Physiological traits of Crambe abyssinica under herbicide application

Abstract

The cultivation of Crambe abyssinica is relatively recent in Brazil, and crop management data aiming to high yields with minimal economic and environmental risk is scarce. We aimed with this study to evaluate the effect of herbicides at varying doses on physiological traits. The experiment was installed in completely randomized blocks design with four replications, in factorial scheme 5x4+1, being factor A the five herbicides and factor B its doses, plus a control treatment with no herbicide. The following herbicides and doses were tested: fluazifop-p-butyl 0,25; 0,75; 1,0 e 1,5 L ha^-1; clethodim 0,1; 0,3; 0,4 e 0,6 L ha^-1; bentazon+imazamox 0,25; 0,75; 1,0 e 1,5 L ha^-1; s-metolachlor 0,38; 1,13; 1,5 e 2,25 L ha^-1; and sethoxydim 0,25; 0,75; 1,0 e 1,5 L ha^-1. Crop plants presented differential behaviour to herbicides, causing all crop injuries at some degree; bentazon+imazamox promoted plant death at the label dose. Fluazifop-p-butyl, s-metolachlor and sethoxydim promoted great reductions in photosynthesis rate at the highest doses; on the other hand, water use efficiency was reduced by all herbicides.