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考察叶面积动态有助于研究作物生育状况和羣体结构,为采取适当的增产措施提供依据。作物叶面积的测定方法颇多,其中以求积仪测定的结果最准确,但需相当的设备,且花费人工和时间较多,非广大农村所能采用;取样推算和称重法,也需一定的设备,准确性还不高;分级估计法,虽然简便,准确性差;至于方格纸测定法,准确性虽高,操作过程繁琐。一般在大田生产中多采用量测法测定未谷类作物叶面积,主要是因为这种方法无需仪器设备,操作简便,结果又较准确。对禾谷类作物叶面积进行简易量测,国内外所用方法不尽相同,测定结果亦有出入,在实际应用中,究竟那种方法较好,尚待探封。目前对禾谷类作物叶面积量测法争论的焦点在于测定叶片上什么部位的宽度及系数的合理程度问题。具体来说,是采用叶最宽,或叶中宽,还是叶基宽和系数大小的差别。兹就量测五种禾谷类作物叶面积的结果,讨论如下。
It is helpful to study the crop growth status and population structure to study the dynamic changes of leaf area, so as to provide the basis for appropriate stimulation measures. There are many methods to determine the leaf area of crops, of which the plot to determine the plot results the most accurate, but requires considerable equipment, and labor-intensive and time, non-majority of rural areas can be used; sampling and weighing method, also need Certain equipment, the accuracy is not high; grading estimation method, although simple, poor accuracy; as the grid paper determination, the accuracy is high, the operation is cumbersome. Generally in the field of production and more measurement method used to determine the leaf area of non-cereal crops, mainly because this method without instruments and equipment, easy to operate, the result is more accurate. Simple measurement of cereal leaf area of cereals, methods used at home and abroad are not the same, the results also vary, in practice, what kind of method is better, pending exploration. At present, the focus of controversy on measurement of the leaf area of cereal crops lies in the question of the reasonableness of determining the width and coefficient of any part of the leaves. Specifically, the leaf is the widest, or leaf wide, or leaf-based and coefficient of difference between the size. Here are the results of measuring the leaf area of five cereal crops.