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通过系统观察，香荚兰根腐病周年发生，随种植时间延长而病情累积增高。新增病根发病率增高在高温季节，而在低温干旱季节降低。根腐病发病率＜５０％的调查样方有１９．７％的表现出蔓叶发黄；发病率＞６０％的，则有９０％以上的蔓叶发黄，可以把发病率＜４０％作为该病的控制指标。田间管理好，根系发达，生长良好的园地，病情较轻。离体幼根接种试验表明，根尖和根毛区是病原主要的入侵部位。有１５％的幼根不感病，大多数感病根，病斑扩展到一定程度即停止活动，仅有１２％的根病斑发展到全根死亡。病斑扩展期为２～７ｄ，扩展速度为０．２～８．４ｍｍ／ｄ。
Through systematic observation, vanilla root rot occurs annually, with the prolonged planting and disease accumulation increased. The incidence of newly-increased root causes increased in the hot season, but decreased in the cold and dry season. The incidence of root rot <50% of the surveyed quadrats showed 19.7% of the leaves were yellow; the incidence of> 60%, then more than 90% of the yellow leaves, can the incidence of <40% As a control indicator of the disease. Good field management, well-developed, well-growing garden, the less serious condition. In vitro root prion inoculation experiments showed that the root tip and root hair area is the main invasion of the pathogen. 15% of the young root does not feel sick, most of the diseased root, lesion extended to a certain extent that stop the activity, only 12% of the root spot disease developed to all root death. Lesions extended for 2 ~ 7d, the expansion rate of 0.2 ~ 8.4mm / d.