Occurrence of Clubroot Disease and Farmers’ Knowledge on its Management in Cabbage Growing Areas of Morogoro, Tanzania

Abstract

disease caused by Plasmodiophora brassicae (Woronin) is recently one of the most economically important diseases of Brassica vegetable crops. It causes more than 10 -15% yield losses of cabbage in the world. A survey was conducted in August, 2018 to investigate farmers’ awareness of cabbage clubroot disease and assess its occurrence in cabbage fields at Mgeta Ward in Mvomero District, Morogoro, Tanzania. Mgeta Ward was purposely selected based on its intensive cabbage production and farmers concern on occurrences of clubroot disease. About 23 cabbage fields were surveyed for assessment of cabbage clubroot disease and 120 farmers were interviewed on indigenous knowledge on clubroot disease management and other pests of cabbage. Results showed that the level of education among the respondents was low as majority (95.5%) of farmers had primary education. Based on colored photograph of clubroot infested cabbage plant, a total of 88.3% of farmers interviewed reported the presence of the disease in their fields. Some farmers have been using several clubroot management options. Clubroot disease management options mentioned by farmers were such as crop rotation (33.7%), application of sulphate of ammonia fertilizer (5.0%), a combination of crop rotation and ashes during transplanting (3.7%), early maturing varieties (3.4%), a combination of crop rotation and using early maturing varieties (3.3%), early maturing varieties and crop rotation (0.9%), transplanting cabbage seedlings after adding ashes and later irrigate the fields until they are water logged (0.3%). However, 49.7% of the interviewed farmers had not used any means of controlling clubroot disease in their fields. Generally, the average disease incidence in all surveyed cabbage fields was 31.7%. Cultural practices are the only reliable management option since there is no currently fungicides recommended for clubroot management.

Keywords: Plasmodiophora brassicae, survey, pests, disease control