Habilidade competitiva da cultura da canola (brassica napus l. var. oleífera) na presença de ervilhaca (vicia sp.)

Abstract

In the cultivation of canola (Brassica napus L. Var. Oleifera) it is observed that several factors that limit their productivity, among which we can highlight the competition exerted by weeds. One of the species occurring in southern Brazil and that can become a weed difficult to control during periods of winter and spring is the vetch (Vicia sp.). With this, an experiment was conducted, in the field, in order to evaluate the competitive ability of canola cultivar Hyola 571, in coexistence with vetch. Treatments consisted in conducting control at different times of the vetch (10, 20, 30 and 40 days after emergence of canola), and the competition of free witness and treatment that competed culture with weed throughout the production cycle. The plots were arranged randomly in a randomized block design with four replications. The variables of canola were quantified: shoot dry mass, diameter and chlorophyll content at flowering, and at harvest time number of siliques, grains per pod, number of branches (primary, secondary and total) and productivity. Vetch were analyzed the dry matter of shoot every treatment, and two more times, at flowering and at the end of the canola cycle. It was observed that vetch produced a significant dry mass of the shoots, even competing, which demonstrates the high ability of competitive species, which causes a negative interference in the productivity of canola grains. The competition makes canola produce fewer branches and less siliques per plant. The number of grains per pod did not change. The total chlorophyll content and dry matter of shoot of canola were lower where there was competition. The diameter of the canola plant has been compromised, leaving the crop susceptible to lodging.