Sustainable Solutions to IYSV on Onion Via Grower-Research Partnerships

Project Overview

Project Type: Research and Education
Funds awarded in 2008: $177,527.00
Projected End Date: 12/31/2011
Region: Western
State: Oregon
Principal Investigator:
Clinton Shock
Oregon State University

Annual Reports


  • Vegetables: onions


  • Crop Production: application rate management, tissue analysis
  • Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research, participatory research
  • Pest Management: chemical control, cultural control, economic threshold, field monitoring/scouting
  • Production Systems: holistic management
  • Soil Management: soil analysis
  • Sustainable Communities: sustainability measures


    Growers, fieldmen, extension and research personnel cooperated to establish priorities to address Iris Yellow Spot Virus (IYSV) on onion. Trials were conducted by growers, extension and researchers testing varieties, irrigation systems, irrigation criteria, nitrogen fertilizer rates and kaolin clay on IYSV expression, onion thrips and onion bulb yield and quality. Extra nitrogen fertilizer, sprinkler irrigation or kaolin clay failed to reduce IYSV or improve onion yield. More growers adopted drip irrigation, better irrigation scheduling, tolerant onion varieties and more effective thrips control that showed positive responses in grower and station trials.

    Project objectives:

    Maintain onions as a viable part of the PNW family farm crop rotations by reducing the impact of IYSV through the following:

    1) Identify onion lines with resistance or tolerance to IYSV.

    2) Reduce water stress and heat stress on onions through irrigation systems and irrigation criteria.

    3) Determine if added N can help affected onions continue to maintain bulb growth.

    4) Synergism among 1-3 above.

    5) Reduce heat stress by using foliar kaolin clay at peak heat stress.

    6) Demonstrate all useful findings in growers’ fields. Fully and promptly communicate results via word of mouth, field personnel participation, field days, grower meetings, internet, national working group meetings and papers in trade and scientific journals.

    The initiatives of our project would be complementary to initiatives of parallel efforts to control onion thrips and isolate over-wintering seed and bulb crop from the summer bulb crop.

    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.