抄録
In order to make clear the effects of difference in planting time of sugar beet varieties on the bolting tirne, root weight and sucrose percentage, several experiments were carried out, the results being as follows. 1. Most of the easy-bolting varieties planted six times from August 10 to October 20 in Kagawa Prefecture, bolted in the middle of April. But non-bolting varieties as Klein-AA bolted on April 21 and Cesena NSA bolted on May 5. They were planted on September 4. The latter were they planted, the less often they bolted. When those two varieties were planted on October 20, there was found no bolter. 2. In the warm region of Japan as Kagawa Prefecture, cultivation of sugar beet in winter may be successful by using non-bolting varieties as Klein-AA and Cesena NSA and by seeding in September and harvesting before the rainny season of June. Considering from the bolting tendency of these non-bolting varieties the adequate time for harvest should be from the end of April to mid-May. It is very clear that the Italian type of sugar beet cultivation is very difficult to be practised, because of the excess rainfall in June and low temperature in winter in our country.
