Comparison of the growth and yield of paddy and upland rice grown under paddy and upland field conditions
Hasegawa, S.'ichi; Nakayama, K.
Proceedings Crop Science Society Japan 27(3): 354-356
Paddy rice variety Fujisaka No. 5 and upland varieties Norin No. 12 and No. 21 were grown on both lowland and upland fields. Factors such as number of ears and grains per ear, which are determined by heading time, are more important under upland field conditions. Such factors as percentage of heavy, ripe grains, which work after heading, dominate in the paddy fields. Of the carbohydrate in the ripe grain, more is produced and stored before heading in the upland while the greater part of it is produced after heading in the paddy fields. Upland varieties do well in their fields because they produce and store much carbohydrate before heading time. The paddy rice variety yielded about 22% less on upland soil in spite of its higher rate of photosynthesis after heading there. Irrigation increased carbohydrates formed both before and after heading but the paddy variety did poorly on the upland fields because it still lacked enough soil moisture.