Physiological and Ecological Studies of Rice Plant in Well-drained and Ill-drained Field. : (4) Differences in quality and ripening of rice grains as affected by fertilizers.

Abstract

Differences in qualities of starch, activities of amylase and phosphorylase, content of inorganic nutrient were investgated with plants grown on field with and without calcium silicate. The results are as follows: 1. Starch contained in the culms differs to the starch of the grains in the following points that (a) the former exerts more bluish coloration by Iodine reaction contrary to the redish coloration of the latter and also (b) the former shows larger transmittancy. 2. Transmittancy of starches in culms and panicles show high percentages, especially in the late ripening period, with the process of plant growth and in well-drained field as compared with illdrained field. 3. Amylase activities in culm bases especially at ripening time were declined in ill-drained field. These facts may be the important causes of the poor ripenihg in this field. 4. Weight of 1, 000 grains being a useful index of ripening was increased with the appilication of calcium silicate both in well-drained and ill-drained field, but when ammonium sulfates were too heavily fertilized, the effect of calcium silicate was not observed. 5. It was recognized that weight of 1, 000 grains shows a positive correlation with the percenages of silicate and phosphate contents in straws and panicles, but a negative correlation with the percentages of total nirtogen content.