无芒雀麦地上部分干物质生产速度与繁殖生长的关系浅析

Superficial Analysis on the Relationship Between Rate of Dry Matter Production and Reproduction Grouwth of Smooth Bromegrass

根据地上部分干物质（ＤＭ）生产速度，将无芒雀麦的生长分为三个大的阶段：营养生长阶段、繁殖生长阶段和种子成熟发育阶段。在繁殖生长阶段（约５５ｄ），由于增加了两个在蕴藏状态下的更强的活动中心——茎和花序的生长，ＤＭ积累速度很快，日平均增加２９．４ｇ／ｍ２；地上部分总ＤＭ重量与茎和花序的重量保持同步增长，而叶子的重量稳定在４８８ｇ／ｍ２（±３２．２）。在茎和花序生长期间，任何过早的放牧或刈割利用都会因将茎的顶端除掉而导致ＤＭ产量大幅度下降。

The growth of smooth bromegrass (Bromus inermis) may be divided into three stages:vegetation,reproduction and seed ripe development,according to the rates of aboveground dry matter (DM) production.In the reproduction growth stage,DM production increases rapidly with a mean daily gain of 29.4g/m 2 because of the growth of two potentially active centres namely the stem and the inflorescence.Total weight of aboveground keeps synchronously increase with the weight of stem and inflorescence while leaf weight remains 488g/m 2.During the period of stem and inflorescence growth,grazing and any premature harvest will lead to a lower yield due to the removing of the stem apices.