M. N. KAZEMPOUR and S. A. ELAHINIA
Guilian University, Faculty of Agriculture, Rasht, Iran
KAZEMPOUR, Mostafa Niknejad and Seyed Ali ELAHINIA, 2007. Biological control of Fusarium fujikuroi, the causal agent of Bakanae disease by rice associated antagonistic bacteria. Bulg. J. Agric. Sci., 13: 393-408
In this research, effect of some isolates antagonistics bacteria were investigated against Fusarium fujikuroi the causal agent of bakanae disease and foot rot of rice, collected from infection farming in Rasht, Lahijan, Foman, Anzaly, Talesh and Astara in the Guilan Province under greenhouse conditions. Two hundred thirty eight bacterial isolates, separated from the rhizosphere and seeds of rice infected by the fungus which mentioned above and antagonistic ability of 13 isolates of these bacteria (8 gram negative and 5 gram positive) were demonstrated by using the dual culture method. According to the results of biochemical and morphological trials, 8 isolates: F1, F6, F12, F15, F16, F18, F21 and F25 were identified as Pseudomonas fluorescens. Five isolates, F14, F19, F21, F32 and F35 were introduced as Bacillus cereus. In greenhouse conditions antagonistic isolates were used by seed, plant and soil treatment. Statistical analysis of data indicated that there existed significant differences between seed, plant and soil treatments. The isolate F15 in seed, plant and soil treatment was most effective and disease incidence by 8.5, 8.5 and 12 % respectively. While the isolates F6 was least effective on F. fujikuroi. All of the isolates in seed treatments are more effective compared to other treatments. The results of used the mixed Rovral TS fungicide with mixed antagonistic isolates showed that there existed significant disease incidence by 6.5, 6.75 and 8 % respectively. In the field conditions foliar spray of isolate F15 mixed with Rovral TS (52.5% WP) were applied. The disease incidence in F15 isolate for seed coating, soil drenching and seed coating + foliar spray were 6.5, 6.75 and 5.5 % respectively, while the control plants showed 28% disease incidence. These results suggest that the P. fluorescens and B.cereus isolates studied have an excellent potential to be used as biocontrol agents of F. fujikuroi in rice at the field conditions.