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一、症状的观察和描述 症状是感病林木外观上表现的特征,它对病害的识别或鉴定有很大的价值。对任何一种植物病害进行调查研究时,首先要认识它的症状,否则就可能搞错。 每一种植物病害的症状都有自己的特点,因此可以作为识别病害的根据。但完全依靠症状来识别病害有时又是不够的,因为不同的病害可能具有相似的症状,在这种情况下,只有鉴定病原来加以区别。
First, the symptoms of observation and description Symptoms are the characteristics of the appearance of susceptible trees, its identification or identification of disease has great value. To investigate any kind of plant disease, we must first understand its symptoms, otherwise it may be mistaken. The symptoms of each plant disease have their own characteristics, so can be used as a basis for identifying the disease. But relying solely on symptoms to identify the disease is sometimes not enough, as different diseases may have similar symptoms, in which case only the pathogen is identified for differentiation.