作物和杂草均属于高等植物,用除草剂进行处理时,为什么只杀杂草而不伤害作物呢?其道理如下:1.形态、结构选择性不同植物的形态、结构、生长状况不同,因而它接触吸收除草剂的程度也不一样。麦田使用二甲四氯,一些阔叶杂草的芽暴露在外面,加上叶子阔大,接触药剂的量也多,容易中毒死亡。而麦苗的叶片狭窄、粗糙,药液不易粘在叶片上,它的生长点又被叶鞘层层包裹着,受害较少。2.位差、时差选择性利用除草剂处理土壤的深浅和作物与杂草生长的不一致特点来杀草。 Crops and weeds belong to higher plants, with herbicides, why weed only kill crops without harming it? The rationale is as follows: 1. Morphology, structure and selectivity of different plants in different morphological, structural and growth conditions, and therefore It is also exposed to different levels of herbicide absorption. In the wheat field, MCP was used. Some broad-leaved weed buds were exposed to the outside, and the leaves were wide and large, and the amount of contact medicine was also large, which was easily poisoned and died. The wheat seedling leaves narrow, rough, the liquid is not easy to stick to the leaves, and its growth point has been wrapped in layers of leaves sheath, less damage. 2. Potential difference, jet lag selective use of herbicides to deal with the depth of the soil and crop growth and weed inconsistent characteristics to kill grass.