Some leading Kaki varieties, especially “Fuyu”, have no male flower, and rarely set by parthenocarpy. To ensure the fruit set of such varieties, hani pollination method is recom-mended in Japan. This experiment was perfomed at Okitsu Hort. Exp. Sta. to ascertain the most effective method of hand pollination.
1. Before the male flowers open, the branches must be protected by paper bags, lest pollen grains shoud be dispersed.
2. The time when petals and anthers open has varied with varieties of the trees and with climatic conditions. Almost all flowers have opened in the morning, when it was fine wea her and the anthesis took immediately after that.
3. Without any paper bag protection, we can gather pollens easily, as followes: Gather the buds which are expected to open next morning, in the evening of previous day, when they do not bloom at all and preserve them next room. Anthesis will occur at about ten o'clock in the next morning.
4. The fertilizing, ability of the pollen grains, gathered as mentioned above, was examined by means of germination test and pollination test, and proved to be complete. Stored pollens holded practical ability within about five days in room temperature, while lower temperature (_??_°C) and dry condition were preferable, and higher temperature (30°C) was injurious.
5. Two hand pollination methods prevailing in Japan were compared in this study: One is to pollinize by means of writing brush with previously gathered pollens and other to pat the female flowers with male flowers of which petals are removed previously.
6. Pollen quantities were compared among several varieties. “Zenjimaru” had most profuse pollen per flowers.
7. In “Fuyu” variety more than 95 per cent of flowers has set by hand pollination un_??_il the color of petals changed to brown from cream-colored, that could be easily discriminative.
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