ON THE EFFECTS OF SHADING AND PINCHIG IN SOYBEANS.(Preliminary report)

Abstract

1. The effect of shading for two weeks during the early stage of growth was examined. At the same time, the effect of pinching tried at the biginning of shading was observed. 2. Two varieties were used, the one was Akazaya-shirodaizu, formerly classified by the author as an autumn type, and the other Kosa-mame, generally recognized as a resistant variety to shading. 3. When the shading was finished, the following facts were observed; a) By shading, the stem was exceedingly elongated and the branching was more restrained. b) By pinching the shaded plants, these unfavorable effects of shading were lessened to some extent. 4. The difference in the ecological characteristics of the tested varieties was observed in the matured plants in the following way; a) In variety Akazaya-shirodaizu, the shading elongated the stem, restrained the branching of plants and decreased the yield of seeds. But by adding of pinching these unfavorable effects were checked and the yield of seeds was remarkably increased. b) In variety Kosa-mame, the effect of shading appeared in the slight decrease of seed yield and the added pinching scarcely gave any influence upon the yield of seeds. (The Contribution in The Institute of Crop Science, Faculty of Agriculture, The Kyoto University)