Influência de plantas de cobertura na supressão de plantas de buva em lavouras de soja

Abstract

The Conyza spp is one of the most interference weed on soy crops and its control involves the frequent use of herbicides and a good resources contribution. The intense utilization of herbicides have been causing weeds resistance at this products.Search for alternatives to decrease the Conyza spp. infestation on soy crops implies on less expensive costs to produce, on contribuition to increase the agricultural production sustainability and increase the produtivity. The purpose of this work is evaluete the capacity of diferentes species of cover plants on the suppression of Conyza spp plants on soy crops. The experiment was conducted on Pinhalzinho – SC, on a place with historical presence of Conyza spp. The treatments were: oat (60 kg/hectare), forager kale (20 kg/hectare), oat plus forager kale (30 kg/hectare + 10 kg/hectare), oat plus forager kale (20 Kg/hectare + 10 Kg/hectare) e fallow, for witness, and the outline used was DBC with 30 installments with 9 m² (3 x 3m). The valuetion constituted on the number of Conyza spp plantas during the development and thirty days after the dessecation and estimation of fresh mass per hectare and dry mass per hectare. The results were submitted to a variance analysis and compared using the Tukey test with 5% os probability. The cover plants decreased significantly the number of Conyza spp plants during the development and also after the dessecation and the quantity of fresh mass produced by the cover plants was inversely proportional to the number of Conyza spp plants during the development. The mixture of oat (20 Kg/hectare) and forrager kale (10 Kg/hectare) was the better treatment that supress the Conyza spp plants during the development. After the dessecation, the cover plants did not have statistics diferences each other, but al the cover plants were better than the fallow.