宁强县自1971年以来,先后飞机播种造林50万亩。现有一部分飞播较早的幼林已开始郁闭,平均树高5～6米,胸径6～12厘米,林分郁闭度0.7～0.9。从1982年以来,松落针病大量发生。为了巩固飞播造林成果,我们进行了一些调查和病源菌的流行规律观察,现将情况报告如下。一、松落针病危害的症状病害在针叶上,初期产生不规则的黄褐色斑点或段斑,逐渐变为黑褐色的横线。病斑呈长椭圆型,纵向分布于叶上,稍隆起即有性子囊孢子盘。如湿度大时,病斑中间开裂一条缝,放射子囊孢子,借风传播,扩 Since 1971, Ningqiang County has successively planted and sowed 500,000 mu of aircraft. Some of the existing young airplanes that started to fly earlier have begun to close. The average tree height is 5 to 6 meters, the diameter at breast height is 6 to 12 cm, and the stand canopy density is 0.7 to 0.9. Since 1982, a large number of loose needles have occurred. In order to consolidate the results of aerial seeding afforestation, we conducted some surveys and observation of the prevalence of pathogenic bacteria. The current situation is reported as follows. First, the loose needle disease endanger the symptoms of disease in the conifer, the initial irregular yellowish brown spots or spot, and gradually become dark brown horizontal line. Lesions were oval-shaped, longitudinally distributed in the leaves, slightly elevated that the ascospore disk. Such as humidity, the lesion cracks in the middle of a crack, radiation ascospores, spread by the wind, expansion