立毛状態での成熟期以降における品質変化 水稲の収穫作業期間延長に関する研究

Abstract

Possibility of elongation of harvesting period in paddy rice cultivar Nipponbare, Himenomai and Matsuyamamii, which are recommended varieties in Ehime prefecture, was investigated with changes in qualities on standing condition after maturation stage.1) The number of cracked rice kernel of Nipponbare, Matsuyamamii and Himenomai which were left in field, increased after fourteen days, one day and six months from the maturation stages, respectively.2) The number of colored grain of Nipponbare and Himenomai was less than that in Matsuyamamii.3) Although the inspection grade of Himenomai harvested after three months from the maturation was the first class, those of Nipponbare and Matsuyamaii harvested after three months from the stage were out of the standard because of a lot of cracked rice kernel.4) Himenomai harvested after two months from the maturation stage had the same eating quality as that harvested at the maturation stage. However, the eating quality that harvested after five months from the maturation stage was inferior to that the control one.5) The rice kernels were cracked by hygroscopicity, when moisture contents of unhulled rice were under 14%, 18% and 20% in Himenomai, Nipponbare and Matsuyamamii, respectively.6) These results lead to the conclusion that it is possible to elongate the harvesting period in paddy rice cultivar Himenomai.