Diagnosis and Management of a New Disease of Cucurbits in Oregon

Project Overview

Project Type: Research and Education
Funds awarded in 2015: $145,291.00
Projected End Date: 12/31/2017
Region: Western
State: Oregon
Principal Investigator:
Oregon State University

Annual Reports


  • Vegetables: cucurbits


  • Crop Production: crop rotation, irrigation, varieties and cultivars, water management, winter storage
  • Education and Training: extension, on-farm/ranch research, participatory research, workshop
  • Pest Management: genetic resistance


    Winter squash is grown in the Willamette Valley of Oregon for fresh market sales and as a processing crop for pie filling and confectionary seed. However, a soilborne disease is reducing yield and quality of both fresh market and processing squash. The overarching goal of this project is to increase the economically viable production of winter squash and confectionary seed. This project will work towards that goal by diagnosing squash wilt and root and crown rot, identifying resistant/tolerant varieties, and evaluating the efficacy of crop rotation, fungicides, and other management strategies.

    This project will engage farmer participants and other farmers throughout the course of the project. Field trials will be conducted on participating farm fields. Field tours will be conducted each fall. Project findings will be presented at the N. Willamette Hort Society Vegetable and Organic Days, the Oregon Processed Vegetable Annual Meeting, and the OSU Small Farms Conference. Farmers and buyers will interact with whole and cut squash at interactive conference booths each winter.

    At least 200 farmers have learned about this disease complex through project outreach activities. These farmers have learned about the symptoms, pathogens and the effect on squash yield. They are also learning to diagnose and scout for the disease. Some farmers grew Tetsukabuto, a resistant variety, in 2016. They liked the field, storage, and culinary performance of this less susceptible variety. However, most cucurbit species and varieties have little resistance. Cucurbita maxima germplasm with resistance was identified for use in breeding resistant germplasm with market potential. Rotation (out of all cucurbits) will be an important strategy for the management of this disease, as is true for most soilborne disease caused by pathogens of limited host range. As farmers learn about the disease and its yield implications, and scout for it on their farms, they are considering how to implement longer cucurbit rotations. Some project farmers planted 2016 squash crops on ground with no history of cucurbit production. Fungicides will not be an effective management strategy for this soilborne disease complex.

    Project objectives:

    Objective 1) Engage project farmers in project development, delivery, evaluation, and outreach

    Objective 2) Identify causal agents of squash wilt and root and crown rot

    Objective 3: Identify squash cultivars with resistance or tolerance to squash root and crown rot/wilt, as well as good yield and long shelf life

    Objective 4: Evaluate the efficacy of crop rotation

    Objective 5: Evaluate the efficacy of available fungicides

    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.