The 2,3,5-triiodobenzoic acid, an auxin transport inhibitor, when applied on leaves can reduce the vegetative growth. One of the problems faced by soybean producers is the lodging of the plants in the field due to excessive vegetative growth. Trying to evaluate the effects of TIBA over soybean (Glycine max (L.) Merrill cv. Pintado) vegetative growth and yield, an experiment was carried out in the greenhouse of the Department of Biological Sciences at ESALQ/USP. Using potted-plants, TIBA was sprayed on the leaves of soybean plants at 30, 40 and 50 g L-1, at V5 phenological stage. Plant height, number and mass of pods per plant and 100-grain mass were assessed. The experiment was completely randomized with 4 treatments and 6 replications. Data were submitted to variance analysis and polynomial regression. TIBA was effective in reducing plant height, without affecting parameters related to production.
plant regulator; vegetative growth; pod-set; auxin inhibitor
