1864年前后德国植物生理学家Julius sachs设计的半叶法测定植物的总光合强度,由于它简便易行,不需要精密的仪器,特别是能在田间自然条件下定量测定作物的总光合强度,加上易于增加测定样本数而提高其结果的代表性,所以一百多年以来,不少的试验中都采用它,并陆续有所改进。本世纪七十年代初期,我国上海植物生理研究所的同志们提出了“改良干重法测定光合强 The half-leaf method designed by the German plant physiologist Julius sachs around 1864 determines the total photosynthetic intensity of a plant. Because it is simple and easy, it does not require sophisticated instruments. In particular, it can quantify the total photosynthetic intensity of crops under natural conditions in the field. On the other hand, it is easy to increase the number of samples to be measured and increase the representativeness of the results. Therefore, it has been adopted in many experiments for more than one hundred years and has been gradually improved. The early seventies of this century, China’s Shanghai Institute of Plant Physiology comrades put forward "improved dry weight method to determine photosynthetic strength