山东杨树大斑溃疡病研究

STUDY ON POPLAR CANKER DISEASE IN SHANDONG

Poplar canker disease caused by Dothichiza populea Sacc. et. Briard was first found inJiaonan and Changyi Counties, Shandong Province in May of 1984. Mortality of Populus euramericana (Dode) Guinier cv. 'Sacrau 79' in heavily diseasedstands and places appeared to be as high as 80~90%. The germination of conidia wasfavarred on PDA membrane or nutritious liquid drops, at pH 6~7, at warmtemperature of 2512 and in darkness. The conidia could survive about 4~5months but not through summer. The conidia infeeted poplar from April to July. Thepathogenic fungi were characterized by latent infection. The disease began to develop in theearly and middle of March and became serious in the early and middle of April and thenstopped developing in the middle and late of May. It did not develop in autumn. Theincubation periods for artificial inoculation were two or three months in December and onemonth in March and twenty-two days in April. The disease was closely related to the siteconditions, management techniques and poplar growth potentials, and also to the host spe-cies to some degree. Fungicide tests showed that asomate tezet and ambam were most effec-tive. It is suggested that integrated silvicultural practices and pest managements in control-ling the disease should be adopted to improve the tree hardness and disease resistance.