Determination of high-risk seeding times for Kentucky bluegrass, tall fescue, and perennial ryegrass when established in autumn at LAT 40 degrees midwest, USA

Autumn, spring, and summer seeding schedules have been recommended for turf reestablishment. Dormant seeding is a practice that is often used when renovating football fields at the end of the playing season. Early seeding in autumn guarantees germination and establishment before the season ends. Very late seeding during autumn usually means no germination; plants do not develop until the following spring. Seeding in the middle of autumn may actually be inefficient due to poor germination and lack of time to develop winter hardiness. The purpose of this research is to determine high-risk seeding dates of turfgrass species for football activities. This study was established at the Horticulture Research Farm in Ames, Iowa USA, on 26 Sept. 2003 and on 1 Oct. 2004. Three species of turfgrass, Kentucky bluegrass (Poa pratensis L.) (KB), perennial ryegrass (Lolium perenne L.) (PR), and tall fescue (Festuca arundinacea L.) (TF) were evaluated. Seeding for year 1 occurred on 26 Sept., 3 Oct., 10 Oct., 17 Oct., 31 Oct., 14 Nov., and 28 Nov. 2003 and 22 Apr., 13 May, and 3 June 2004. Year 2 seeding dates were I Oct., 8 Oct., 15 Oct., 27 Oct., 15 Nov., 29 Nov. 2004, and 15 Apr., 15 May, and 15 June of 2005. Seeding rates were 10 g.m(-2) of KB and 50 g.m(-2) of PR and TF. Turfgrass cover was evaluated before each seeding date and on 29 June of 2004 and 12 July 2005. During the first year, the 17 Oct. seeding date produced the least amount of turf cover by the following summer on 29 June. In the second year least turf cover in 12 July was produced when TF, PR and KB, were seeded on 27 Oct. and 15 and 29 Nov., respectively. To obtain 50% turf cover by the end of the autumn growing period, KB at 10 g.m(-2) has to be seeded by 31 Aug., TF at 50 g.m(-2) has to be seeded by 7 Sept. and PR at 50 g m(-2) has to he seeded by 1 Oct. A high-risk period when autumn seeding should be avoided could not be determined, however seedings on or before 15 Oct. always yielded over 70% turf cover during the next summer.