用苦楝、银杏、樟树与杨树抗病品种和感病品种的内含物进行杨树溃疡病测试，从孢子发芽、菌丝生长及植物抗病能力的测定结果证明：苦楝、银杏和樟树内含物对溃疡病的抑制作用比抗溃疡病的杨树品种作用强，特别是苦楝和银杏表现更为突出。 Poplar canker disease tests were carried out on the contents of the resistant varieties of Melia azedarach, Ginkgo biloba, camphor tree and poplar, and the content of disease-resistant varieties of poplar. The results of spore germination, mycelial growth and plant disease resistance showed that the contents of Melia azedarach, The inhibitory effect on canker disease is stronger than anti-ulcer disease poplar varieties, especially the performance of neem and ginkgo more prominent.