This study evaluates the sanitary quality of rice seeds cultivar Bonança, quantifies the transmission of Curvularia lunata associated with seeds - seedling and evaluates the efficiency of Bacillus spp. isolates for the control of leaf spot. The samples were disinfected and plated, and seed health was evaluated after seven days. After confirmation of pathogenicity, the seedlings inoculated by the spraying method and the occurrence of disease was assessed after seven days. For characterization of the C. lunata isolate, width and length measurements and number of septa of 100 conidia were taken. We assessed transmission rate of C. lunata in 12 trays, each with 100 seeds, and conducted evaluations at 7, 14, 21 days after infection. From each of the 100 seedlings we separated the primary root, the stem and glumes and plated them on PDA for evaluation after seven days. The inoculation of Bacillus isolates was carried out throughaerial spraying of the suspension on the plants. After one week, C. lunata was inoculated and after 15 days lesion dimensions were measured. We detected the highest incidence of C. lunata (70%), which was pathogenic to the rice variety Bonança and was detected in all organs of the seedling. Among the isolates of Bacillus, those that stood out in controlling C. lunata were B41 (B. Cereus) and B35 (Bacillus sp.), confirming their potential for biocontrol.
Oryza Sativa; biocontrol; pathogen transmission
