Date of this Version
Two cross-classified hybrid forage sorghum [Sorghum bicolor (L.) Moench] experiments were conducted at Mead, NE: Experiment 1 (3 females x 8 males), in 1973-75, and Experiment 2 (13 females x 2 males), in 1974-75. Data were collected on plant height, days to bloom, forage yield, percent dry matter (DM), percent protein, and in vitro dry matter disappearance (IVDMD) in both experiments and percent Brix in Experiment 1. Differences among hybrids averaged over females or over males were significant for each trait in one parental group or the other in each test except IVDMD in Test 1 and DM in Test 2. All traits were signficant for hybrid entries in both tests. Interactions of traits with years were often significant and, with the few degrees of freedom in F-tests, contributed to the nonsignificance of yield among females in Test 1 and males in Test 2. Genetic ratios indicated that general combining ability often was relatively high for days to bloom, height, DM, and forage yield; and was of some importance for IVDMD and Brix. Specific combining ability was most important for protein. Correlations among traits indicated that high forage yield often was positively correlated with tall height and late maturity; was negatively correlated with DM, protein, and IVDMD; and was not associated with Brix.