Effects of Shading Treatment upon the Plant Compositions and Respiratory Intensity of Wheat and Barley : Studies on the Growing Process of Wheat and Barley in the Warmer District of Japan, Part V.

Abstract

The authors carried out experiments upon the effects of shading on some physiological characters of wheat and barley plants at various states of their growth (Table I), and obtained the following informations. Dry matter per cent and contents of C compounds (total carbohydrate, total sugar and reducing sugar) of the plant shoot decreased by shading in different extents according to the stage of growth. The most conspicious effect was found at the critical stages from spike primordia differentiation to spikelet development. On the other hand, contents of N compounds increased conversely at the critical stages above mentioned. Respiratory intensity measured by the amount of O₂ intaked was also reduced by shading, and the periodical variation in its effect was seen upon the root part.