Variations in the Number of Seeds per Unit Weight Among Turfgrass Cultivars1

Abstract Kentucky bluegrass (Poa pratensis L.) and the fine fescues (Festuca rubra L., Festuca rubra var. commutata Gaud. and Festuca ovina var. duriuscula L. Koch) are widely used turfgrasses in temperate regions. Seeding rate recommendations for these species are dependent on seed number per unit weight and are based on counts available in the literature. In recent years, however, breeding and selection have produced cultivars of these species with visible differences in seed size, yet variations in seed numbers have not been documented. This study was conducted to determine seed count variations among several cultivars of Kentucky bluegrass, fine fescue, and among individual lots of Kentucky bluegrass cultivars. Counts for the fine fescues were estimated by calculations made from the weight of 100 seeds. Kentucky bluegrass seed numbers were estimated by the above method and by an electric seed counter. Differences in seed count existed among cultivars of both turfgrasses. Fine fescue cultivars varied from 1,272 seeds/g to 618 seeds/g with a mean for all cultivars of 1,020 seeds/g. Kentucky bluegrass cultivars varied from 4,413 seedsjg to 1,847 seeds/g with a mean of 2,744 seeds/g. Significant differences in seed count were also found to exist among lots of individual Kentucky bluegrass cultivars. Differences among lots as large as 805 seeds/g for ‘Merion’ and 373 seeds/g for ‘Pennstar’ were recorded. Six Kentucky bluegrass cultivars with widely varying seed counts were established on a seed count (308 live seed/dm2) and on a weight basis (0.75 kg/are). This part of the investigation was conducted on a Typic Argiaquolls, Fine‐Loamy, mixed mesic soil at the Ohio State Univ. turf plots in Columbus, Ohio. Initially, cultivars with higher seed counts were established more rapidly than were cultivars with fewer seeds/g, when seeded at the 0.75 kg/are rate. After 6 growing months, no differences in percent cover between either seeding rate or cultivars existed. After 1 year, sod strength determinations were essentially the same among all treatments. If the goal of seeding is rapid establishment, there may be an advantage to seeding Kentucky bluegrass cultivars with fewer seeds/g (larger seeds) at a higher weight/unit area than cultivars with greater seed counts.