Abstract
A mycoparasite, Paraconiothyrium minitans CM2 was selected for biological control of sclerotinia rot of lettuce caused by Sclerotinia sclerotiorum. The experiment was carried out in a lettuce greenhouse in Yangpyeong from March to April.. When lettuce sclerotinia rot showed in the early stage of occurrence, Conidial suspension of the mycoparasite was weekly treated once to three times onto soil surface around lettuce plants. Incidence of sclerotinia rot in the once-application plot of the mycoparasite ($1{\times}10^7$ spores/$m{\ell}$) and in the benomyl(WP)-treated plot was 11.0% and 2.7%, respectively, whereas that of control was 31.0%. Incidence of twice- and three-application plots of the isolate was 7.9% and 12.8%, respectively. For increasing the effect of the mycoparasite, the experiment for the timing of application of P. minitans CM2 was carried out in a lettuce greenhouse in Yangpyeong and Suwon. Control efficacy against lettuce sclerotinia rot in the soil-drenching plots of P. minitans CM2 ($5{\times}10^6$ spores/$m{\ell}$) in the planting was 75.3~84.7%, and control effect by treatment of the isolate at the pot drenching+the soil-drenching plots in the early stage of disease occurrence was 63.8~58.0%. As the results, P. minitans CM2 could be a prospective biofungicide for biological control of sclerotinia rot of lettuce.
S. sclerotiorum에 의한 상추 균핵병의 생물적 방제를 위하여 기생진균 P. minitans CM2을 선발하였다. 경기도 양평군의 상추 시설재배포장에서 실험이 3월부터 4월에 수행되었다 상추균핵병 발생초기에 기생진균의 포자현탁액의 농도별로 7일 간격 1회 부터 3회까지 상추의 지제부에 관주처리하였다. P. minitans CM2($1{\times}10^7/m{\ell}$)의 1회 처리구가 11.0%, 베노밀수화제가 2.7%, 무처리가 31.0% 각각 균핵병이 발생하였고, 2회 관주처리가 7.9%, 3회 관주처리가 12.8% 균핵병이 각각 발생하였다. P. minitans CM2 균주의 처리시기에 대한 시험을 양평과 수원에서 실시하였다. P. minitans CM2 균주의 포자현탁액($5{\times}10^6/m{\ell}$)을 상추 정식직후에 관주 처리가 75.3~84.7%, 정식전 육묘 200공 연결포트에 관주처리한 후 균핵병 발생초기에 관주처리는 58.0~63.8% 방제효과를 나타내었다. 이와 같은 결과에서 P. minitans CM2 균주는 상추균핵병에 생물적 방제를 위한 유망한 미생물농약개발이 가능하다고 생각된다.
