Floral Impotency Due to Cool Weather in Paddy Rice Plants in the Early-Season Culture Area : I. Relationship between light-intercepting characteristics and sterility

Japanese Journal of Crop Science

Tomio WATANABE¹  Yoshio TAKEICHI¹ 

关键词: Amount of fertilizer nitrogen;    過繁茂;    Cool-summer damage;    畦間気温;    Early-season culture;    受光態勢;    Light-intercepting characteristics;    障害型冷害;    Overluxuriant growth;    早期栽培;    Sunshine hours;    日照時間;    Temperature at the inside of leaf sheath;    基肥窒素施用量;    Temperature in the space of rows;    葉鞘内温度;   

DOI  :  10.1626/jcs.60.225

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

The present study was conducted to make clear the cause of promotion the sterility due to cool temperature at the booting stage by too much nitrogen application with investigating the relationship among the amount of nitrogen applied as basal dressing, treatment of cutting leaves and location of hills in the field and sterility under the different sunshine condition in 1982 and 1983 when cool-summer damage were occurred in paddy rice plants. The results are as follows. (1) For these two years, the sterility index has increased linearly with the amount of nitrogen and the increasing rate has been higher under the longer sunshine condition. The perfect unhulled rice yield index has decreased linearly under the longer sunshine condition. On the other hand, it indicated the curve of secondary degree with maximum value of about 11 kg/ 1O a of nitrogen under the shorter sunshine condition. (2) The increase of nitrogen application enlarged leaf area and the shading percentage in the space between rows. It prevented the rising of temperature in the space between rows, at the inside of the leaf sheath, of water and of earth on clear day. (3) Improvement of light-intercepting characteristics at the most sensitive stage to cool temperature by the treatment of cutting leaves decreased the sterility. It was caused by the rise in temperature at the inside of the leaf sheath. (4) The sterility of the hills at the edge of field, which received more sunshine, was lower than that at the inside of field. Within the same hill at the nearest furrow to levee in the west side of the field, the sterility of the panicles at the side of levee was lower than that at the side opposite to levee. (5) It can be concluded from these results that one of the causes of promotion the sterility due to cool weather at the booting stage by too much nitrogen application as basal dressing was the obstruction of temperature raising at various points surrounding rice plants with the deterioration of light-intercepting characteristics accompanying overluxuriant growth.

【 授权许可】

Unknown