Abstract
1. The author presents the fluctuation curve of ears per tsubo of paddy rice varieties, tested by all the Prefectural Agricultural Experiment Station in Japan. The investigated case number exceeds 38, 000. And by that curve the minimum is about 200 ears per tsubo, mode is 900, mean is 859, maximum is about 1, 900, and the σ is 214.9. The center of the gravity of the curve inclines to the left a little. 2. We can calculate the accumlated number of ears per tsubo, and exhibit it by a cumulative curve. By that curve we conclude that the varieties over the half of the varieties of Japanese paddy rice have minor ears than 815. And the case that the number of ears per tsubo exceeds 1, 200, about which many agriculturists say that rice shows a good yield, is very rare and its percentage is smaller than 5%. 3. The author explained the mean ears per tsubo of every Prefectural Agricultural Experiment Station. And the prefectures having lesser ears are as follows, Mie, Shiga, Osaka, Tochigi, Nara and Tottori. And the prefectures having more ears are as follows ; Fukui, Kumamoto, Yamagata, Ishikawa, Akita, Yamaguchi and Aomori. 4. The author explained the mean ears per tsubo of many varieties. And the varieties having lesser ears are as follows ; Kokuryomiyako, Watarifune, Hokoku, Fukusin, Showa No. 2. And the varieties having more ears are as follows; Norin No. 6, Sakae, Kyushu No. 8, Senbon Asahi and Norin No. 1. 5. The author shows the varietal, and the local, correlation coefficient of ears per tsubo and other characters. 6. As an appendix of this investigation the author explained the varietal correlation coefficient and the local correlation coefficient, and the yearly correlation coefficient of ears per plant with other characters.
