Varietal Differences in Growth, Lodging and Related Characters of Rice Plants Broadcasted in Submerged Paddy Field at Different Densities(Agronomy)

Japanese Journal of Crop Science

Tadashi HIRASAWA¹  Yumiko SAN-OH¹  Taiichiro OOKAWA¹  Namie AIZAWA¹ 

关键词: Direct sowing in submerged paddy field;    ??;    Flexural rigidity;    ??;    Grain yield;    ????;    Lodging;    ?????????;    Moment of inertia of area;    ??;    Planting density;    ?????;    Rice;    ????;    Young's modulus;    ????;   

DOI  :  10.1626/jcs.70.515

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

References(27)Cited-By(6)Seeds of rice cultivars, Nipponbare, Takanari and Chugoku 153 were broadcasted in the submerged paddy field at different densities. The density of seedlings after establishment was in the range of about 60 to 240 plants m-2 Nipponbareand Chugoku 153, and about 40 to 130 plants m-2 Takanari. Serious lodging occurred in Nipponbare at the ripening stage due to bending at the base of the stem, and the degree of lodging tended to be larger in the stand with a higher density. The lodging was slight in Chugoku 153 and Takanari. A close correlation was observed between the degree of lodging and the reduction in grain yield. In the direct-sown plants without serious lodging, the grain yield was comparable to or even larger than the conventionally transplanted plants. The flexural rigidity of the stem at basal internode, which affects the lodging due to the stem bending, was larger in Chugoku 153 and Takanari. The larger flexural rigidity was caused by both of culm and leaf sheath in Chugoku 153 and mainly by culm in Takanari. In Nipponbare, the flexural rigidity of the stem was the smallest due to the smaller fiexural rigidity of the culm with smaller moment of inertia of area. The larger culm fiexural rigidity resulted from the larger Young's modulus in the stand with lower density and smaller degree of lodging in Nipponbare. These results indicate that a larger moment of inertia of area and Young's modulus are important characters for increasing the flexural rigidity of the culm.

【 授权许可】

Unknown