抄録
The authors have studied physiologically on the effects of temperature and photoperiod on development of tobacco plants last years. To get more precise knowledges about the facts, experiments were carried out three times from 1954 to 1956 in air-conditioning greenhouses. Variety tested was Virginia type "Bright Yellow". Results obtained were as follows: 1) It was observed that under relatively low temperatures (8°C∼15°C) development was accelerated raardless day-length but clear changes were shown by day-length under relatively high temperature (18°C∼23°C). 2) Namely, up to 15°C progressive differences were shown with the increase of day-length, but both above 14 hours at 18°C, and above 12 hours at 23°C, discontinuous delay of development was observed. At 28°C, plants tested were all vegetative regardless the day-length. 3) Those facts, described above, suggested that the most suitable temperature condition consisted in 13°C to 18°C and the optimum day length were 8 hrs to 10 hrs in relation to the acceleration of reproductive process of tobacco plants.
