Biological Control Effects of Fusarium sp. Against Orobanche in Tobacco Field

In order to reduce the damage by orobanche in tobacco field,a novel Fusarium sp. separated and bred in lab was tested to study its biological control effects against orobanche in tobacco field. The results showed that the treatment involving tobacco field soil pH adjustment with sulfur prior to hole applying Fusarium sp.,and spraying Fusarium sp. three times at the early stage of orobanche parasitism possessed the best effects, in which the emergence time of orobanche was delayed by 3 days comparing with the control,the orobanche ratio of parasitized by Fusarium sp. was 31.20%,the field control effect to orobanche reached 62. 44%,meantime, the occurrence of other diseases was much lighter,the yield of tobacco leaf was 4895kg/ha,the percentage of high and middle grade leaves was up to 89.89%,i. e. 33.95% higher than that of the control.