MANAGEMENT OF BAKANAE DISEASE OF RICE

Bakanae disease is widely distributed in all rice growing areas of the world. In Bangladesh, it is one of the major diseases of rice. Four methods were tested for management of this disease, of which, roguing proved ineffective in a field investigation. Among the 15 fungicides tested in vitro, all of them were found effective in various degrees against the pathogen of the disease. Best effective 4 were selected for seed treatment and know (50% carbendazim WP) was the most effective followed by folicur (25% Tebuconazole EC), protaf (25% Propiconazole EC) and celest extra (2.5% Fludioxonil and 2.5% Difenoconazole EC). In the field, foliar spray of folicur, knowin and protaf was found ineffective to control bakanae disease. Looking for resistant one, 46 BRRI released varieties, “Purbachi”a Chinese variety and 40 landraces of BRRI germplasm were tested in vitro against the pathogen. All these varieties and landraces were susceptible to the test pathogen in various degrees. Among the released varieties lower susceptibility were found in BR 23 and BR 11. Whereas, among the varieties and landraces the lowest was found in A23. Therefore, A23 may be suitable for use in the development of varieties resistant to bakanae rice disease. Introduction Bakanae is widely distributed rice disease in all rice growing areas of the world caused by Fusarium moniliforme Sheldon (Ou 1985). In many parts of South-East Asia, it is also a very common cause for yield loss. Bakanae alone caused 15.4% yield loss in Assam (Rathaiah et al. 1991) and 3.7-14.7% in Thailand (Ou 1985). It was found in the field that almost all cultivated rice varieties in Bangladesh are more or less susceptible to bakanae disease and up to 10.85% grain yield loss due to the disease was estimated (Hossain et al. 2011). The ultimate goal of all phytopathological studies is to control plant diseases and reduce yield losses. Uncontrolled plant diseases may result in less food and higher food price, or even food of poorer quality. Various ways can be implemented to control this disease like rouging, use of fungicides, and/or planting disease resistant varieties. Roguing is a traditional cultural practice. In this cultural practice, conscious farmers carefully remove and destroy infected plant or plant parts from their fields to reduce inoculum ‘foci’. Roguing is employed in such diseases as loose smut of wheat, loose and cover smut of maize, red rot of sugarcane, ergot of bajra and many viral diseases (Mehrotra 2000). Various workers in different countries of the world evaluated the efficacy of various fungicides against Fusarium moniliforme, the causal agent of the disease, under laboratory and field conditions (Aurangzeb et al. 1998, Tateishi and Chida 2000 and Gumustekin and Akn 2001). All these fungicides are not available in Bangladesh. Moreover, same fungicide may exhibit different effects against different isolates of F. moniliforme. The best way of disease control is to grow disease resistant varieties because it is the economic and environmentally safe method of ‘crop disease management’ strategies. Unfortunately, very few reports on resistance against bakanae have appeared in the literature. Considering the importance of this disease in Bangladeshi context, this research project was undertaken to generate detailed information on the management of this disease. *Author for correspondence: . Department of Botany, Jagannath University, Dhaka, Bangladesh. Plant Pathology Division, BRRI, Gazipur, Bangladesh.