Preserving Spring Oat Yields in New York Through Varietal Resistance to Crown Rust

Abstract

Crown rust is the principal disease of spring oat in New York. Management with resistance genes is effective but contingent on understanding varietal responses to local pathogen populations. Field studies were conducted from 2015 to 2018 to assess the crown rust susceptibility of commercial cultivars and public breeding lines under natural conditions in New York. Three of the 10 commercial varieties trialed were determined to be resistant, and breeding lines from five different states also exhibited resistance. On average, yield was reduced by 34.56 kg/ha for every 1% increase in crown rust severity, whereas the impact on test weight was negligible. A race differential panel was deployed in 2018 at a central screening nursery to determine the range of pathogen virulence present. Susceptible interactions were observed on only five crown rust differentials, and virulence on all five has been recorded at high levels across the country. Crown rust may be a limiting factor to oat production in New York, but yield potential and crop value can be preserved by planting an appropriately resistant variety.