Management of fungicides can affect resilience of cultivars to foliar diseases in oats

The entry and progression of oat foliar diseases affect yield potential, requiring a combination of genetic resistance and management technologies. The objective of the study is implementing a management system to reduce the use of fungicide in oats by the anticipation of the application and a longer interval from the last application to the grain harvest, together with the identification of cultivars that are more resilient to disease. The study was developed in 2018 and 2019, in soil of type Typical Dystroferric Red Latosol and Cfa (humid subtropical) climate, in Augusto Pestana, RS, Brazil. The experimental design was randomized blocks with three replications in a 23 x 5 factorial, for 23 oat cultivars and 5 conditions of fungicide use: control (no application); one application 60 days after emergence (DAE); two applications at 60 and 75 DAE; three applications at 60, 75 and 90 DAE and four applications at 60, 75, 90 and 105 DAE, with measurement of grain productivity. In oat cultivation, the early and sequential application of fungicide at 60, 75 and 90 days after emergence guarantees satisfactory productivity with a long interval from the last application to harvest for greater food security. The cultivars URS Altiva and IPR Artemis show resilience in the presence of foliar diseases in the absence and reduced use of fungicide, facilitating the transition between conventional and agroecological agriculture in oat cultivation