Abstract
The present study was carried out in 1963 to obtain some information on the germination of coated rice seeds, using the variety "Tosan No. 38" as material. The seeds were dried in the air after pregermination treatment in the water and were coated with following seven kinds of materials; Pearlite, Vermilite, Volcanic ash soil, Soiluck, Primary calcium phosphate, Hepta-dust and Atonic. In the first experiment, the filter paper was used as seed beds in 9 cm Petri-dishes and the water quantity of seed beds was conducted with next five degrees containing 3, 5, 8, 15 and 30cc. In the second experiment, the soil was used as seed beds in 9 cm Petri-dishes and the water quantity of seed beds was conducted with next seven degrees containing about 42, 52, 63, 73, 83, 94 and 104% of water capacity. The third experiment was also carried out to investigate the germination and early growth in the coated seeds under the different conditions of five types of seeding. The results obtaintd are as follows: 1) In the case of first experiment, the coated seeds germinated most quickly in 3 cc plot, but in other plots were inferior to the non-coated seeds. 2) In the case of second experiment, the coated seeds showed a tendency of earlier germination and development in below 73% plots than those in the non-coated seed plots. At the same time, the limit of water quantity in seed beds for the appearance of plumules or radicles in the coated seeds was about 90% of water capacity as well as in the non-coated seed. 3) As to the third experiment, in the direct seeding under the dry field condition, the appearanec of plumules and their growth in the coated seeds were superior to those of non-coated seed. While there was no great difference between the coated and non-coated seeds under other seeding conditions. 4) Judging from the results obtained, the coated rice seeds seem to be useful in the direct seeding at the dry field. Moreover, it may be possible to expect better effects by research and improvement in the future.
