Abstract
Estimation of the developmental stages of paddy rice by temperature (DVS method) was conducted during different cropping seasons and areas for the rice variety Koshihikari. The DVS method was applied to cases of transplantion from April 20 to June 1. During this period, the standard deviation of estimated error was 1.21, 1.48, and 1.45 days for the young panicle formation stage, heading stage, and maturing stage, respectively. However, the DVS method could not be used for transplanting on June 15, and the estimated developmental stages were somewhat behind actual growth rates. The developmental stage that appears to possibly be affected by the length of the day, and accelerated development was noted for short days. This method could be used in Nyuzen town, Tateyama town and Tonami city, all in Toyama prefecture, using temperature data from AMeDAS. Standard deviation of error was 2.76, 2.33, and 2.55 days for the young panicle formation stage, heading stage and maturing stage, respectively.
