【摘要】 从2017年4月中旬至12月上旬调查了南京城北地区银杏叶枯病的发生情况,结果表明:南京城北地区银杏叶枯病发病高峰期的叶片症状可分为边缘黄化型、斑点型、焦枯型、均匀黄化型4类,其中边缘黄化型发生比率较高;南京城北地区银杏叶枯病发生较为普遍,一般始发时期为5月中下旬,至7—9月是危害高峰期,病害迅速发展,10月中旬左右危害逐渐停止,病情指数达65. 28,11月后叶片逐渐枯黄脱落;不同的养护管理条件对该类病害的发展也有影响,至10月中旬,在有养护管理措施的新庄地区,该病害的发展较轻,病情指数为39. 3,而无养护管理的晓庄幕府校园内的银杏树的病害发展较重,病情指数达到85. 4;南京城北地区银杏雌雄株叶枯病发生情况的调查研究表明雄株发病较早,5月病情指数为14,而雌株为5. 4,但雄株病情发展缓慢,至10月中旬,雄株比雌株个体表现更为抗病,雄株和雌株病情指数分别为40和56. 4。更多还原

【Abstract】 The occurrence of the leaf blight of Ginkgo biloba in the north area of Nanjing was investigated from April to December in 2017. The results showed that( 1) The symptom of the leaf blight in this area could be roughly divided into four types,i.e.,marginal etiolated type,spotted type,scorched type,and uniform yellowing type. And the incidence of marginal etiolated type was higher than that of the others;( 2) As a common disease in this area,its originating period was in the mid-late of May,and the peak period was from July to September. In the middle of October,the development of the disease ceased. The disease index could attain 65. 28,and after November,the leaves became gradually withered,yellow and falling off;( 3) The maintenance management could repress the development of the disease. In the middle of October,the occurrence of the disease with good maintenance management around Xingzhuang was light,with 39. 3 of disease index,but that of the disease in Mufu school district was serious,with 85. 4 of disease index;( 4) Male plant had the early onset,with 14 of disease index in May while the occurrence in male plant developed slowly with 5. 4 of of disease index. Male plant had a more resistance than female plant in the middle of October.更多还原