Title:

Chemical Renovation and No-Till Annual Cropping to Extend Seed Production Cycles of Kentucky Bluegrass

Objectives:

1. To evaluate spring applied glyphosate, sethoxydim, and glufosinate as chemical suppressors of Kentucky bluegrass to allow no-till planting of annual crops.
2. To evaluate spring wheat and lentils as potential crops during the renovation period.
3. To evaluate variety suppression and subsequent grass seed yield after harvest of annual crop.

Principle Investigators:

Dr. Glen A. Murray
Plant, Soil, & Entomological Sci., University of Idaho

Donald C. Thill
Plant, Soil, & Entomological Sci., University of Idaho

Cooperators:

Grass growers in Idaho and Eastern Washington

Abstract:

Funding for this project received in August, 1996. Bluegrass trials with 16 cultivars that were crewcut for three years, 1993, 1994, and 1995 will be used for these studies. Agronomic performance and floral induction were measured for 1993, 1994, 1995, and 1996 seed crops.

Following harvest of the 1996 seed crop in July-August, the experimental area was again crewcut.

Justification:

About 100,000 acres of Kentucky bluegrass are produced in the Pacific Northwest. A phase out of burning in Washington and opposition to smoke may reduce acreage of bluegrass. Seed yield declines as stands age, with some cultivar yields declining more rapidly than others. High stand density may be partially responsible for yield decline, especially when post-harvest residue is removed mechanically. Stand suppression and thinning with spring applied herbicides may renovate seed yield. No-till planting of annual crops in suppressed bluegrass stands may allow economic return during renovation. Herbicide choice and bluegrass cultivar response to chemical renovation are not adequately known.