农田杂草的危害众所周知。杂草与农作物共生,竞争力很强,据报道一株看麦娘平均能结籽4690粒,多的达39200粒;单株牛繁缕平均结籽1000～5000粒。杂草种籽具有多年生存(休眠)的特性,一旦散布在土壤里,就给杂草的防除带来了很大的困难。大部分杂草种籽不会自身移动,必须借助外力(风、水、动物等)才能传播,而人为的引种、调种(杂草种籽混入作物内)是杂草种籽扩散的重要途径。为了摸清上海郊区麦种内混杂杂草种籽的情况,防止其扩散,减轻田间杂草的发生基数,1983年冬, The hazards of farmland weeds are well known. Weed and crop symbiosis, highly competitive, it was reported that an average of 4690 plants can see Anemone, up to 39,200 more; single calluses an average of 1000 to 5000 seeds. Weed seeds have many years of survival (dormancy) characteristics, once dispersed in the soil, give weed control has brought great difficulties. Most weed seeds do not move by themselves and must be transmitted by means of external forces (wind, water, animals, etc.). Artificial introduction and breeding (weed seeds into the crop) are important ways for weed seed dispersal . In order to find out the situation of mixed weed seeds in the wheat seeds in the suburbs of Shanghai, to prevent their spread and reduce the occurrence of weeds in the field, in the winter of 1983,