 days without rain occurrence.