Developing a Decision Support Tool for Ventenata IPM in the Inland Northwest

Project Overview

Project Type: Research and Education
Funds awarded in 2010: $169,297.00
Projected End Date: 12/31/2014
Region: Western
State: Oregon
Principal Investigator:
Dr. Timothy Prather
University of Idaho

Annual Reports


  • Agronomic: grass (misc. perennial), hay


  • Animal Production: feed/forage
  • Crop Production: nutrient cycling
  • Education and Training: decision support system, demonstration, extension, on-farm/ranch research, participatory research, technical assistance
  • Farm Business Management: budgets/cost and returns, agricultural finance
  • Pest Management: chemical control, competition, economic threshold, field monitoring/scouting, weather monitoring, weed ecology
  • Production Systems: agroecosystems, holistic management
  • Soil Management: soil analysis, nutrient mineralization


    At the start of our project, the annual grass Ventenata (Ventenata dubia) was not well-known, and certainly its biology was not understood. Our challenge now is meeting the demand for workshops, as recognition and interest in managing Ventenata dubia gains prominence among farmers, ranchers, and land managers. People who participated in the pre-test had some awareness of Ventenata, with 49% having heard about it. Post-test awareness has increased to 66%. The majority of farmers and ranchers who produce alfalfa and grass hay, who have pastures, or who participate in the Conservation Reserve Program consider it a very important problem for their production. Reports from producer meetings suggest that production of grass hay is reduced by as much as 50%, grass stand life is cut in half, and foreign export of infested hay is not possible. Our post-test suggests that overall yields are 20% lower because of Ventenata, it has caused farmers to change their practices, and they are trying a diverse set of methods for control. The regional losses (Eastern Washington and Northern Idaho) are $6.7 million and ripple effects in the economy pose a $22 million negative impact. In addition to economic effects, ecosystem services appear to be impacted, with lower nest success for cavity-nesting birds within CRP. Our respondents of the post-test state that their ability to control Ventenata has not changed, except among people who were not controlling ventenata very well where we saw increases in people who had at least 50% control. We now do have additional methods for management. Farmers are adopting use of herbicides for control in timothy; previously there were no legal options available. We found that farmers have adopted recommendations for fertilization of timothy, and about half of those not using the split timing are considering adopting the technique. Our greatest challenge is convincing farmers that a 4-inch cut height for timothy (currently people cut at 2 to 3 inches) will make their timothy competitive and actually increase yield. In CRP, we see adoption of herbicide application and fertilization as well as use of mowing and herbicide application to stimulate perennial grass production. Fewer people are considering burning for control and those numbers are about 25% considering adoption with 10% adopting the technique. Our project has had considerable success in bettering the livelihoods of farmers and allowing landowners to meet the objectives of the CRP program. We will continue working towards additional solutions and adjusting our decision tool once we have user feedback.

    Project objectives:

    Education EO: Involve stakeholders in production of ventenata IPM using a web-based, decision support tool (DST).


    RO1: Predict ventenata seed germination and seed set using a degree-day model approach.
    RO2: Define impact of ventenata within a whole-farm system nitrogen (N) budget.
    RO3: Determine crop competitiveness (yield) response to alternative management strategies.
    RO4: Determine impact of ventenata on ecosystem services within CRP.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.