Abstract
We found that the place of the worst climatic condition for the cultivation of aquatic-rice in Japan is Otoineppu, Hokkaido. Here, the sowing time is 15th May and the diurnal minimum air temperature at the sowing time is 2.3°C, while the harvest time is 15th the October and the diurnal, minimum air temperature at the harvest time is 3.2°C.
Therefore, we sought for the places in Japan where the diurnal. minimum airr temperatures are same as those of sowing and harvest time in Otoineppu, and thus we obtained the distribution of theoretical earliest sowing time (Fig. 1) and the maximum cultivating time (Fig. 2) in Japan.
