Criteria of Field Establishment Capability in Indiangrass, Sorghastrum nutans (L.) Nash 1

Spikelets harvested in three successive years from 21 polycross progenies of indiangrass, Sorghastrum nutans (L.) ‘Nash,’ were evaluated for germination, greenhouse seedling emergences, eed set, caryopsis weight, and ability to establish plants in the field. Field establishment was more consistently associated with spikelet germination prior to dormancy‐reducing treatment than with any other trait. Mean greenhouse seedling emergence from 51mm provided the best approximation of mean field establishment, but as an indicator of relative progeny establishment capability, greenhouse emergence was less satisfactory than spikelet germination. Variation in spikelet germination prior to dormancy‐reducing treatment satisfactorily accounted for significant progeny differences in establishment within each of the three harvests. When data from all harvests were combined, however, differences in establishment among progenies could be satisfactorily explained only by variation in both spikelet germination and caryopsis weight. A possible effect of seeding date upon the relationship between caryopsis dormancy and field establishment was noted. Importance of seed processing in studies of the relationship between field establishment and seed traits was emphasized.