Seeding Grass Species Effects on Grass and Weed Mass in the Year following Renovation with Conventional and Herbicidal Same-day Seeding Methods

Abstract

This paper presents an investigation of grass species effects on the mass of grass and weeds a year after renovation when using a conventional method (COM) and an herbicidal same-day seeding method (HSSM) in the Tohoku region of Japan. Five grass species were examined: perennial ryegrass (PR), kentucky bluegrass (KB), orchardgrass (OG), tall fescue (TF), and meadow fescue (MF). The mass by plant species was measured monthly in April-November. The grass mass tended to be higher in the PR plot than in the MF plot in both renovations. The monthly change in the total weed mass showed a mountain shape that peaked in August-September in both renovations, but the peak magnitude tended to be lower in HSSM than in COM. The HSSM might reduce the weed mass by decreasing bitter dock. The decrease might be a factor that allows the invasion of other weed species depending on the grass species. The difference of weed mass among treatments tended to be PR < OG, TF < KB, MF in COM, and PR, OG < TF, KB, MF in HSSM. Results show that the weed mass was lowest in PR in both renovations. Effects of introducing HSSM are considered to be large in OG.