SILICON FERTILIZATION AND SEED MICROBIOLIZATION ON DISEASE SEVERITY AND AGRONOMIC PERFORMANCE OF UPLAND RICE ¹

EFEITO DA FERTILIZAÇÃO DE SILÍCIO E MICROBIOLIZAÇÃO DE SEMENTES SOBRE A SEVERIDADE DE DOENÇAS E DESEMPENHO AGRONÔMICO DE ARROZ DE SEQUEIRO

ABSTRACT

Rice is one of the world’s most consumed cereals, however, its production is affected by fungal diseases. Thus, the objective of this work was to evaluate the severity of diseases and grain yield potential of upland rice with silicon fertilization combined with seed microbiolization with Bacillus methylotrophicus isolates. Two experiments were conducted, one in Igarapé do Meio, Maranhão (MA), Brazil, with rice seeds of the variety Palha-Murcha and one in São Bento MA with rice seeds of the variety BRS-Primavera. A randomized block experimental design in a split-plot arrangement with five replications were used in both experiments, with agro-silicon rates (0.0, 1.0, 2.0, 4.0 and 6.0 Mg ha^-1) in the plots and microbiolized and non-microbiolized rice seeds with B. Methylotrophicus at concentration of 10⁸ CFU ml^-1 in the subplots. The seedling emergence, grain yield, number of panicles, plant height, plant dry weight and severity of brown leafspot, leaf scald and grain spot were evaluated. Soil fertilization with agro-silicon affected positively the plant height of the variety Palha-Murcha and the number of panicles, plant dry weight and grain yield of the variety BRS-Primavera, and negatively the germination of the variety BRS-Primavera. Leaf scald severity in the variety BRS-Primavera reduced with microbiolized seeds with B. methylotropicus. Microbiolization with B. methylotropicus had no effect on severity of brown leafspot and grain spot in the varieties evaluated.

Keywords:
Bacillus methylotrophicus; Agrosilicon; Biological control; Diseases; Rice production.