Growth Diagnosis of Rice Plants by Means of Leaf Color

Leaf color of rice plants has been regarded as important since old days, because it reflects best the nutritional status of the plants. Recently, as the preference for good quality rice caused increased cropping of varieties which have good quality but are Jess resistant to lodging, the leaf color comes to attract more attention from the viewpoint of preventing lodging. Therefore, if leaf color can be measured objectively and easily, and ap· propriate crop management is made based on the result of leaf color measurement, it will contribute a great deal to achieve stable and high yielding culture of rice. With such background, research on methods of measuring· leaf color has progressed, and it was made possible to measure leaf color easily in the field. There are two types of methods: use of machines or use of simple tools. The latter is more practical. Recently, a new tool named "Standard rice leaf color scale" (Fuji Film Co.) was developed. A series of studies on growth diagnosis by leaf color recently conducted are presented in this paper.