Defoliation at different vegetative stages and assessment of morphological and yield components

Abstract

Objective was to evaluate the influence of defoliation of a soybean cultivar indeterminate growth in different vegetative stages on morphological characters and yield components. The study was conducted in the years 2010/11 and 2011/12. The experimental design was a randomized block design with seven treatments and four replications for each year. The treatments were: T1: No defoliation; T2: Defoliation in V4, T3: Defoliation in V4 and V5, T4: Defoliation in V4, V5 and V6, T5: Defoliation in V4, V5, V6 and V7, T6: Defoliation in V4, V5, V6, V7 and V8 and T7: Defoliation in V4, V5, V6, V7, V8 and V9. The variables analyzed were: main stem height, number and length of branches, first pod, number of pods per node on the main stem, and the branches per plant, number of reproductive nodes on the main stem, the branches, number of us total on the main stem, the branches, distance between us and grain yield. Grazing did not influence most of the morphological characters and increments the number of pods on the stem in years with good water availability and high levels of defoliation, and yield of soybean.