Abstract
This experiment was conducted to investigate the differences among grasses in the growth of primary tillers in early stage after their appearance. Grasses used were tall fescue, cv. Kentucky 31, orchardgrass, cv. Frode, and Italian ryegrass. The plants were grown at 12°, 20°, and 28℃ under long and short daylengths, respectively. The results are summarized as follows. (1) Number of leaves of primary tillers and rate of increase in the number were largest in orchardgrass, followed by those in Italian ryegrass and those in tall fescue were smallest. (2) Fresh weight of tops of primary tillers was largest in Italian ryegrass at 12℃ and 20℃, while at 28℃ in orchardgrass. That in tall fescue was smallest at all the temperatures tested. Increase in number of secondary tillers in Italian ryegrass was more remarkable than that in tall fescue or orchardgrass. These results indicated that the growth of tops of primary tillers, as shown by the fresh weight and the number of secondary tillers, was most remarkable in Italian ryegrass, followed by that in orchardgrass and that in tall fescue was not remarkable. (3) The growth of roots of primary tillers, as shown by fresh weight, number and length were most remarkable in Italian ryegrass, followed by that in orchardgrass and that in tall fescue was not remarkable. From the results mentioned above, it was shown that ecto-morphological form of primary tillers in Italian ryegrass was established early, followed by that in orchardgrass and that in tall fescue was latest. It may be suggested that time of independence of tillers from main stem differs with grasses.
