Abstract
Investigation were made on the blooming habits of severals pecies of Sorghum, Lolium and Trifolium on a panicle or a head basis. In Sorghum blooming time in a day of the 4n species, Johonson grass, differed distinctively from that of the 2n ones, Sudan grass and seed sorghum, (c.f.Fig.1). In Trifolium species, however, there was little difference. The order of blooming was specific to each genus (c.f.Fig. 2and4), within which there was recognized little interspecific difference. The duration of blooming periods varied with the size of infloresence within a species (c.f.Table 1). A great interspecific variation was observed especially in Trifolium whose species had distinctly different numbers of florets (c. f. Tabel 2), the maximum being 12-14 days in crimson clover and the minimum being 1-2 days in sub clover. The most favorable condition of cultural medium for pollen germination was searched for on some speies of Lolium, Trifolium and Melilotus, with special reference to sucrose and agar concentrations. The sucrose concentration for the highest pollen germination percentage varied evidently among the clover species (c.f. Table 5 and Fig. 6), but not so clearly among the ryegrasses (c.f. Table 4).
