Avaliação da ação hormonal 2,4 D (ácido 2,4 D diclorofenoxiacético) em tratamento de sementes de soja (Glycine max L. Merrill)

Abstract

The soybean [Glycine max (L). Merrill] is considered one of the world's most cultivated oilseeds. Brazil stands out for having large soybean producing areas and a high productivity indexes. The goal of this study is to evaluate the development of soybean plants with different doses of 2,4-D (2,4-dichlorophenoxyacetic acid) by seed treatment, in order to verify their hormonal action. The experiment performed at the Nucleus of Research in Applied Biotechnology NBA- UEM. The experiment was implemented by an Experimental Completely Randomized Disgn, composed of five treatments with eight repetitions. The 2,4 D was used in dosages of 0.005; 0.05; 0.5; 5 and 50mL ha-¹. The appraisements were carried out at 7, 14, 21 and 28 Days After Emergency (DAE), in which the size of the aerial part was verified, the chlorophyll was analysed, as the weight of the green mass of the aerial part and the root length. The results showed that 2,4 D presents a limitation for it’s hormonal activity. Doses up to 5 mL ha-¹ caused damages in the development of the plants, however in dosages lower than 0.5 mL ha-¹, the herbicide 2,4 D presented hormonal activity allowing growth and development of soybean plants.