西南暖地における早期栽培用·極早生水稲品種とさぴかの出穂特性

日本作物学会紀事

坂田 雅正¹  山本 由徳²  宮崎 彰²  平川 真由美² 

[1] 高知県農業技術センター;高知大学

关键词: Temperature;    温度;    Extremely early rice;    極早生水稲;    Heading characteristics;    出穂特性;    Cumulative temperature;    積算温度;    Early season culture;    早期栽培;    Earliness of variety;    早晩性;    Nitrogen application rate;    窒素施肥量;    Tosapika;    品種とさぴか;   

DOI  :  10.1626/jcs.72.163

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

In 1998, the occurrence of premature heading was observed in the earlyseason culture field of cultivar ‘Tosapika’ in Kochi Prefecture. The effect of growing temperature after sowing on the heading of the extremely early rice cultivar ‘Tosapika’, bred in Kochi Prefecture was studied comparatively with 49 cultivars and lines bred in various regions from Hokkaido to Kyushu.Pregerminated seeds were sown at a rate of one seed per pot in a stock-raising (kabumaki) pot which had a small hole at the bottom (2.5 cm depth) filled with nursery bed soil on March 10, 2000, which is the prevailing seedling time for the earlyseason culture in Kochi Prefecture. After seedlings emerged, kabumaki, pots were placed on containers, containing paddy soil with nitrogen at the rate of 1.5 g m-2 or 3.0 g m-2 and placed in the phytotron under natural light conditions with about 12 hours of day and night. Day (D) and night (N) temperatures were set at D/N of 30°C/20°C, 25°C/25°C or 25°C/15°C. Total accumulative temperature for the culture period was 1300°C days after sowing.The percentage of headed cultivars by at the end of the culture period was highest in the plot exposed to 25°C/25°C with 1.5 g m-2 nitrogen. Heading of the cultivars bred in Hokkaido were accelerated in the plot under 25°C/25°C and with 1.5 g m-2N. ‘Tosapika’ headed when the accumulated daily temperature was beyond 1000°C days. The heading was scarcely influenced by temperature and nitrogen level. Moreover, the accumulated temperature after sowing to flag leaf expansion was also lowest in ‘Tosapika’ among the headed cultivars, because of a fewer number of final leaves on the main stem in this cultivar. These two types accumulated temperature in ‘Tosapika’ were insensitive to temperature and nitrogen level, so it was suggested that the heading day of the main stem in this cultivar could be estimated by the accumulated daily temperature after sowing.

【 授权许可】

Unknown