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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #221854
Title: The Effect of Fungicide Applications on Seed Yield in Perennial Ryegrass, and Evaluation of the Rust Model Decision Aid

Author
item MELLBYE, MARK - OREGON STATE UNIVERSITY
item SILBERSTEIN, G - OREGON STATE UNIVERSITY
item GINGRICH, G - OREGON STATE UNIVERSITY
item Pfender, William

Submitted to: Seed Production Research at Oregon State University
Publication Type: Experiment Station
Publication Acceptance Date: 3/31/2007
Publication Date: 4/30/2007
Citation: Mellbye, M.E., Silberstein, G.A., Gingrich, G.A., Pfender, W.F. 2007. The Effect of Fungicide Applications on Seed Yield in Perennial Ryegrass, and Evaluation of the Rust Model Decision Aid. Seed Production Research at Oregon State University. Department of Crop & Soil Science. Ext/CrS P 47-49.

Interpretive Summary: Pacific Northwest grass seed growers spend approximately $15 to $20 million annually for rust control programs, making stem rust the most costly disease problem in Pacific Northwest grass seed production. Severity of rust, and therefore the need for fungicide applications, can differ among fields and from year to year. A model of stem rust is being developed by researchers at USDA-ARS as a tool to help decide if and when sprays are needed. In this experiment, on-farm fungicide trials were conducted at two locations to evaluate the operation of the stem rust model as a decision aid for fungicide applications. Among several fungicide treatment programs at each location was one in which spray decisions were made based on the rust model outputs, derived by operating the publicly- available stem rust estimator webpage. Use of the rust model decision aid indicated application of one less spray than the standard schedule at one site, and two less than standard at the other site. The overall result of using the decision aid in this year was that equivalent yields were obtained with less fungicide at each location. The rust model continues to show promise as a tool growers can use to maintain yields while reducing, in some fields, overall fungicide costs.

Technical Abstract: Field trials were conducted at two locations to evaluate performance of the stem rust model and decision aid that is under development. Among several fungicide treatment programs at each location was one in which spray decisions were made based on the rust model outputs, derived by operating the publicly- available stem rust estimator webpage. Use of the rust model decision aid indicated application of one less spray than the standard schedule at one site, and two less than standard at the other site. Use of the decision aid thus permitted equivalent yields to those in the standard fungicide program, but with less fungicide at each location.