Antagonistic/Synergistic Effects Of Entomopathogenic Fungi Beauveria Bassiana And Bacteria Bacillus Thuringiensis Species Against Insect Pests Of Rice

The rice crop is one of the most vital cereal crop. It provides food for nearly half of the world's population. It is attacked by numbers of insect pests which cause serious damage to the crop. Generally synthetic pesticides are used to control insect pests but these pesticides have serious impacts on the environment and human health. Keeping in view, the present study was conducted to determine the efficacy of microbial pesticides against insect pests of rice. The entomopathogenic fungi and Bacillus species were used for experimentation. The rice plants were grown in pots and in the field. The experiments were done in pots with three experiments as well as in the field by using the entomopathogens alone and in combinations. At the emergence of plants different concentrations of entomopathogens were applied against rice pests. After the application the population reduction percentage data in pots was noted after 24, 48 and 72 hours and in field the population reduction percentage data was noted after 48 and 72 hours. The field data was collected after every three days of application for the evaluation of long term efficacy of entomopathogens until the second application. The highest population reduction of rice leaf folder and sugarcane pyrilla was caused by pure formulation. The fungal isolate alone produced 45.62 and 81.73% reduction of rice leaf folder population after 48 and 72 hours respectively after the application of pure formulation. Bacillus thuringiensis alone produced 45.69% and 81.98% reduction of rice leaf folder after 48 and 72 hours respectively after application of pure formulation while the combination of both fungal and bacterial pure formulation produced 75.23% and 89.93% reduction in population of rice leaf folder after 48 and 72 hours respectively. Pure formulation of fungus also caused the population reduction percentage of Sugarcane pyrilla and produced 42.93% and 64.40% reduction in population after 48 and 72 hours while the pure formulation of bacteria alone produced 66.26% and 76.95% reduction in population of Sugarcane pyrilla. The combinations of both formulations produced 72.96% and 82.59% population reduction percentage after 48 and 72 hours respectively. The highest population reduction percentage was produced by Bacillus thuringiensis alone in pots experiment is 47.19%, 81.54% and 90.29% after 24, 48 and 72 respectively, while Beauveria bassiana produced 45.64%, 62.39% and 79.44% population reduction percentage after 24,48 and 72 hours of application. The combination of both formulations provided 52.64%, 90.31% and 90.39% population reduction percentage after 24, 48 and 72 hours. So it is concluded that microbial pesticides can be used as potential biocontrol agent against insect pests of rice with no harmful effect on our ecosystem.