Induced resistance of acibenzolar-S-methyl (CGA 245704) to cucumber and Japanese pear diseases

Antifungal activity of the novel compound acibenzolar-S-methyl (CGA245704: benzo[1,2,3]thiadiazole-7-carbothioic acid S-methyl ester) was examined in vitro. No remarkable activity was observed on mycelial growth and conidial germination of almost all fungi tested. Only melon isolates of Didymella br yoniae were sensitive to this compound. On potted plants, acibenzolar-S-met hyl showed control efficacy on anthracnose and scab of cucumber and rust of Japanese pear but not on Fusarium wilt of cucumber. In field trials, the o ccurrence of both rust and scab on Japanese pear was suppressed with this c ompound. Based on these experiments, it was suggested that acibenzolar-S-me thyl induced resistance to some but not all diseases on cucumber and Japane se pear. Induction of disease resistance in cucumber was rapidly triggered after treatment with acibenzolar-S-methyl.