Co-utilization of Bacillus subtilis and flutolanil in controlling sharp eye spot of wheat by seed dressing

Co-utilization of flutolanil and endospore powder of Bacillus subtilis NJ-18 strain (109 cfu/g) was evaluated in controlling sharp eye spot of wheat(Rhizoctonia cerealis)by seed dressing.The results showed that the average EC50 value of flutolanil against R.cerealis was (0.34±0.06) μg/mL,and inhibitive mycelial growth rate of B.subtilis NJ-18 strain against R. cerealis was 96.38% and 93.97% when culture solution(108cfu/mL) and their filtrates of NJ-18 strain were diluted by 1 000 times,respectively.Flutolanil showed excellent compatibility with NJ-18 because flutolanil did not inhibit the growth of vegetable cell and endospore of NJ-18,even though the fungicide was mixed with NJ-18 and stored for 90 days at room temperature.In greenhouse,the mixture of flutolanil and NJ-18 at two ratios,i.e.,NJ-18 300 g+flutolanil(20% WP) 50 g and NJ-18 300 g+flutolanil(20% WP) 100 g were applied respectively to coat 100 kg wheat seeds,and 47.96% and 64.98% control efficacy on wheat sharp eye spot was observed respectively,when investigated at jointing stage,which was significantly higher than that of the single component.In field trial,both control efficacy and wheat thousand kernel weights of the mixture seed dressing treatments increased significantly.The treatment of mixture of 300 g NJ-18 and 200 g flutolanil (20% WP) provided control efficacy of 74.83% when investigated at jointing stage in field.The mixed/single dressing treatments of flutolanil and endospore powder of B.subtilis NJ-18 strain were proved to be safe for wheat growth.