Farmers? Knowledge and Perceptions of Rice yellow mottle virus in Selected Rice Growing Areas in Tanzania

Surveys were conducted in eight rice growing regions of Tanzania, namely, Morogoro, Pwani, Arusha, Kilimanjaro, Shinyanga, Kigoma, Mbeya and Rukwa regions, to determine farmers field practices, knowledge and perceptions on Rice yellow mottle virus (RYMV). The study also examined challenges faced by rice farmers due to RYMV in order to ascertain the proper disease management approach. Rice yellow mottle virus disease was assessed in the fields using quadrats of 1 m x 1 m. Symptoms of RYMV and Direct Antibody Sandwich - Enzyme-linked Immunosorbent Assay (DAS-ELISA) were used for disease diagnosis. A total of 126 samples tested positive for RYMV with polyclonal antiserum. Rice farmers were allowed to narrate problems, setbacks and achievements encountered in rice production in relation with RYMV. The lowest RYMV disease prevalence (25 %) and severity (25 %) of the disease were recorded in Shinyanga region, while the highest prevalence (82 %) and severity (55 %) were recorded in Morogoro region. Most of the farmers interviewed (91 %) cultivated their own saved rice seeds while very few farmers (5 %) were purchasing improved seed and only 4 % received seeds from district council via agriculture extension officers. Forty five (45 %) of farmers used the broadcasting method to plant rice seeds while 55 % established nurseries and transplanted rice seedlings 14 -21 days after sowing. There was a positive correlation (P0.05) between weeding method, source of seed, line spacing and occurrence (but not prevalence) of RYMV disease. The majority of farmers interviewed weeded once per crop season and about 80 % used a hand hoe, while 20 % used herbicides. All farmers indicated that RYMV disease occurred each season at different incidences depending on variety grown. Thirty two percent of farmers indicated that the existence of RYMV disease over the past five years was due to local rice cultivars they used. The findings indicate that RYMV disease remains a major problem in rice production in Tanzania. There is thus, a need for capacity building of rice farmers on management of RYMV in the country.