叶片是植物光合作用的器官。果树科学研究中常把合理的叶面积系数作为丰产稳产的重要标志。叶面积系数大,说明叶片多;反之则少。一般果树叶面积系数达4—6时(耐荫树种可以稍大),较易丰产稳产。叶面积系数过大,树冠内部光照差,光合效能降低,不但不能增产,反而会降低产量和品质;叶面积系数低于3时,一般就是低产的指标。通常,果树叶面积系数的测量方法如下: (一)单叶面积测量 (1)求积仪法采下叶样后,立即随机取叶20片在纸上分别描下轮廓,再分别用求积仪测量面积,求出单叶面积平均值。此法较方便准确。 (2)方格法用叶面积方格测量板(在透明板上画上许多1平方厘米的方格制成,图1),统计单叶所占的方格数(叶缘凡占半格以上者按一格计,不足半格者不计)。可直接观测出 Leaves are photosynthetic organs of plants. Fruit tree scientific research often reasonable leaf area coefficient as an important symbol of high and stable yield. Leaf area coefficient, indicating more leaves; otherwise less. General fruit leaf area factor of 4-6 (shade-tolerant species can be slightly larger), easier to yield stable yield. Leaf area coefficient is too large, poor internal light crown, photosynthetic efficiency decreased, not only can not increase production, but will reduce the yield and quality; leaf area coefficient of less than 3, the general indicator of low yield. Normally, the measurement method of leaf area coefficient of fruit tree is as follows: (1) Measurement of single leaf area (1) After plotting the leaflet sample with the method of plotting, immediately take 20 leaves on the paper and sketch the outline separately, Measuring area, calculate the average single leaf area. This method is more convenient and accurate. (2) Square grid method with the leaf area measurement grid (painted on the transparent plate 1 square centimeter square made, Figure 1), the statistics of the number of single leaf grid More than one by a meter, less than half of those who do not count). Can be directly observed