一、问题的提出 自古以来,在自然生态中,植物和植物的寄生物,两者在一定环境条件下发生关系,引起植物害。在原始农业情况下,寄主植物与寄生物达到“平衡状态”。当人类从事农业,参加到农业生态系中以后,就影响或导致植物病害发生,打破了“自然平衡”。 人类在农业生产活动中,为达到自己的目的,就逐渐学会同植物病害斗争,几千年间就有轮栽防病、晒种防病的经验,这些 First, the question raised Since ancient times, in the natural ecology, plants and plant parasites, both under certain environmental conditions, causing plant damage. In the case of primary agriculture, host plants and parasites reach “equilibrium”. When mankind engages in agriculture and participates in agroecosystems, it affects or causes the occurrence of plant diseases and breaks the “natural balance.” In the course of agricultural production, human beings have gradually learned to struggle against plant diseases for their own purposes. They have been using rotten plants for disease prevention and disease prevention for thousands of years and these have