Effect of stubble management, tillage and cropping sequence on the severity of take-all and eyespot diseases of wheat

Abstract

Bread wheat (Triticum aestivum L. em Thell) is affected by several soil- and stubble-borne diseases in Ethiopia, including take-all and eyespot, which often necessitate instituting control. In this study, the efect of stubble management, tillage and cropping sequence on the severity of these diseases was investigated. Four multi-factor crop management trials were initiated in 1992 at two research sites in the south-eastern highlands of Ethiopia. Two trials were established at each site: one based on tractor and the other on ox-plough tillage. A three year rotation, consisting of two consecutive crops of wheat following one crop of faba bean, reduced the severity of take-all, but had little effect on eyespot severity. Conservation tillage decreased take-all severity relative to conventional tillage, but had no effect on eyespot severity. Stubble burning did not exhibit a consistent effect on the severity of either disease. However, full stubble retention relative to partial removal increased eyespot severity. The interactions among the three crop management factors were seldom significant for either disease. Rotation of wheat with faba bean should be recommended as a means of minimising take-all severity. The adoption of conservation tillage practices for wheat production in Ethiopia should not be hindered for fear of spreading these specific trash-borne diseases, although, full stubble retention could increase the severity of eyespot.