玉米苗期是生根发叶的营养生长时期,且地下部生长较快,地上部生长较慢。第三叶展开后,种子内的养分已基本耗尽,完全靠自身吸收养分生长。因此,这一时期管理的主攻目标是促进根系发育,培育壮苗,做到苗全、苗齐、苗壮,为穗粒期的生育打好基础,搭好丰产苗架。我们通过1993年到1995年三年的实践,在苗期管理上主要采取了如下措施。 Maize seedling is the vegetative growth period of rooting leaves, and the growth of underground part is faster and the growth of shoot part is slower. After the third leaf is unfolded, the nutrients in the seeds have basically run out and the nutrients are grown solely on their own. Therefore, the main objective of management during this period is to promote root development, nurturing strong seedlings, so as to achieve seedling quality, seedling strength and seedling vigor, and lay a good foundation for the fertility growth of ear grains. Through the three years of practice from 1993 to 1995, we mainly adopted the following measures in seedling management.