Biological Control of Strawberry Bud Rot Caused by Rhizoctonia solani AG2-1 with Antagonistic Microorganism

길함미생물에 의한 시설재배 딸기 눈마름병의 생물학적 방제

Forth microbial isolates out of 167 isolates from the soil of controlled cultivation areas inhibited mycelial growth of Rhizoctonia solani AG2-1 causing the strawberry bud rot in vitro. Among the isolates, Kr013 and Kr020 showed suppressive effect to R. solani AG2-1 on seedlings of chinese cabbage treated by root immersion, charcoal carrier granule and drenching on 1.0% infested soil in pot. Furthemore, the corresponding effect was also revealed when the charcoal carrier granule of the isolates were treated on the seedling of strawberry that were planted on the planting hole in pot. To examine the effects of biological control in green house, it had been tested the infection rates by using two different treatments. First, the strawberry runner were planted on the nursery soil mixed with 20% charcoal carrier granule of Kr013 and Kr020 isolate respectively, and grown for 20 days before transplanting. Then the young plants form the mother plant were separated and transplanted on the 1.0% infested soil. Another method was that the charcoal carrier of Kr013 and Kr020 isolates applied to planting hole of 1.0% infested soil just before transplanting. Then the young plants were grown for 20 days on the sterilized nursery soil before transplanting. From the results, the effects of biological control was significantly higher on former treatment (e.g. the infection rates were 7.3 and 5.7%, respectively) than on the latter treatment (e.g. the corresponding value were 16.7 and 15.7%, respectively). The antagonistic isolates of Kr013 and Kr020 were respectively identified as Pseudomonas cepacia with the similarity of 55.0% and 60.0% by using the Biolog GN Microplate system.