기온과 일장조건에 따른 벼 품종별 발육속도 및 출수기 (出穗期) 추정 = Originals : Estimation of Development Rate and Heading Time of Various Rice Varieties as affected Air Temperature and Day Length

다국어 초록 (Multilingual Abstract)

This study was conducted to get some basic information about rice plant development rate and heading ecology in various climatic conditions, growing nine varieties at three locations, Jinbu as the mountainous cool area, Suweon and Iri as the plain area for two years from 1987 to 1988. Average daily air temperature and day length from transplanting to heading date were analyzed in relation to the heading. Heading date and development rate of each variety were estimated by the Symplex method and the fitness of the model was evaluated. The results obtained as follows: Average daily air temperatures among varieties during the period from transplanting to heading ranged from 18 to 19℃ in Jinbu, from 22.5 to 23.5℃ in Suweon, and from 23.5 to 24.5℃ in Iri, the late-maturing varieties requiring the higher temperatures. The average heading days were about 20 days longer in Jinbu and 3~5 days shorter in Iri than those in Suweon in all varieties. Little differences in accumulated temperature from transplanting to heading were observed in regions and years, and also among varieties. Developmental stages could be expressed as the accumulation of daily development rate and the predicted heading dates by the Symplex method were similar to the observed ones. The development rate of each variety varies with air temperatures. The early maturing Japonica types including the Unbong variety were fast in development rate at lower temperatures, but the late-maturing varieties of the Japonica type were late. A model to predict the heading dates of rice varieties by the Symplex method using air temperatures and day lengths was feasible.