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叶面积指数通常是单位面积内的叶面积与单位土地面积的比值,它的大小及其动态变化是衡量群体结构是否合理的一个重要指标。测定叶面积指数一般多采用简便的鲜重法,其方法如下。取样在大田或试验地里,取有代表性的麦株10—20株。测量将样株的全部绿色叶片剪下称重。记下10株绿叶鲜重;然后迅速将全部绿叶按其大、小、老、嫩分类,并根据各类绿叶的数目按比例选取30片,切取中段3或5厘米(a);立即称其鲜重,即为标准叶重;称重后将30段绿叶逐个铺平,量出总宽度(b):a与b的乘积,即30段绿叶的面积(平方厘米),即为标准叶面积。计算叶面积指数每亩绿叶面积(平方米)/666.7(平方米)=绿叶面积X0.0015(1/666.7平方米)
Leaf area index is usually the ratio of leaf area to unit land area per unit area. Its size and its dynamic change are important indexes to measure whether the community structure is reasonable. Determination of leaf area index generally use simple fresh weight method, the method is as follows. Sampling In the field or experimental site, take 10-20 representative wheat strains. Measurements All green leaves of the sample were cut and weighed. Make a note of the fresh weight of 10 green leaves; then rapidly categorize all the green leaves as large, small, old and tender, and select 30 pieces in proportion according to the number of all kinds of green leaves and cut the middle part 3 or 5 cm (a) The fresh weight is the standard leaf weight. After weighing, the 30 green leaves are paved one by one to measure the total width (b): the product of a and b, that is the area of 30 green leaves (square centimeters), is the standard leaf area . Calculate the leaf area index per acre leaf area (square meters) / 666.7 (square meters) = green leaf area X0.0015 (1 / 666.7 square meters)