Genetic Improvement in Minnesota‐Adapted Oat Cultivars Released Since 19231

Abstract

Increased crop yields over the past 50 to 100 years have been attributed to new cuitivars and improved cultural and management practices. Documentation of the contribution of plant breeding to oat (Avena sativa L.) yield improvement may provide insights into the optimum strategy for attaining further gains. Our objective was to quantify genetic improvements in grain yield, kernel quality, and associated agronomic and physiological traits of oat cultivars grown in Minnesota over the past six decades. Nine cultivars released since 1923 were grown in field experiments at St. Paul, Minn. in 1979 to 1981. Mean grain yield over all years ranged from 20.0 q/ha for ‘Anthony’, to 31.3 q/ha for ‘Moore’. Based on the mean yield of ‘Gopher’, the annual rate of increase since 1923 was 0.8%. Newer cultivars generally lodged less than older cultivars, which may also contribute to the increases in harvestable grain yield obtained in commercial fields today. Cultivars differed in groat percentage, but no trend with time of release was evident. The collective improvement in both grain yield and, to a lesser extent, groat percentage, resulted in an annual rate of increase in groat yield of 0.9%, slightly higher than that for grain yield. Kernel weight has increased over time, while the number of kernels per unit area has generally decreased. Newer cultivars thus reflect the emphasis that has often been placed on selection for yield and kernel quality and size. Biological yield, harvest index, total N (in groats plus straw), groat N, and N harvest index (NHI) were all greater newer cultivars, linearly related to cultivar age, and positively correlated with grain yield. Higher groat protein yield of modern cultivars was primarily a reflection of the gains in groat yield and improvement in NHI or N partitioning.