Conditioning and coating of Urochloa brizantha seeds associated with inoculation of Bacillus subtilis1

ABSTRACT Technological advances for improving the sowing stage of forage plants are important because, besides increasing the operation efficiency, they may also positively affect the plant growth. This study aimed to evaluate the inoculation of Bacillus subtilis in Urochloa brizantha seeds, using coating, physiological conditioning and storage procedures, as well as to observe its effects on seed storage and plant growth. A completely randomized design, in a 2 × 3 × 5 + 1 factorial scheme [two inoculation procedures (coating and conditioning), three inoculants (B. subtilis AP-3, B. subtilis PRBS-1 and without bacteria), five storage periods (0, 30, 60, 90 and 120 days) and control (bare seeds)], with five replicates, was used. Two lots of U. brizantha seeds were used, characterized as being of higher and lower viability. After the treatments, part of the seeds was employed to evaluate the plant growth promotion in a greenhouse, during 180 days, while the remaining portion was stored at a temperature of 25 ºC, with the seed germination being evaluated every 30 days, for 120 days. The physiological conditioning showed the best performance in the evaluations carried out for U. brizantha seeds with B. subtilis. The coating and conditioning of the U. brizantha seeds with lower viability, both with and without the inoculation of bacteria, increases the shoot mass of plants after 180 days of growth.