Ação de bioestimulante na germinação de sementes, vigor de plântulas e crescimento do algodoeiro

Abstract

The objective of this study was to evaluate different concentrations of vegetal biostimulant “Stimulate® (0.009% of citocinine, 0.005% of gibberelic acid and 0.005 of indolbutyric acid) applied through seeds, at concentrations of 3.5; 7.0; 10.5; 14.0; 17.5 and 21.0 ml / 0.5 kg of seeds and as a control 10.5 ml of distilled water / 0.5, observing its real advantages in seed germination, seedling vigor, growth and development of cotton plant. The study was carried out in a laboratory and greenhouse, evaluating germination percentage; normal seedling percentage; root length; length and dry mass of seedling 4 days after sowing; percentage of seedling emergence in sand and black earth 4 and 7 days after sowing respectively, height and dry mass of plants; number of leaves and foliar area 40 days after sowing, dry mass of root, aerial and total part of plants 16 days after sowing; rate of vertical root growth and the vertical root growth of plants in rizotron conditions. The results were submitted to regression analysis. Stimulate® affected significantly the root growth as well as the total growth, emergence percentage, and the dry mass of seedlings; the height, foliar area, dry mass of root, aerial part of plants as well as the total part of plants; rate of vertical root growth and vertical root growth, in reference to the control. The application of biostimulant on seeds reduced the dry mass of plant stems. Concentrations higher than 6.5 ml of Stimulate® / 0.5 kg in seeds reduced the rate of vertical root growth. The utilization of rizotrons provided quick, easy and successive evaluations of the cotton plant root system.