Title:

Diseases in Dryland and Irrigated Cropping Systems without Grass Burning

Objectives:

1. Evaluate diseases of dryland and irrigated grass seed production areas to determine those most serious under thermal and non-thermal residue management systems.

2. Determine cultural and chemical disease control options that are economically and environmentally acceptable for sustainable agricultural production to growers and an environmentally sensitive public.

Principal Investigators:

W. J. Johnston, Assistant Agronomist, WSU
J. W. Sitton, Plant Pathologist, Seed Technology Lab., WSU

Cooperators:

R. J. Cook, Research Plant Pathologist, USDA-ARS, Pullman
M. Mazzola, Research Plant Pathologist, USDA-ARS, Pullman
R. F. Line, Research Plant Pathologist, USDA-ARS, Pullman
S. Wyatt, Assoc. Professor, Plant Pathology, WSU, Pullman
S. Clement, Research Entomologist, USDA-ARS, Pullman
S. Alderman, Research Plant Pathologist, USDA-ARS
P. Peterson, WSU Cooperative Extension, Spokane County

Abstract of 1995 progress:

In 1995, we determined that under non-burned, irrigated management, ergot, silver top, and rust were the most important diseases that limited grass seed yield and quality in eastern WA and north ID. Ergot and foliar diseases were generally less important under dryland management. Generally, mechanical residue removal techniques reduced the severity of ergot and silver top, but were less effective in reducing rust. Field trials with fungicide (Tilt 3.6E) and surfactant (Sylgard 309) applications at pre-anthesis and mid-anthesis were effective in reducing the severity of ergot. This research in part led to the labeling of Tilt for ergot reduction in Kentucky bluegrass seed fields. Growers have reported success with this new ergot control program.

Justification:

The grass seed industry has used open-field burning as a simple, inexpensive and effective means to control a broad spectrum of grass diseases. The question is, can we maintain grass seed yields, control diseases and insects, with minimum input, without grass burning? Also, investigators differ in their assessment of which diseases in grass seed production fields are most serious in the Pacific Northwest. A disease assessment is "key" to developing control options in absence of open-field burning. Once the important organisms have been identified, disease control options will be investigated.