Avaliação da mancha parda e brusone no arroz (Oryza sativa L.) irrigado em função do sistema de semeadura no período chuvoso

Abstract

The culture of rice (Oryza sativa L.) is very affected by several diseases, in sowing, the rice seeds remain on the soil surface, these can become a source of inoculum for brusone and brown spot. However, studies are needed to intensify this knowledge, since it is little studied in the state of Amazonas. The present study aimed to evaluate the severity of the diseases brusone and brown spot on the leaf, grain spot and brusone on the panicle of rice submitted to different sowing systems in the rainy season. The present work was carried out in the field in the rainy season in the experimental farm of the Federal University of Amazonas - IEAA, located on the BR 319 at km 5 towards Humaitá -AM - Porto Velho - RO. The different sowing systems were evaluated; furrow sowing, incorporated sowing, non-incorporated sowing, pre-germinated sowing. In conclusion, in all treatments there was incidence and severity for both brusone and brown spot, however, some treatments showed the lowest mean incidence and severity. The treatment T6- system of sowing in normal incorporated furrow was the one that had the lowest average among the treatments, the sowing system in which the seeds are exposed on the soil surface were the ones that presented the highest averages of incidence and severity.