Management of Soil-borne Plant Parasitic Nematodes for Sustainable Production of Field Grown Tomatoes and Cucumbers by Cover Cropping

Project Overview

Project Type: Research and Education
Funds awarded in 1997: $21,900.00
Projected End Date: 12/31/2001
Matching Non-Federal Funds: $10,500.00
Region: Western
State: Hawaii
Principal Investigator:
John McHugh
Waikele Farms

Information Products


  • Vegetables: cucurbits


  • Crop Production: cover crops, fallow
  • Education and Training: extension
  • Farm Business Management: feasibility study
  • Pest Management: biological control, chemical control, field monitoring/scouting, mulching - vegetative
  • Production Systems: general crop production


    [Note to online version: The report for this project includes tables that could not be included here. The regional SARE office will mail a hard copy of the entire report at your request. Just contact Western SARE at 435-797-2257 or]

    A field study was conducted to evaluate the effectiveness of cover cropping as a sustainable pest management tool for root knot and reniform nematode control in commercial vine ripe tomatoes. Treatments were Bare Ground Fallow (6 month fallow), soil fumigation with Metam Sodium (industry standard) and two cover crops: Sunn Hemp (Crotolaria juncea) and Yellow Mustard (Sinapsis alba). Cost effectiveness of all treatments was also examined. The experiment was conducted twice. The first test was completed on October 31, 2000, the second test finished on August 31, 2001. Root knot nematode levels were low in the first iteration of the study so all plots were inoculated with root knot nematode contaminated soil for the second trial. There were no statistically significant yield differences between treatments in the first or second iterations of the trial. Though not statistically significant, tomato yields were consistently higher in Sunn Hemp plots compared to Yellow Mustard and Bare Ground Fallow during both study periods (10 – 30% higher). Root knot and reniform nematode infestation was high during the second trial period but no statistically significant effect of cover cropping on root knot nematode reduction was detected although numbers for both species of nematodes were lowest in Yellow Mustard and Sunn Hemp in the trial ending August 31, 2001. The effect of the number of root knot nematodes on yield was statistically significant and yield generally declined as root knot nematodes increased. The best dollar return per acre was Sunn Hemp with a gross margin of $11,787.88 compared to the industry standard treatment of Metam Sodium soil fumigation at $10,926.94. Information regarding this research was disseminated to the community (ag and general community) by publicized field days (television, radio, print media, and University of Hawaii Cooperative Extension Service) held on January 6, 2001 and June 30, 2001.

    Project objectives:

    1. Determine the effectiveness of selected cover crops in reducing and/or controlling plant parasitic nematodes in commercial tomato fields.
    2. Determine the economic feasibility of using this control tactic within an existing tomato farming operation.
    3. Share the information obtained with tomato growers in the state via University of Hawaii extension personnel and publications.

    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.