Studies on Corresponded Relations between Plant Characters and Cultivation Methods : II. Growth response of the native millets to the technical differences between direct sowing and transplanting

Abstract

The field works and some experiments in the green house were made to know the growth characters of native millets collected in the mountainous areas such as Chubu, Ryohakusan and Nara Yoshino districts in 1974-1979. In this thesis, the discussion was done from the view point of technical differences between direct sowing and transplanting, and rooting ability was mainly mentioned. The obtained results were as follows: 1. According to the results of field research in relation to the cultivation ratio of direct sowing to transplanting on the millets, the italian millet (Setaria italica Beauv.) and the common millet (Panicum miliaceum L.) are cultivated by direct sowing, generally. On the contrary, the finger millet (Eleusine coracana Gaertn.) and the grain sorghum (Sorghum bicolor Moench.) are mostly transplanted but the japanese barnyard millet (Echinochloa utilis Ohwi et Yabuno) is cultivated about fifty-fifty in the both methods. The following experiments are based on these selective corresponded relationships between cultivation methods and supplied crops in the surveyed areas. 2. Some characters of the used crops were cleared by the field experiment in 1977. That is, the italian millet was subject to damage by transplanting, and the number of tillers produced per plant was also extremely few comparing with others. Therefore, it was seemed that these characters could cause lower yield in the case of transplanting cultivation for this crop. On the other hand, the finger millet was able to perform its growth smoothly after transplanting, besides it could produce a lot of tillers per plant. In addition, it was possible for this millet to have large ears as the general feature of transplanted plants without making less yield significantly than that of direct sowing. The japanese barnyard millet showed intermediate characters of plant growth and grain production between them. 3. The cutting treatment for the plant roots wras made and then the plants were planted under the different soil moisture contents (40%, 60%, 80% soil moisture against the maximum water holding capacity) to grasp the rooting ability of these millets. As a result, it was proved that the rate of the taking root was high in the finger millet and the sorghum, but low in the italian millet and the common millet. Especially, rooting ability of the sorghum was relatively high under the low soil moisture contents and its growth after cutting treatment was also in the better conditions than the others. As to the japanese barnyard millet, it had quite a high rooting ability. From the above results, it is obvious that one of the main reasons why certain millets are able to be transplanted selectively without directly sowing is due to their high rooting ability, and pointed out that the tillering ability is also an important factor to determine the planting method from the standpoint of grains yield.