Abstract
In order to estimate the changes in dry weight of regrowth with the development of stage and to clarify its mechanism, 8 species of grass were defoliated at several stages of development, and kept in phytotron for 3 weeks under fixed temperatures for each species. It was found that the changes in dry weight of regrowth with the development of stage, differed in species of grass, and could be classified into four patterns. 1) The dry weight of regrowth decreased with the development of stage. (oats, Italian ryegrass) 2) The dry weight of regrowth decreased at heading and ripening stage, and was great before and after these stages. (perennial ryegrass, timothy, orchardgrass, Rhodesgrass) 3) The dry weight of regrowth increased with the development of stage. (bahiagrass) 4) The dry weight of regrowth increased at middle period of growth, and was small before and after this period. (Dallisgrass) It was shown that the dry weight of regrowth was decided by both dry weight of root and stubble at the defoliation and rate of regrowth. And in case of this experiment, the changes in dry weight of regrowth with the development of stages were affected mainly by the rate of regrowth.
