Herbicides doses in the defoliation of common bean to anticipate mechanized harvesting

José Geraldo Da Silva,Pedro Henrique Lopes Sarmento,Adriano Stephan Nascente

doi:10.51694/advweedsci/2021;39:00009

Abstract

Abstract Background The use of desiccant herbicides can allow the anticipation of common bean harvesting by providing a reduction in the humidity of plants and grains. Objective Determine the effect of doses of desiccant herbicides on the moisture content of the plants (stems, leaves and grains), in the 100 grains mass, grain yield and physiological quality of the seeds of two contrasting common bean cultivars. Methods The experimental design for each cultivar (BRS FC 104, super early cycle, 60 days from sowing to harvesting and BRS Estilo, normal cycle, 90 days from sowing to harvesting) as in randomized blocks in the factorial scheme 4 x 3 x 4, with four replications. Treatments consisted of four herbicides (ammonium glufosinate (200 g L-1 of active ingredient, ai), glyphosate (480 g L-1 of acid equivalent), diquat (200 g L-1 of ai) and paraquat (200 g L-1 of ai), with three doses (200 g L-1, 400 g L-1 and 600 g L-1 of ai per ha for ammonium glufosinate, diquat and paraquat, and 480 g L-1, 960 g L-1 and 1,440 g L-1 of ae per ha for glyphosate) with evaluations of the variables at 0, 3, 5 and 7 days after application of the herbicide. Results All desiccants used provided faster drying of the botanical structures allowing faster harvesting in relation to control plants. The dosage of 200 g L-1 of the ai ha1 in the cultivar BRS FC 104 and 1,440 g L-1 of ae per ha for glyphosate and 600 g L-1 of ai per ha for the others dessicants in the cultivar BRS Estilo were those that provided best plant drying. The use of desiccants in plants of common bean did not affect crop grain yield. The dosage of 600 g L-1 of ai per ha of the ammonium glufosinate desiccant provided a reduction in vigor and normal seedlings and an increase in abnormal seedlings in the cultivar BRS FC 104. Conclusion All desiccant herbicides used allowed anticipation of common bean harvesting.

Highlights

Common bean (Phaseolus vulgaris L.) is the main source of vegetable protein for direct consumption by the low-income population (Ganascini et al, 2019)
The objective of this work was to determine the effect of doses of desiccant herbicides on the moisture content of the plants, in the mass of 100 grains, grain yield and physiological quality of the seeds of two common bean cultivars
In the cultivar BRS FC 104 there was isolated effect of the days after the application of the desiccant for the moisture content in the variables stem + leaf, pods + grains, and in the whole plant, and there was no effect on the mass of 100 grains (Table 2)

Summary

Introduction

Common bean (Phaseolus vulgaris L.) is the main source of vegetable protein for direct consumption by the low-income population (Ganascini et al, 2019). The best time for harvesting common bean seeds is just after physiological maturity, a time when the seeds have high vigor, germination and maximum accumulation of dry matter (Coelho et al, 2012; Lamego et al, 2013; Santos et al, 2005). At this stage, the seeds have a high moisture content (above 40%) and the plant is still with green and moist leaves and stems. Objective: Determine the effect of doses of desiccant herbicides on the moisture content of the plants (stems, leaves and grains), in the 100 grains mass, grain yield and physiological quality of the seeds of two contrasting common bean cultivars. Conclusion: All desiccant herbicides used allowed anticipation of common bean harvesting

Objectives

Methods

Results