(36(4):435-444)Control of Fusarium Wilt and Root Rot of Garden Peas by Soil Amendments

豌豆萎凋及根腐病菌之厚膜抱子在酸性土壤中皆可發芽良好，其發芽率隨pH值上升而降低，但在pH4-7之間，並不影響病害發生程度，惟有pH7.4之處理才有顯著差異。在溫室裡，添加不同劑量之氰氮化鈣，SH混合物，及石灰於土中(pH4.2)，可提高容積土壤及根圈土壤之pH值，但隨時間之增加，根圈土壤pH值會被中和而趨近於6-7之間。氰氮化鈣可抑制萎凋及根腐病菌及其引起之病害，SH混合物則僅抑制萎凋病(菌)，而石灰處理則毫無抑制作用。在新社試驗田(萎凋病)，經上述土壤添加物處理後，各種添加物皆不太影響容積土壤之pH值。一九八五年期，各種添加物並不影響土壤中病原菌之族群密度，但是氰氮化鈣可抑制萎凋病的發生，而SH混合物(臺肥公司產品)及石灰處理則可延遲病勢的發展。一九八六年期，各種添加物亦不太影響土壤中病菌族群密度，但是氰氮化鈣及SH混合物(實驗室製造)則可抑制萎凋病，石灰處理則否。土壤pH值似乎非其抑制因于，其抑制機構則有待進一步研究。 The chlamydospores of Fusarium oxysporum f. sp. pisi and F. solani f. sp. Pisi could germinate well in acid soil. The germination rate was reduced by increasing the soil pH. However, both wilt and root rot diseases were reduced only at pH 7.4, not at the range of pH 4.0 to 7.0. In greenhouse, adding different dosages of calcium cyanamide, S-H mixture and lime to the soil (pH 4.2), the pH values of both bulk and rhizosphere soils were raised, but the rhizosphere soil pH was neutralized to 6.0 to 7.0 with time. Calcium cyanamide could inhibit the wilt and root rot pathogens and diseases; S-H mixture could only inhibit the wilt pathogen and disease, but lime had no effect. In Hsin-sir experimental plots, the bulk soil pH values and both wilt and root rot pathogens were not changed very much by using soil amendments. In the plots of 1985, wilt disease was inhibited by calcium cyanamide and reduced by S-H mixture (product of Taiwan Fertilizer Company) and lime. In the plots of 1986, however, both calcium cyanamide and S-H mixture (home-made) could reduce the wilt disease, but lime had no effect. Soil pH seems not to be the main factor. More researches on the mechanisms of disease suppression need to be done in the future