Barley Net Blotch (Pyrenophora teres Drechsl.) Epidemiology and Management

Abstract

Two experiments were conducted in strip-plot block design during August-December 2002 and April-August 2003 at Sinana, Southeast Oromia, Ethiopia. Vertical factor was 4 varieties of barley and horizontal factor was propiconazole treatment (12+1) and they were replicated four times. The objective of this experiment was to study net blotch epidemiology and management and to suggest the future net blotch control strategy. The level of net blotch epidemic varied by year but its onset was early at GS13, although rainfall was low and temperatures were slightly high in both experimental years. Varieties and treatments affected the course of net blotch development starting from the early stage of the crop. Difference among varieties was substantial starting about 36-44 days after planting. Disease epidemic was significantly influenced by leaf positions, being high in the lower leaves and low in the upper leaves. Net blotch severity was associated negatively with grain yield and 1000-kernel weight starting 36 days after planting. Propiconazole foliar applications at GS30&39 provided greater TKW (4-6%) and grain yield (314.8-560kg / ha) over non-fungicide treatment in present study. Seedling resistance and infected plant debris management as routine activity and propiconazole spray at GS30&39 in seed and malt barley production in severe net blotch development were suggested as future components of barley net blotch disease management strategy.