Comparative Studies on Dry Matter Prodiction, Plant Type and Productivity in Soybean, Azuki Bean and Kidney Bean : V. Dry matter production of kidney bean at various population densities

[摘要] Two kidney bean cultivars, Taishokintoki (dwarf) and Tokachishirokintoki (determinate, bush) were grown in the equidistant square pattern at five population densities, and dry matter accumulation in plant conlmunities were analyzed. The main results obtained were summarized as follows: 1. Total dry weight was highest at the highest density (44.4 plants/m2), although the difference between 25.0 and 44.4 plants/m2 was very little. The maxirnum dry matter production was 641 g/m2 and 734 g/m2 for Taishokintoki and Tokachishirokintoki, respectively. 2. With increase in population density, dry weight of branches decreased more remarkably than that of main stem, but the ratio of the branch to the main stem was about 1 to 1 at the highest density. 3. CGR and LAI shifted higher with higher densities. NAR which was lower in higher densities, declined with progress of season, but rose temporarily at the middle of July. 4. Relative light intensity at the bottom of the canopy (logarithmic scale) decreased linearly with increasing LAI. The regression value (Ks) was low for Tokachishirokintoki, and the LAI requared for 95% light interception was 2.9 and 4.2 for Taishokintoki and Tokachishirokintoki, respectively. 5. The decrease in NAR with increase in LAI initiated from LAI 0.5. The decreasing rate was high for Taishokintoki with high Ks valuc. 6. LAIopt. and CGRnlax. were higher at stage III (the middle July) with larger solar radiation, compared with stage II and IV. At each stage the value of LAiopt. was high for Tokachishirokintoki, but the varietal difference of CGRmax. was very little. 7. The efficiency of dry matter accumulation per unit photosynthetically-activc radiation (PAR) intercepted (EPAR, dry weight rng/kcal) incrcased gradually up to the middle July and then decreased for Taishokintoki. However, those of Tokachishirokintoki were relatively constant up to the early August. The mean EPAR during the middle growing season (stage II-IV) did not differ between varicties and stages.

[学科分类] 农业科学（综合）