Avaliação da qualidade de sementes de algodão em função do uso de bioestimulantes no campo de produção e em tratamento de sementes

Abstract

Seed quality is determined by genetic, physical, physiological and health factors, directly influencing agricultural productivity. This study evaluated the impact of the biostimulants Stimulate® and Biozyme® on the quality of cotton seeds in the field and in treatment via physiological conditioning. The experiment was carried out in Lucas do Rio Verde – MT, with laboratory analyzes carried out at UNOESTE, in Presidente Prudente – SP. The biostimulants were applied in the field in phases V3 and B1 and, in the laboratory, by physiological conditioning. The evaluation included plant height, productivity, plume and seed yield, in addition to the quality of mature and immature seeds, using the same tests described below. The evaluation of physiological conditioning, for 24 hours at 25 °C with aeration, consisted of the following seed quality tests: germination by normal seedlings, germination by root protrusion, area under the curve of accumulated germination, average germination time, time to 20% of germination as a function of total seeds, time between 25 and 75% of maximum germination, length per seedling, length per total seed, dry mass per seedling and dry mass per total number of seeds. It was concluded that the application of biostimulants in the field resulted in an increase in the proportion of immature seeds for both products above 18% while Stimulate® also reduced productivity. Physiological conditioning with Biozyme® showed more consistent and favorable effects on hypocotyl-root lengths above 11.1 cm.pl¹ and on seedling mass when compared to Stimulate®, a value higher than 0.026 g.totsem¹. Physiological conditioning with water presented, for many variables, an effect similar to the use of biostimulants and superior to seeds not treated with physiological conditioning.