Inoculação com Bacillus subtilis, Bacillus megaterium, Rhizobium tropici e Trichoderma harzianum em sementes de feijão

Abstract

Beans are one of the most common legumes on the Brazilian table, with an important nutritional and social role in the country. In order to reduce the use of chemical fertilizers in the crop, inoculation and coinoculation of microorganisms is a strategy that has been gaining ground in recent years. In this sense, the objective of this work was to evaluate the performance of the inoculation and coinoculation of bean seeds with strains of bacteria Bacillus subtilis and Bacillus megaterium, Rhizobium tropici and Trichoderma harzianum in the development and productivity of culture. For this purpose, this experiment was divided into three parts, firstly, a germination test was carried out in the laboratory, according to the methodology proposed by the Seed Analysis Rule; subsequently, an experiment was carried out in pots, using a randomized block design (DBC) with five treatments (T1 - control; T2 - inoculation with R. tropici; T3 - inoculation with T. harzianum; T4 - inoculation with B. subtilis and B. megaterium; T5 - coinoculation with T. harzianum, R. tropici, B. subtilis and B. megaterium) and four replications; and, using the same design, a field experiment was carried out. The products were inoculated according to the manufacturer's recommendations at the time of sowing, and the cultivar used was the IPR Urutau. The percentage of normal, abnormal and dead seedlings, fresh and dry mass of roots and shoots, mass of a thousand grains and grain yield were determined. The data obtained in the three parts of this experiment were submitted to analysis of variance and, when significant, submitted to the Scott Knott mean test at 5% significance level. It was verified that the use of the association of microorganisms (T5) provided a higher percentage of normal seedlings and increments in the agronomic components of the bean crop, culminating in an increase in grain productivity. Therefore, coinoculation of T. harzianum, R. tropici, B. subtilis and B. megaterium proved to be viable under the conditions studied.