Competição de diferentes cultivares de soja com plantas daninhas

Abstract

The experiments in substituting series allow us to study the effects of population and the proportion of plants, the importance of intraspecific and interspecific competition, and the dynamics of the resources provided by the environment. The objective of this work was to evaluate the relative competitiveness of soybean cultivars with bittergrass and vassourinha grass, in a vase condition. The experiment was carried out in the 16/17 harvest, adopting a population of 8 plants per pot, equivalent to 250 plants / m2, in proportions of 100: 00%, 75: 25%, 50: 50%, 25: 75% and 0: 100% for cultivars NS 6909, TMG 7262 and BRS 184, and weeds, bitter grass ( Digitaria insularis) and Vassourinha grass (Chloris sp.). The one used was the entirely random, with four replicates. Competitiveness analyzes were carried out through diagrams for substitutive experiments and the use of relative competitiveness indexes. The dry matter and height data of the cultivars and weeds were collected 45 days after emergence. The soybean cultivars in competition with weeds presented similar results for the dry matter, and the three evaluated were affected; being that the soybean presented greater aggressiveness in relation to the competitors. For the height variable there was no competition, however, the weed species showed heights higher than the soybean cultivars.