EthJBD – Vol 4 – No 1

The existence of a high degree of variability in crop genetic resources for disease resistance can be taken as one of the strategies that allow crops to survive in equilibrium with the challenges posed by pathogenic organisms. Three hundred twenty barley (Hordeum vulgare L.) lines were evaluated for severity and area under disease progress curve (AUDPC) at two locations in Ethiopia. These disease resistance traits were for barley leaf scald (Rhynchosporium commune) and powdery mildew (Blumeria graminis). The lines were tested during the 2017/18 and 2018/19 cropping seasons for disease severity and in a single season for AUDPC, under natural infestation conditions. The REML analysis based on BLUP mean revealed that lines differ significantly (p≤0.01) for both disease severity and AUDPC in both diseases. Furthermore, there was a significant difference (p≤0.01) among the test environments for disease severity based on over years combined data. For leaf scald, the severity was found to be higher in the first year possibly due to a comparatively earlier planting date in the season which in turn facilitated repeated infection within the growing season. Hence, apart from the utilization of resistant lines, avoiding early planting can be taken as a good management strategy to reduce the damage caused by leaf scald. Lines HB-42 and Accn# 243209 were in the top ten for both leaf scald and powdery mildew resistance suggesting their potential for multiple disease resistance. These two lines can be used as parental lines in the attempt to develop high-yielding genotypes with multiple disease-resistance backgrounds.

Keywords: AUDPC, disease severity, genetic resources, farmers’ varieties.