Changes in Forage Yield and Composition of Wheat and Wheat-Ryegrass Mixtures with Maturity

Our objectives were to compare wheat and wheat-ryegrass mixtures for patterns of DM accumulation and forage quality changes with maturity. Two genotypes of soft red winter wheat (‘Magnum’ and the hybrid ‘HW 3015’) were grown alone or in mixture with ‘Marshall’ annual ryegrass. Plots were harvested at six wheat growth stages from beginning of pseudostem elongation to soft dough. Handclipped samples were separated into species and leaf and stem (including inflorescence) components, and the components were analyzed for NDF and in vitro DM disappearance. Annual ryegrass in mixture with wheat did not enhance the forage yield over wheat alone; however, the later maturity of ryegrass in relation to wheat resulted in a slower decline in total mixture leaf proportion with advancing maturity than in wheat alone. Enhanced leafiness did not, however, augment total mixture in vitro DM disappearance over that of wheat alone because of the low in vitro DM disappearance of ryegrass stems. If wheat is to be grown for harvest at the soft dough stage for forage, it should not be grown with annual ryegrass, because the latter dilutes the high quality, wheat grain portion with low quality ryegrass stems.