福岡県農業総合試験場研究報告23 (2004) pp 15 - 20
水稲品種‘つやおとめ’の高品質良食味および
安定多収のための窒素施用法
川村富輝＊・石塚明子
水稲中生の晩品種‘つやおとめ’の高品質良食味および安定多収のための窒素施用法を明らかにした。
１．‘つやおとめ’の食味，検査等級が優れ，さらに安定した収量を得るための窒素施用法は，10a当たりの窒素量で基肥が5㎏，穂肥は第1回目が3㎏，第2回目が2㎏とし，施用時期は第1回目が出穂前18日頃，第2回目は出穂前11日頃であった。食味は‘コシヒカリ’よりやや優れた。
２．中生の晩品種の基準基肥窒素量である7㎏では，籾数は多いものの，登熟歩合が低く，千粒重が軽いため，収量の増加はみられず，検査等級と食味が劣った。
３．第2回穂肥の省略，または穂肥の早期施用は，登熟歩合と千粒重を低下させ，検査等級が劣った。穂肥を減肥すると，籾数の減少により収量が4%低下した。また，これらの3種の穂肥施用法では，いずれも食味の向上効果は認められなかった。
［キーワード：水稲，‘つやおとめ’，食味，品質，収量］
Nitrogen Application Method for High Quality High Palatability and Stable Yield of The New Rice Cultivar 'TSUYAOTOME'. KAWAMURA Yoshiteru and Akiko ISHITSUKA (Fukuoka Agricultural Research Center, Chikushino, Fukuoka 818-8549, Japan) Bull. Fukuoka Agric. Res. Cent., 23: 15 - 20 (2004)
This study was carried out to establish nitrogen application techniques for high quality, high palatability and stable yield of the recently developed medium late-maturing rice cultivar 'TSUYAOTOME'.
(1)The nitrogen application method for high palatability, high inspection grade and stable yield of 'TSUYAOTOME' was as follows:
･5.0 kg of nitrogen per 10a for basal dressing;
･3.0 kg of nitrogen per 10a for the first application of top dressing at the panicle formation stage; and
･2.0 kg of nitrogen per 10a for the second application of top dressing at the panicle formation stage.
With this application method, the palatability level of 'TSUYAOTOME' was judged higher than that of 'KOSHIHIKARI'.
(2)The palatability and inspection grade deteriorated when more than 2.0 kg of nitrogen was added to the 5.0 kg of nitrogen per 10a for basal dressing application, while yield per unit didn't increase.
(3)The percentage of ripened grains, thousand-kernel-weight and inspection grade uniformly decreased when the top dressing at the panicle formation stage was applied one week earlier than usual, or when the second application of top dressing at the panicle formation stage was not applied at all. The yield per unit decreased because of a fewer number of spikelets when the nitrogen content in the application of the top dressing at panicle formation stage was reduced.
With these three nitrogen application methods of top dressing at the panicle formation stage, these palatability levels uniformly did not improve.
[Key words: Rice, 'TSUYAOTOME', Palatability, Quality, Yield]
＊連絡責任者（筑後分場）