Varietal Differences in Effects of Deeper Topdressing on the Growth and Yield of Rice Plant in Wakayama Pref. Japan

本研究の一部は, 近畿大学研究助成金を受けて行なった。This experiment was conducted on paddy field of the Agricultural Experiment Farm of Kinki Univ. in Yuasa, Wakayama Prefecture. It is the purposes of this experiment to obtain the data to be useful for establishing fertilizer application method in practical cultivation of the five rice varieties in this region, and to clarify the varietal differences in the effects of deeper topdressing on these rice varieties. The following results were become evident after this experiment. 1. In case of practical cultivation of extremely early maturing variety; Koshihikari, in spite of fertilizing methods it is necessary to advance the planting time for a stable yield increase. 2. Varietal differences of effects of deeper topdressing on the change of LAI were not recognized in this experiment. 3. The effects of deeper, topdressing on the yield were showed in the weight of a head which increased in all varieties used in this experiment, and therefore the results suggest that deeper topdressing generally becomes a very useful method to recommended rice variety in warm temperate zone of Japan