抄録
1. Experiments were carried out in order to clear the varietal difference of the effects of day length on the root development in the rice seedlings, by means of water culture in the test tube. 2. Results obtained were summarized as follows: In the case of 24 hrs. Day-length, number of roots and weight of dry matter of both root and top increased in the short day variety, on the contrary, there was no increment in the day-nertral variety. (Table 1, 2 &3.)
