Management of ufra disease of rice caused by Ditylenchus angustus with nematicides and resistance

Abstract

The effects of nematicide application timing and type on the management of ufra disease of rice caused by Ditylenchus angustus were investigated in the rain-fed and irrigated rice ecosystems. A broad range of rice (Oryza sativa L.) genotypes were also screened for resistance to D. angustus. Ufra infestation was significantly reduced when 1 kg ai/ha furadan 5G was applied up to 20 d before transplanting of infested seedlings in the field. Three granular nematicides, sunfuran 5G, edfuran 5G and forwafuran 5G, all applied at 1 kg ai/ha were evaluated against ufra in comparison with 1 kg ai/ha furadan 5G and a non-treated control. In both the ecosystems, all the 3 nematicides significantly reduced the number of damaged-tillers and total ufra infestation compared to the non-treated control. Similarly, sunfuran 5G, edfuran 5G, and forwafuran 5G treated plots had 45.3 to 52.7% healthy panicles with 3.89 to 4.02 t/ha yield in rain-fed rice and 47.6 to 53.0% healthy panicles with 3.85 to 3.97 t/ha yield in rain-fed and irrigated rice, respectively. These yields were similar to furadan-treated rice in 2 ecosystems. Yield losses due to ufra disease were 49.1 and 42.4% in the rain-fed and irrigated rice, respectively. Soil application of the nematicides, forwafuran, edfuran and sunfuran was cost-effective especially in fields of endemic areas. A total of 53 rice entries were tested, only 4 entries, fukuhonami, hyakikari, akiyu taka and matsuhonami showed highly resistance reactions to D. angustus. Key words: Cost-effective, Ditylenchus angustus, management, nematicides, rice ufra disease, resistance reaction.