Eficácia de isoxaflutole no controle de plantas daninhas na cultura da batata

Abstract

This experiment was carried out at Bayer CropScience Experimental Station, in Paulinia, SP, Brazil, in a loamy soil cultivated with potato cv. Monalisa, during the 2002 growing season. The objectives were to evaluate the efficacy of isoxaflutole in weed control, to verify its selectivity to the potato crop and its effect on tubercule yield. The experimental design was a completely randomized block with seven treatments and four replications. The experimental plots consisted offour 7 m rows, with plants spaced in 0.60 m. The treatments were: controls (weedy and weedfree) and isoxaflutole rates (0.075, 0.150 and 0.300 kg/ha). Metribuzin (0.720 kg/ha) and linuron + metribuzin (0.910 + 0.384 kglha) were used as standards. The evaluations of the percentage ofweed control and the selectivity on the potato crop were carried out at 14, 28 and 42 days after treatment adopting a scale in which zero meant no weed control or no crop damage and one hundred corresponded to total control or death of the crop. The main weed species presented in the area were: Digitaria horizontalis Willd., Brachiaria plantaginea (Link.) Hitch, Gali nsoga parviflora Cav., Raphanus raphanistrum L. and Amaranthu s viridis L.. Potato plants did not show any visual symptoms of damage attributed to herbicide treatment. The species weed were efficiently controlled with isoxaflutole but there was no significant difference wheri compared with metribuzin. The treatments with isoxaflutole provided better control than linuron + metribuzin on grasses. Isoxaflutole did not affect the tubercule yield.