Abstract
Effects of the various treatments on reducing the temperature and the light requirements for germination of Japanese lawn grass (Zoysia japonica Steud.) were studied in some detail following the previous papers. In the first experiment, diverse germination responses corresponding to the treatments employed and the germination conditions prepared were demonstrated (Fig.1). In the next experiment, interrelations between duration of chilling period and kind of the chemical treatments combined were also clarified concerning the regulation of germination responses (Fig.2). Some important facts verified from these experiments were: 1) the combined chemical treatments, NaOH+(GA_3+KNO_3), for adequately chilled seeds-a prescription which has previously been given by the author tentatively-were the most favorable in their effects on acceleration of germination, 2) the same effects as those described above, on the other hand, were obtainable even by NaOH treatment alone, when the seeds were chilled as long as about 90-day period instead of the 30-day's. Besides these experiments mentioned above, some additional problems concerning the effects. of drying to prevent the loss of vigor in prolonged chilled seeds, and the variations in the effects of the treatments due to the differences of the origin of seed populations were examined. Finally, the ecological significances in application of these treatments were briefly touched upon.
