Varietal Difference of Shattering Habit and Seed Productivity in Guineagrass (Panicum maximum Jacq.) and Panicum spp.

Abstract

Seed shattering, which is a serious economic problem for seed production, is a common feature in tropical pasture plants. To obtain the information on seed shattering, varietal difference of shattering habit and seed productivity were examined in guineagrass (Panicum maximum Jacq.) and several Panicum spp. In guineagrass, the varietal differences in the period from head emergence to shattering-peak and -end were significant, but the varietal difference of seed retention was smaller than interspecific difference. Switchgrass showed the highest seed retention. The varietal differences in seed yield and its components were significant. Estimated seed productivity was calculated from panicle number and seed weight per panicle. The correlation coefficient between seed yield and estimated seed productivity was significant (r=0.676, p<0.05). Multiple correlation coefficient of panicle number per plant and branch number per panicle with seed yield was significant (R=0.836, p<0.05), and the multiple regression equation was shown to be Y=0.022X_1+0.128X_2-2.103, where Y=seed yield, X_1=panicle number per plant and X_2= branch number per panicle. The path coefficient from particle number per plant to seed yield exceeded that of branch number per panicle. This suggested that the effect of panicle number per plant on seed yield was relatively higher than that of branch number per panicle.