Abstract

Growth promoting rhizobacteria may increase the yield of some crops. Several microbial products that stimulate plant growth have been marketed. Therefore, the objective of this study was to evaluate the effect of bacteria from Bacillus genera on the production of commercial carrot roots (Daucus carota L.) in field conditions. The following isolates: SF 264 (Bacillus spp.), SF 268 (Bacillus spp.) and commercial formulations based on SF 202 (Rizos®, B. subtilis), SF 266 (Quartz®, B. methylotrophicus) and SF 267 (Onix®, B. methylotrophicus) were evaluated in four experiments conducted in commercial fields of carrot production in the municipality of Rio Paranaíba, Minas Gerais - Brazil. Each plot was 6 m long and 1.75 m wide (10.5 m2) including four double rows. An additional treatment containing only water was the control treatment. The experiment was designed as randomized blocks with five replications. The products Rizos®, Quartz® and Onix® containing Bacillus spp. increased the production of commercial carrots roots of all cultivars and sites. The SF 268 and SF 264 isolates were efficient only in two and three experiments, respectively.

Key words: Daucus carota, rhizobacteria, plant growth, Bacillus.