福岡県農業総合試験場研究報告22(2003) pp 38 - 42
水稲品種‘あきさやか’の高品質・良食味および安定多収のための施肥方法
川村富輝・石塚明子
（筑後分場）
水稲晩生品種‘あきさやか’の良食味・高品質・安定多収のための窒素施用法を明らかにした。
１．同一施肥方法では，‘あきさやか’は‘レイホウ’に比べて，籾数が確保しやすく，登熟歩合が安定して高く，収量性は5〜7%優れる。
２．‘あきさやか’の食味が‘コシヒカリ’並で，検査等級が優れ，さらに収量が安定した施肥方法は， 10a当たりの窒素量で基肥5kg，穂肥は第1回目が3kg，第2回目が2kg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日頃である。
３．‘あきさやか’の食味をさらに向上させるには，10a当たりの基肥窒素量を5kgから2kg減肥し3kgとする。なお，その場合収量が3%程度低下する。
４．‘あきさやか’は第2回穂肥を省略，または穂肥を早期施用すると登熟歩合と千粒重が低下し，収量が5%程度低下する。
[キ−ワ−ド：水稲，あきさやか，食味，品質，収量]
Fertilizer Application Method for High Quality･High Palatability and Stable Yield Using The New Rice Cultivar, ‘Akisayaka'. KAWAMURA Yoshiteru and Akiko ISHITUKA (Fukuoka Agricultural Research Center, Chikushino Fukuoka 818-8549, Japan)Bull. Fukuoka Agric. Res. Cent. 22:38 - 42 (2003)
This study was carried out to establish nitrogen application techniques for high quality, high palatability and of stable yield for the recently developed late-maturing rice cultivar ‘Akisayaka'.
(1)Compared to ‘Reihou', ‘Akisayaka' had a higher number of spikelets and percentage of ripened grains, with yield increased by 5 to 7% .
(2)The fertilizer application method for high palatability, high inspection grade and stable yield for ‘Akisayaka' was as follows:
･5.0kg of nitrogen per 10a for basal dressing;
･3.0kg of nitrogen per 10a for the first application of top dressing at the panicle formationstage; and
･2.0kg of nitrogen per 10a for the second application of top dressing at the panicle formation stage.
With this fertilizing method, the palatability level of ‘Akisayaka' was judged the some as that of ‘Koshihikari',
(3)The palatability improved with a basal dressing application with reduced nitrogen content i.e. 2.0kg of nitrogen per 10a rather than 5.0kg, however yield per unit decreased by 3%.
(4)The percentage of ripened grains, thousand-kernel-weight and yield per unit uniformly decreased if the top dressing at panicle formation stage was applied one week earlier than usual, or if the second application of the top dressing at panicle formation stage was not applied at all.
[Key words: Rice, ‘Akisayaka', Palatability, Quality, Yield]