Seleção de bactérias promotoras de crescimento e inoculação em morangueiro

Abstract

Plant growth-promoting bacteria have been detached mainly due to their potential reducing use of fertilizers and pesticides in the production due to the capacity of stimulating the plant growth by nitrogen fixation and production of hormones. The proposed work has aimed to verify the potential of growth-promoting of 25 strains from Agricultural Microbiology Culture Collection of Federal University of Lavras, through tests of nitrogen fixation and indoleacetic acid (IAA) production. Thus, the three strains that perform the best results were inoculated in roots of strawberry seedlings (cultivar Aromas), in greenhouse condition, where the plant-growth were evaluated and the endophytic microorganisms isolation of the inoculated plants were realized. The experiment was installed in Completely Randomized Design in factorial scheme 8 × 2, where 8 bacteria levels with the following combinations: lonely, in combinatorial pairs, all three and without bacterium, and two fertilization levels (0 and 50% of nitrogen), totalizing 16 treatments with 8 repetitions for each. After 75 days, measures such as root length (RL), root dry mass (RDM), aerial part length (APL), aerial part dry mass (APDM), the number of leaves (FN) and total dry mass (TDM) were evaluated. The results show that the culture of strawberry has answered positively the inoculation of all three bacteria (Ab-V5 Azospirillum brasilense + CCMA 0056 Burkholderia cepacia + CCMA 1285 Enterobacter cloacae) in relation to non inoculated controls, is that the best result was the combination of three bacteria with fertilization of 50% nitrogen per cumulative dry mass of aerial part and root.