Management Strategies using Antagonistic Rhizobacteria against Pathogenic Fungi and Bacteria in Rice (Oryza sativa L.)

Rice (Oryza sativa L.) is the most widely cultivated cereal in more than 100 countries. The objective of this trial was to mitigate plant mortality and reduce damage to leaf area and tillers in the Anar 2021 rice variety through pathogen biocontrol and the reduction of chemical inputs. Foliar applications of biopesticides and chitosan were carried out 20 and 35 after germination. The evaluated treatments were: T1: Elemental sulfur + Pseudomonas fluorescens and Bacillus subtilis; T2: Trichoderma harzianum + Bacillus subtilis and Pseudomonas fluorescens; T3: Trichoderma harzianum + Chitosan; T4: Trichoderma harzianum and Trichoderma asperellum T5: Bacillus subtilis; and T6: Control. The evaluated variables included population density, mortality rate, incidence of Rhizoctonia solani, area under the disease progress curve (AUDPC), and tiller efficacy against Rhizoctonia solani. The analysis of variance revealed significant differences (P ≤ 0.05) among the treatments. T2 achieved the highest population density, with 517 tillers/m2 and presented the mortality rate at 4.8%, reduced the incidence and AUDPC of Rhizoctonia solani to 5% and 327% per/day at 60 days after application, respectively. Besides, showed 91.8% efficacy against Rhizoctonia solani at 60 daa. The bacterial pathogens Xanthomonas axonopodis pv. oryzae and Pseudomonas fuscovaginae have been identified.