ENVIRONMENT-FRIENDLY CONTROL OF MAJOR DISEASES AT STRAWBERRY CULTIVATION REGIONS IN KOREA

In the environment-friendly farming system, Fusarium wilt and crown brown rot occurred during the planting period and powdery mildew and gray mold during the harvesting. They have been causing serious damages at strawberry cultivation regions in Korea. Fusarium wilt caused by the soil-borne pathogen Fusarium oxysporum f. sp. fragariae Winks & Williams, was harmful at early growth stage of strawberry. Control of Fusarium wilt causing soil-borne disease was tried by soil drenching after addition of rice and wheat bran (1-2 t/10 a). The density of Fusarium wilt decreased and disease occurrence also decreased after strawberry plantation. Antagonistic microorganisms were tested with respect to the control of gray mold and powdery mildew on strawberry. Bacillus velezensis isolate successfully inhibited mycelium growth of gray mold. Liquid formulation of B. velezensis antagonist was treated three times (1/week) for three weeks on gray mold in the field, resulting in higher control efficacy (50.2%) than registered bio-pesticide. When B. velezensis antagonist was sprayed three times with 5-day intervals on powdery mildew in the field, the disease was successfully controlled with control efficacy of 88.7%.