Evaluation of Allyl Isothiocyanate as a Soil Fumigant against Soil‐borne Diseases in Commercial Tomato (Lycopersicon esculentum Mill.) Production in China

BACKGROUND: Root-knot nematodes (Meloidogyne spp.), soil-borne diseases and weeds seriously reduce the commercial yield of tomatoes grown under protected cultivation in China. Allyl isothiocyanate (AITC), a natural product obtained from damaged Brassica tissues, was evaluated as a potential replacement for the fumigant methyl bromide (MB) for use in the greenhouse production of tomatoes in China. RESULTS: The dose-response assay indicates that AITC has high biological activity against major bacterial and fungal pathogens (EC50 of 0.225-4.199 mg L-1 ). The bioassay results indicate that AITC has good efficacy against root-knot nematodes (LC50 of 18.046 mg kg-1 ), and moderate efficacy against fungal pathogens (LC50 of 27.999-29.497 mg kg-1 ) and weeds (LC50 of 17.300-47.660 mg kg-1 ). The potting test indicates that AITC significantly improved plant vigor. Field trials indicate that AITC showed good efficacy against Meloidogyne spp. and Fusarium spp. (both ∼ 80%) as well as Phytophthora spp. and Pythium spp. (both ∼ 70%), and improved plant vigor and marketable yield. CONCLUSION: AITC used as a soil fumigant (30-50 g m-2 ) effectively controlled major bacterial and fungal pathogens, root-knot nematode, weeds and increased plant vigor, yield and farmers' income in tomato cultivated under protected agriculture in China. © 2018 Society of Chemical Industry.