不同生长阶段群体数量特征对产草量作用的分析

在相同的光，温，水，肥条件下，同时对营养生长期的高羊茅和生殖生长期的多年生黑麦草人工草地产草量和群体数量特征的定量关系进行研究。在营养生长期，参数的变异程度小于生殖生长期。营养生长期各因子对产草量直接作用的程度排序这：叶面积指数〉草丛高度〉分蘖密度，生殖生长期为；草丛高度〉叶面积指数〉分蘖密度。

Contributions of Sward Population Structure to Herbage Production in Two Growth Stages

Quantitative relationships between herbage production and sward population structure factors were studied for tall fescue in the vegetative growth stage and perennial ryegrass inthe reproductive growth stage, under same greenhouse conditions of light, temperature, irrigationand soil fertility. In vegetative stage, variability in these traits were smaller than in reproductivestage. Factor ranks in direct contributions of the factors to herbage production of swards were asfollows: leaf area index>sward height > tiller density in vegetative stage, and sward height > leafarea index> til1er density in reproductive stage. Patterns of direct and indirect contributions dif-ferent in two growth stages. All the difference above should be taken into consideration whensward production is evaluated, so that complete understandings into grassland performance mayreach.