Some effects of stripe rust infection in wheats with adult plant resistance

Abstract

Effects of early and full season epidemics by stripe rust (Puccinia striiformis f. sp. Tritici) were examined in 12 wheat cultivars with different levels of adult plant resistance (APR). The APR in Cook, Bass, Banks, Kite, and Suneca was generally effective in preventing detectable yield losses due to stripe rust infection. Cultivars with lower levels of APR experienced yield losses of 15-25%, compared with 45-50% reduction for the susceptible cultivar Teal. Severe stripe rust infection early in the season, prior to node formation, resulted in significant yield reductions only in the more susceptible cultivars. Yield reductions were usually associated with reduced grain weight, and no reduction in tillering was detected in diseased plants. Severe stripe rust infection did not significantly affect the concentration of grain phosphorus, but did result in reduced grain nitrogen concentration in the more susceptible cultivars.