International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Index Copernicus Value (2013): 6.14 | Impact Factor (2014): 5.611 Volume 5 Issue 2, February 2016 www.ijsr.net Licensed Under Creative Commons Attribution CC BY Farmers’ Knowledge and Perceptions of Rice yellow mottle virus in Selected Rice Growing Areas in Tanzania Judith Hubert 1 , Ashura Luzi-Kihupi 2 , Eugénie Hébrard 3 , Herman John Faraji Lyimo 4 1, 2, 4 Sokoine University of Agriculture (SUA),Department of Crop Science and Production, P. O. Box 3005, Morogoro, Tanzania and Africa Rice Center (AfricaRice), P. O. Box 33581, Dar es Salaam, Tanzania 4 Sokoine University of Agriculture (SUA),Department of Crop Science and Production, P. O. Box 3005, Morogoro, Tanzania 3 Institut de Recherche pour le Developpment (IRD), UMR Interactions Plantes Microorganismes Environnement (IPME), BP 64501, 34394 Montpellier Cedex 5, France Abstract: Surveys were conducted in eight rice growing regions of Tanzania, namely; Morogoro, Pwani, Arusha, Kilimanjaro,Shinyanga, Kigoma, Mbeyaand Rukwa regions, to determine farmers’ field practices, knowledge and perceptions onRice 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 fieldsusing 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 (P≤0.05)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 farmersindicated 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. Keywords: Farmers’knowledge, Rice yellow mottle virusprevalence, Management 1. Introduction Rice yellow mottle virus (RYMV) belongs to the genus Sobemovirus.It is a variable, widespread and highly infectious rice (Oryza sativa L.) pathogen in Africa [1],[15]. It was first observed in 1966 in Kenya [4] and later reported in nearly all rice-growing countries of Sub-Saharan Africa [2]. In Tanzania mainland, the first incidence of the virus was reported in 1993 in Mkindo, Morogoro region[12]. Since then, the disease has been reported almost in all the rice growing areas of Tanzania. Rice yellow mottle virus is a variable and very serious disease in Tanzania. The disease has different local names (Fagia, Kimyanga, Kimbwengu, Kinasa, Mbekese - means a rice plant killer) depending on locality. It is now known to occur in almost all irrigated and rain-fed (flooded) lowland rice producing agro-ecologies in Africa [9]. The virus is readily transmitted when the sap of infected leaves come in contact with healthy leaves either through mechanical injuries or through insect vectors. Wind, mammals such as cows, donkeys and rats are also agents of dispersal of RYMV [29]. The disease is characterized by mottling and yellowing symptoms, stunted growth, reduction of tiller formation and grain sterility. In severe cases, infected plants may die. However, symptoms are not always enough to identify the disease. The ELISA techniques using antibodies is recommended in order to ascertain the presence of the virus in infected rice plants. Most rice cultivars, especially those of the Oryza sativaindica species are susceptible to RYMV. Farmers in developing countries have been using their own knowledge in managing plant diseases [5]. However, the information on farmers’ knowledge and perceptions of RYMV disease in Tanzania is limited and farmers’ disease management is often ineffective. Such knowledge requires proper document for improvement purposes. Selener[24] documented the advantages of involving farmers in research, extension and development efforts. Collaboration of farmers with the formal research sector may offer researchers a mechanism to ensure that their work is relevant to farmers’ needs and conditions [11]. Rhoades and Booth [22] reported that, the involvement of farmers in the research process has increased the chance of success in the generation of appropriate agricultural technology. Participatory plant breeding has been shown to be an effective way to select locally adapted rice genotypes and to improve farmers’ access to useful crop genetic diversity [11],[26],[31]. Rice farmers continue to count losses due to RYMV disease. The disease is a major problem in rice production in Paper ID: NOV161219 549