Evaluation of Seeding Rates of AU Triumph and Endophyte-Infected Kentucky 31 Tall Fescue

Abstract

Increased difficulty in stand establishment of tall fescue (Festuca arundinacea Schreb.) has been reported by producers since the introduction of endophyte (Acremonium coenophialum Morgan-Jones and Gams)-free tall fescue seed into the market place. This has encouraged the use of higher seeding rates for endophyte-free tall fescue without scientific basis. The objective of this study was to determine whether ‘AU Triumph’, and endophyte-free cultivar, and endophyte-infected ‘Kentucky 31’ differ in minimum seeding rates for successful establishment. Experiments were established at two locations in each of two years, using a randomized complete block with four replications. Soils at the two locations were Cahaba fine sandy loam (fine-loamy, siliceous, thermic Typic Hapludult) and Sumter clay (fine-silty, carbonatic, thermic Rendollic Eutrochreps). For a period of 17–19 mo after planting, dry matter yields were determined whenever forage reached approximately 6 in. in height. Each location × year combination was analyzed independently. Linear and quadratic effects of seeding rate were tested at each harvest date, and single degree of freedom comparisons were made for cultivar effects and their interactions with the linear and quadratic effects. At harvest dates when significant linear or quadratic effects were detected for seeding rate, response curves were fitted. In some juvenile stands (first or second post planting harvests), dry matter yields increased with increasing seeding rates, or increased with increasing seeding rates to approximately 20 lb seed/acre and then leveled off. Seeding rates did not affect tall fescue yields at later harvests. Lack of cultivar interactions with seeding rate indicates there is no basis for recommending higher seeding rates of AU Triumph than for endophyte-infected Kentucky 31 under these conditions.