The effects of pH, relative water content, and different kinds of nitrogen on the proliferation of the pathogen of cu-cumber Fusarium wilt in soil were investigated by laboratory experiments in this study. The results demonstrated that pH signifi-cantly affected the proliferation of the pathogen in soil. The proliferation rate of Fusarium oxysporum was much higher at pH 3. 0 and 5. 0. Only a little proliferation of the pathogen was observed at pH 7. 0 and 9. 0. The pathogen proliferated quickly when the relative water content of soil was between 10% ~30%. Both nitrate nitrogen and ammonium nitrogen had the promotive effect on the proliferation of the pathogen. The proliferation rate increased with the increasing of nitrogen concentration. Com-pared with nitrate nitrogen, use of ammonium nitrogen made the pathogen proliferate faster. This was mainly because ammoni-um nitrogen could be more easily utilized by most microorganisms. Totally, in this research the effects of different soil environ-mental factors on the proliferation of the pathogen of Fasurium wilt in cucumberwas illustrated. The result would do help to im-prove the effect of the biological control of Fasurium wilt in cucumber.%通过实验室模拟试验，研究了连作土壤中pH值、相对含水率及施用不同类型氮肥等环境因子对土壤中黄瓜枯萎病致病菌( Fusarium oxysporum f． sp． cucumerinum)增殖的影响。研究结果表明，土壤pH值对致病菌的影响最显著，致病菌增殖速率在初始pH值为3．0和5．0时显著高于pH值为7．0和9．0；土壤相对含水率在10%~30%之间时，有利于尖孢镰刀菌的生长繁殖；施用不同形态氮肥对致病菌在土壤中的增殖均有促进作用，且随施用量的增加而增加，其中铵态氮更易导致致病菌快速增长。研究结果阐明了黄瓜枯萎病致病菌在不同土壤环境因子影响下的增殖规律，将有助于指导黄瓜枯萎病防治，提高防效。
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