Title:

Identification of morphological markers for the transition to flowering in Kentucky bluegrass as an aid to crop management.

Objectives:

1. Develop maximum genetic and biological potential.
   1. Identify morphological indicators of the juvenile to adult transition and develop a growth stage model for floral competency.
   2. Identify biochemical differences in wax composition.
   3. Compare cultivars that show variation in timing of floral induction and density of tiller production.
   4. Compare developmental changes in tillers before and after mechanical residue removal in the field.
2. Develop sustainable grass seed cropping systems.
   1. Develop a practical means for the grower to assess leaf stage.

Principal Investigator:

Dr. Anne W. Sylvester Developmental Anatomy Biological Sciences, UI

Cooperators:

Dr. Glenn Murray, Agronomist, PSES, UI
Dr. Jeff Griffin, Molecular Physiologist, PSES, UI
Vickie Parker-Clarke, Agric. Ext. Agent, Kootenai County ID
Roecks Farm, Grower, Worley ID
Jacklin Seed Co., Industry, Post Falls ID

Abstract:

Vein anatomy in leaves correlates with the floral transition in Kentucky bluegrass. A heterogeneous assemblage of tillers are described from sod samples of burned and clipped fields. Some tillers emerge in early fall and flower the next summer (at 1 yr old). Other tillers emerge in the fall, do not become vernalized, but flower in their second year. These 1 1/2 yr old tillers develop more productive panicles than 1 yr old tillers. We propose that management practices might incorporate a 2 year cycle into planning, with an emphasis on encouraging the initiation of tillers late in the fall.

Justification:

Mechanical removal of grass residue is currently investigated as the best feasible alternative to open-field burning. Timing of the treatment still appears to be critical to the future productivity of the crop. Regardless of fall treatment, seed production is enhanced only in tillers that have passed a growth threshold, previously termed the juvenile phase. Understanding when this threshold occurs, and what the life cycle is for individual tillers, is essential to the appropriate design of residue management systems. Understanding the biology of the plant will help provide a framework for managing the crop without burning.