Control of rice bakanae disease by seed dressing with mixed solution of fludioxonil, metalaxyl-M and azoxystrobin

Abstract

Rice bakanae disease is a typical seed-borne disease caused by Fusarium fujikuroi that occurs in seedling beds and in fields. Fungicide seed treatment is an effective solution to this disease. In this study, we used a triple-fungicide suspension identified as 11% FMA, which is composed of 1.1% fludioxonil, 3.3% metalaxyl-M and 6.6% azoxystrobin to coat rice seeds for the prevention of bakanae disease. 11% FMA is water-logging resistant for rice seed treatment. Results showed that the mycelial growth of F. fujikuroi was significantly inhibited by 11% FMA in the laboratory test. Seed dressing with FMA at the rate of 1, 2, and 4 g per kg of seeds promoted seed germination and growth of seedling roots. Treatment with 11% FMA under all dose rates prevented rice bakanae disease of seedlings by more than 90%, especially by more than 95% at 4, 6 and 8 g per kg of seeds. During the subsequent maturation period, rice bakanae control efficiency reaches above 95% as well at 6 or 8 g per kg of seeds, slightly larger than about 92% at 1 or 2 g per kg of seeds. Above all, the rice yield notably improved by 11% with 1 g/kg, by around 8% with 2, 4, or 8 g/kg and by 5% with 6 g/kg treatment.