唐山市古冶区栽有梨树333多公顷，多是1986年以后栽植的。随着树龄的增大、产量的提高，梨黑星病日趋严重，发病程度因品种而异，鸭梨感病最重。此病为害叶片和果实，病果率为20％－80％。多数梨园因此病危害而严重减产，全区每年约减产2000t。为了掌握梨黑星病的防治技术，从1 Guye District, Tangshan City, pear trees planted more than 333 hectares, mostly planted after 1986. With the increase of tree age, the increase of yield, pears scab becomes more and more serious, the incidence varies according to breed, pear most susceptible. The disease damage leaves and fruits, disease rate of 20% -80%. As a result, most pear orchards have been severely affected by the disease and the yield has been reduced by about 2000 tons annually. In order to master pears scab control technology, from 1