Title:

Relationship of Kentucky Bluegrass Cultivars To Mechanical Residue Removal Method and Nitrogen Timing

Objectives:

1. To measure the agronomic performance of five diverse Kentucky bluegrass cultivars to three post-harvest residue removal methods and three timings of nitrogen application.
2. To relate agronomic performance to floral induction and microclimatic measurements to allow prediction of cultivar responses at other locations.

Principle Investigator:

Glen A. Murray, Agronomist and Crop Physiologist UI

Cooperators:

Anne Sylvester Anatomist Biological Sciences UI
John Hammel Soil Scientist PSES UI
Steve Griffith Physiologist NFSPRC*
Vickie Parker-Clark Extension Educator Kootenai Co.UI
Jerry Swensen Support Scientist (Murray) PSES UI
Peggy Lamb M.S. Graduate Student PSES UI
Jacklin Seed Co. Post Falls, ID

Abstract:

Second year seed yields of cultivars varied with respect to timing of nitrogen application. Limousine had the lowest yield when all nitrogen was applied in mid-October. South Dakota, and especially Georgetown, had highest yields when all nitrogen was applied in mid-October. Most cultivars had higher yields with burning, but Baron responded similarly to all methods of residue removal. Glade and Georgetown showed no yield change whether burned or crewcut, but all cultivars showed lowest yields with needlenose raking. Panicle number at harvest time was not related to seed yield.

Justification:

About 100,000 acres of Kentucky bluegrass are produced annually in the Pacific Northwest. Opposition to smoke from burning of post-harvest residue has resulted in a phase out of burning in Washington and may impact production in Washington and Idaho. Nitrogen management is an especially important part of a management system because cultivars respond differently to timing of nitrogen application and to residue removal method. Nitrogen increases vegetative growth and delays flowering in other plants and may delay floral induction in bluegrass. The interaction of cultivar with residue management method and timing of nitrogen application has not been tested.