气候和土壤环境对作物生长发育的影响,可以通过苗情变化反映出来,所以看苗采取管理措施,有着重要的意义。在苗情调查中,观察叶的生长发育是确定苗情的一项重要内容。叶片诊断的生理指标叶龄主茎上出现的叶片数叫叶龄。按植株展开叶片的顺序数称第几叶龄。对同一地区固定的品种,叶片数是相对稳定的。因此,生长发育进程可用叶龄表示,它比用物候期作为标志更为确切可靠。叶龄与营养器官的生长和生殖器官的分化保持着一定的关系,它为农业生 The impact of climate and soil environment on the crop growth and development can be reflected by the change of seedling conditions. Therefore, it is of great significance to take measures to control the emergence of seedlings. In the Miao investigation, observation of leaf growth and development is to determine the Miao situation is an important part. Physiological indicators of leaf diagnosis Leaf age appears on the main stem of the leaves called the leaf age. According to the number of leaves in the order of plant development, said the number of leaf age. For the same species in the same area, the number of leaves is relatively stable. Therefore, the growth and development process available leaf age that it is more accurate and reliable than using phenology as a marker. Leaf age and the growth of vegetative organs and reproductive organs to maintain a certain relationship, it is for agricultural students