[Prediction of the day on which sugi (Cryptomeria japonica D. Don) pollen scattering will begin--from view point of plant physiology].
We investigated the cumulative thermal constant and threshold temperature for the development of sugi (Cryptomeria japonica D. Don) male flowers to predict the day on which pollen scattering would begin. The threshold temperature for the development of sugi male flowers was 0.17 degrees C and the cumulative thermal constant was 184 degrees C/day. Using these results, we determined how long it would take for sugi to be awaken from dormancy and we investigated the meteorological date. Reactivation from dormancy requires 3 days, where the minimum temperature is less than 3 degrees C with a mean temperature of less than 6 degrees C; the following day must have a maximum temperature of more than 10 degrees C, and these conditions must be maintained for at least 2 days. From these results, it is not difficult to predict the day on which sugi pollen scattering will begin.
Taira
H
H
Forest Experiment Station, Toyama Forest and Forests Product Research Center.
Teranishi
H
H
Kenda
Y
Y
D005544:Forecasting; D018521:Plant Physiological Phenomena; D011058:Pollen; D012621:Seasons; D013696:Temperature