Seed Yield, Seed Quality, and Total Establishment Capability of Indiangrass1

Abstract

Relationships between criteria of seed quality and seed yield were studied in indiangrass, Sorghastrum nutans (L.) Nash. Quality and yield criteria also were evaluated as criteria of total establishment capability (TEC), the number of offspring established from seed produced per unit area under given conditions. Quality criteria were: caryopsis weight, seed set, caryopsis percentage, spikelet germination, and percentage of field establishment. Yield criteria were: spikelet yield, caryopsis yield, and number of spikelets per plot of the seed‐productionn ursery. Of the three yield criteria, caryopsis yield correlated most, and numbeorf spikelets, least with quality criteria. All quality and yield criteria were positively associated with TEC. Caryopsis yield was more, highly correlated with TEC than any other criterion not used directly to calculate TEC. Implications of component relationships are discussed in connection with various correlations. In covariance analyses significant seed‐source differences in TEC were generally more attributable to variation in caryopsis yield than to differences in other yield or quality criteria. Caryopsis yield was considered satisfactory as a single criterion of TEC so long as intensive selection for TEC is not anticipated. Where improvement in TEC was a primary breeding objective, however, it seemed hazardous to ignore such quality criteria as spikelet germination and caryopsis weight.