チューリップのボトリチス病防除に関する研究(第1報)

その他

1. Botrytis tulipae was isolated from the tulip bulb in the cultivating field of Naoe-Mura, Hi-kawa District, Shimane Prefecture.
2. Physiological experiment of the fungus is as follows:
a. The measurments of the conidia are 13.5-21×7.5-12 μ, the diameter of the sclerotium is about 1-2 mm.
b. The optimum temperature for mycelial growth is about 20℃.
c. Sclerotial formation was observed in 10°-25℃, and optimum formation was 20℃.
d. On the culture medium, the conidia formation is observed below 10℃.
e. Optimum germination temperature of the conidia was 15℃.
f. Conidia did not germinate below 88% relative humidity.
3. The possibility of the existence of the hyphae in the inner part of tulip bulb, and source of primary infection were suggested.
4. Hot water treatment, as one of the disinfection method, were carried out, and the present fungus died by 41℃ 180 min., 44℃ 60 min., 47℃ 20 min., treatments respectively.
5. Among 15 plots, 48℃ 20 min. treatment gave best result, but the treatment before planting brought remarkable injury to the tulip bulbs.
6. The above mentioned hot water treatments might be carried out in more lower temperatures and shoter period.