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综合防治是植物保护的方向,但仍有些问题须待解决,其中之一是明确病、虫、杂草的危害性,进而制定合理的经济阀限。大约在60年代后期有些国家开始注意研究并制定害虫防治的经济阀限,到70年代初已获得一些成果。一、制定经济阀限的意义:自从杀虫剂大量使用以来造成了一系列消极的后果,诸如生物群落平衡遭到破坏、次要害虫作用增强、主要害虫产生抗药性以致再度猖獗、环
Integrated control is the direction of plant protection. However, some problems remain to be solved. One of them is to clarify the dangers of diseases, insects and weeds so as to formulate reasonable economic thresholds. Some countries began to pay attention to studying and formulating the economic threshold of pest control around the late 1960s and achieved some results by the early 1970s. First, the significance of establishing an economic threshold: Since the extensive use of pesticides, a series of negative consequences have been caused, such as the destruction of the balance of biomes, the enhancement of the secondary pests, the rejuvenation of major pests,