Farmer knowledge of bacterial wilt and root-knot nematodes and practices to control the pathogens in high tunnel tomato production in the tropics

Sustainable production of tomato (Solanum lycopersicum L.) under high tunnels is threatened by bacterial wilt (caused by Ralstonia solanacearum) and root-knot nematode (Meloidogyne spp.). Knowledge was generated about the concomitant occurrence of these diseases from January to September 2016, and knowledge and experience of farmers about practices to control them were investigated. The study involved a survey during which 32 farmer groups in 6 subcounties of Kiambu County, Kenya, were interviewed. About 78.1% of high tunnels were in use for 1–2 years and 62.5% of farmers taking part in the study could identify symptoms caused by both causal organisms, which resulted in crop loss of 50%–100%. Seventy-one percent of respondents had positive feelings about high tunnel tomato production. About 82.6% had the soil in which they produced tomato in the tunnels analyzed for nutrition and presence of pathologens, but the majority (71.7%) never followed recommendations on how to amend their soils nutritionally and against the major soil-borne diseases. These findings indicate that more research and information are required so that farmers can optimize high tunnel production of tomato under tropical conditions.