稻叶是互生的,主茎上叶片数通常为10—19片。从叶尖露出下位叶的叶鞘到叶枕抽出所需天数,称做出叶周期。水稻一生各叶片的出叶周期可分为三组:离乳前抽出的3片叶(即第1、2、3片完全叶),出叶周期最短,一般平均为3天左右;分蘖期抽出的叶,出叶周期约为5—6天;拔节前后抽出的叶周期最长,约为7—9天。因此,可根据出叶的快慢来判断水稻的生长阶段。环境条件对出叶周期有很大影响。但温度的影响最明显,一般在32℃以下,温度愈高,出叶愈快,譬如矮南早1号,日平均 Rice leaves are alternate, the main stem leaves usually 10-19 tablets. From the leaves exposed lower leaves of the leaf sheath to leaf pillow out of the required number of days, called the leaf cycle. The leaves of rice leaves throughout the life cycle can be divided into three groups: three leaves before leaving the milk (that is, the first two or three leaves completely), leaf cycle the shortest, usually an average of about 3 days; during tillering out Of the leaves, leaves the cycle of about 5-6 days; pull out the leaves before and after the longest cycle, about 7-9 days. Therefore, according to the speed of leaves to determine the growth stage of rice. Environmental conditions have a significant impact on leaf outflow cycles. However, the most obvious impact on temperature, generally below 32 ℃, the higher the temperature, the faster the leaves, such as short Southern early on the 1st, the average daily