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In order to find out effect on the inorganic and organic compounds as a soil amendment to control Fusarium wilt of cucumber caused by Fusarium oxysporum f. sp. cucumerinum, this study was conducted during the last two years from 1993 to 1995. According to add 14 inorganic chemicals (1%, w/v) including Al₂(SO₄)₃, individually in vitro, these chemicals were confirmed their suppression, and especially Alum, CaO and Al₂(SO₄)₃, suppressed not only 20.9∼25.0 percent on mycelial growth of the fungus, but also inhibited 72.8∼97% on conidial germination. Ca(NO,), suppressed mycelial growth only, while KCl, K₂SO₄, H₄NO₃, and Urea suppressed conidial germination. The 7 chemicals were finally selected. Composted pine bark (CPB) suppressed definely more than 90% on conidial germination in the different extract concentration (2,5 and 10%), although mycelial growth on extract medium of CPB and milled alfalfa leaves (MAL) were not remarkable. The antagonist Trichoderma sp. (Tr-3) mixed with an amended soil (1 %, w/w) containing composted pine bark showed a good mycelial growth to compete the causal fungus. And the antagonist Pseudomonas sp. (7-1-3) was also confirmed its antagonistic ability with culture filterate. It is known that a CPB soil amendment mixed with the two antagonists (1%, w/w) controlled almost completely Fusarium wilt of cucumber in greenhouse pots and a field experiment. It is therefore expected that biocontrol on Fusarium wilt of cucumber by a soil amendment can be applied to farmmer´s fields.
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