This study determined the
efficiency of using spaced plants to indirectly improve sward yield and
nutritional quality in tall fescue. Narrow-sense heritabilities,
genetic and rank correlations, and selection efficiencies were estimated from
spaced-plant and seeded-sward evaluation of a tall fescue (Festuca arundinacea Schreb.)
breeding population grown at Logan, UT. Heritability for forage yield
was similar between spaced plants and swards (0.43 and 0.44, respectively), but
genetic correlation between the two was low (0.41). A lack of relationship (r = 0.30; NS) in family ranking between
the two spacings further suggested that spaced plants
were not accurately predicting sward yield. There was moderate agreement
between the spacings for most fiber traits, but a large
discrepancy in heritability and low correlation for crude protein. Direct
selection using swards was always more efficient than indirect selection of
spaced-plants. This was further complicated by relatively low to moderate rank
correlations between spaced-plants and swards. Overall, we concluded that
spaced plant evaluation appears to be less effective at improving sward yield,
and only moderately predictive of sward nutritional quality in tall fescue. New
techniques are needed that maximize genetic expression, but simulate actual
sward production of forage grasses.