杨树溃疡病及其防治技术的研究

Studies on the Techniques of Controlling Poplar Canker Disease

The poplar canker is a perilous disease which infected almost 300.000 mu of poplar plantation in Liaoning Province. Its typical symptom is the beister-like spots on the bark. If the spots surround the stem. The upper part will die. According to the observation of diseased tissue and the tests of inoculation it has been verified that the causeal organism is Dothior- ella gregaria Sacc. In Liaoning Provine this disease occured in the begin- ning of April and reacted to its peak from the and of April to the later part of May, and gererally stopped in the later part of June; otherwise, there was a second peak in the earlier part of September. From 1987to 1989,the total curing area of the disease had reached to 11000mu. Smearing of 11371,Tubiging, non-phenol free washing oil was confirmed to be eff- ective in controlling this disease, and so was spraying of Asomate and Bavistim Solution.