근권 미생물을 이용한 제주지역 마늘 잎마름병에 대한 친환경적 방제

Abstract

Garlic is the second major crop plants following potato in Jeju island. Garlic leaf blight is severe between in middle of March and end of June which cause a loss of yield of garlic production. The major protection strategy against garlic leaf blight is an using chemicals which cause some problems such as destruction of agricultural ecosystem, pesticide resistance or chemical residues, if usage of the chemicals are indiscreet. Therefore, it needs alternative strategies which may be environment friendly. In this study, pathogen of garlic leaf blight was isolated from farm in Jeju island which was identified as Stemphylium vesicarium (Wallr.) Simmom. In order to select useful rhizobacteria, 50 bacterial isolates from Jeju and Chuja island were tested antifungal activity against garlic leaf blight pathogen in vitro test. Among them, inhibition of fungal hyphal growth were found in isolates THJ 609-3, KRY 505-3, MRL 412, BRH 433-2 and TRH 423-3. In the further experiments, the bacterial isolates THJ 609-3, KRY 505-3 and TRH 423-3 showed disease suppress of garlic leaf blight after inoculation with mixture of the isolate and pathogen suspension compare to with only pathogen suspension. The bacterial isolate THJ 609-3, which was most effective among the other bacterial isolates either in antifungal activity or in disease suppression, had a control value similar to those of commercial fungicide metconazole. Based on these results, the bacterial isolate THJ 609-3 may be useful as a biological control agent for protection of garlic leaf blight.