Studies on the Rice Cultural Practices by Late Transplanting in Cool Region

Abstract

The results of experiments carried out from 1950 to 1958 are reported here conclusively. Lowering of rice yield caused by the delayed transplanting, especially when seeding was made very densely on seed-bed, can be explained as follows: 1) Seedlings are grown to too old, 2) shifting of tillering nodes to upwards, and 3) consequently delaying of tillering and heading takes place. Therefore if the sowing is made lately, or sparsely at the normal sowing date on the nursery-bed, and transplanted lately, the yield can be almost as much as those of the standard culture, because these lately transplanted rice plants can carry on rapid growth and heading does not delayed due to the following reasons; 1) As rice plants have good enough space to grow until the time of transplanting, they can produce many healthy tillers from the lower nodes of their stem. 2) Consequently the larger number of tillers and ears are produced. 3) As tillers from the lower part of the stem appears early, the date of heading is also early and which results in heavy grain weight. After late transplanting, the progress of accumulation and translocation of starch, sugars, total carbohydrates or nitrogen compounds in the plants sown lately or sparsely at the normal date of the plots were found practically not different with standard culture plot.