对植物的病害进行诊断,首先应该知道植物病害是怎样引起的。按发病原因可将病害分为两大类:一、非传染性病害:植物在不适宜的土壤上,或是遇到不适合的气候、水分、肥料过多过少等所引起的病害。如甜菜地里如果土壤中缺乏微量元素“硼”,就要引起甜菜根变黑腐烂,叫做缺硼病。这一 The diagnosis of plant diseases, first of all should know how plant diseases caused. Diseases can be divided into two categories according to the cause of the disease: First, non-infectious diseases: plants in unsuitable soil, or encounter ill-suited diseases, water, excessive fertilizer and other diseases caused. Such as sugar beet in the soil if the lack of trace elements “boron”, we must cause the beet root black rot, called boron deficiency disease. This one