Potato bacterial wilt management in the Central Highlands of Ethiopia

Abstract

In Ethiopia, bacterial wilt caused by Ralstonia solanacearumis the major threat to potato production. Farmers are not aware of the causes of potato diseases and they believe that all types of diseases are caused by rain and mist. Research has been carried out in four districts namely Shashemene, Tulubolo, Welmera and Welisso f rom 2011 to 2012 main crop seasons however; the research was extended to 2014 in Shashemene district. The purposes of the research was to change the perception of farmers and address the causes, sources and management options of the disease and assist farmers to develop healthy potato farms; Farmers field school(FFS) extension approach supported by sessions harmonized with crop henology was used to assess the effect of one season rotation (Potato - Beans - Potato; Potato - Cabbage - Potato; Potato - Carrot - Potato and Potato - Potato - Potato)and two seasons rotations (Potato - Beans - Carrot - Potato; Potato - Beans - Cabbage -Potato; Potato - Beans - Beans - potato; Potato - Carrot - Carrot - Potato; Potato - Cabbage - Carrot -Potato; Potato - Cabbage - Cabbage - Potato and Potato - potato - potato - potato) with none host crop species on the development of the disease. At the inception of the project, all members of the group were introduced to potato diseases and their causal agents through farmers field school extension approach. After subsequent sessions, experimentation, and demonstration at field level, more than 65 % of the farmers in the group were able to identify symptoms, causative agents and means of dissemination and possible management measures of potato wilt, late blight and viruses. The result showed that, the extension approach was found to be effective in stimulating farmer’s perception by considering their goals in the targeting and design of innovations. One season rotation of potato with beans cabbage and carrot significantly (P<0.05) reduced the incidence of the disease by 22.1, 15.4 and 27.3% respectively as compared to the mono crop potato which had 45.2 % incidence. The correlation between mean tuber yield over disease incidence in one season and two seasons rotation shad negative and significant Y= - 0.2588x + 29.767(R2= 0.7946) and Y= -0.177x + 28.019 (R² = 0.4597) respectively. Potato - Cabbage-Cabbage-Potato and Potato - Cabbage-Carrot-Potato had
significantly (p<0.05) lowest disease incidence compared to Potato – Beans– Beans- Potato, Potato - Carrot- Carrot- Potato, Potato - Carrot– Beans- Potato and Potato - Cabbage– Beans- Potato rotation however, all treatments significantly (P<0.05) reduced the incidence of the disease and increased marketable tuber yield compared to the mono crop potato. The result of these researches suggested that FFS through session supported extension approach was found to be effective to generate and disseminate bacterial wilt management technologies. One and two season rotation with beans and cabbage reduced wilt incidence, latent infection in tubers and increased tuber yield under Shashemene condition.