THE EFFECTS OF ALTERNATE CROP MANAGEMENT PRACTICES ON TAKE-ALL AND EYESPOT DISEASES OF BREAD WHEAT IN SOUTHEASTERN ETHIOPIA

摘要

Bread wheat (Triticum aestivum) production is adversely affected by several diseases in Ethiopia, including take-all (Gaeumannomyces graminis var trifici) and eyespot (Pseudocercosporella herpotrichoides). The increasing incidence of these diseases may necessitate changes in farmers' agronomic practices to facilitate control, considering the yield losses they incur. Several experiments were conducted from 1992-1994 in Arsi Region of Ethiopia to assess the effects of crop rotation, continuous application of N and P fertilizer, stubble management, and tillage practice on take-all and eyespot diseases. Rotation of wheat with dicot crops in a 2 year cycle significantly reduced both diseases. Application of N and P fertilizer increased eyespot incidence.Stubble burning consistently controlled eyespot without having any evident impact on take-all. Reduced tillage decreased take-all incidence relative to the conventional practice. Significant interaction effects were observed for two or more of the management factors studied. Rotation of wheat with dicot crops should be considered as an important means of controlling both take-all and eyespot. Despite its potential for long-term detrimental effects on soil health, stubble burning exhibited good controlof eyespot.