Biofumigation for soil health in organic high tunnel and conventional field vegetable production systems

Project Overview

Project Type: Research and Education
Funds awarded in 2006: $170,000.00
Projected End Date: 12/31/2009
Region: Southern
State: Kentucky
Principal Investigator:
Dr. Michael Bomford
Kentucky State University

Annual Reports


  • Agronomic: canola
  • Vegetables: beets, cabbages, carrots, cucurbits, greens (leafy), onions, peppers, tomatoes


  • Crop Production: continuous cropping, cover crops, organic fertilizers
  • Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research
  • Farm Business Management: whole farm planning
  • Pest Management: allelopathy, biological control, botanical pesticides, integrated pest management, mulches - killed, mulching - plastic, soil solarization, mulching - vegetative
  • Production Systems: holistic management
  • Soil Management: green manures, organic matter, soil analysis, soil quality/health

    Proposal abstract:

    This project will test biofumigation – a soil-borne disease management strategy using natural chemicals from brassicas – as a control for two broad-spectrum soil-borne diseases that each pose a severe challenge to a different emerging vegetable production system. The fungus Sclerotinia sclerotiorum thrives in cool conditions, and attacks most of the crops grown in a system developed by Kentucky growers to produce organic vegetables year-round in solar heated high tunnels. Another fungus, Phytophthora capsici, spreads in warm weather and attacks many of the crops grown by the increasing number of farmers switching from tobacco to field vegetable production in our region. We hypothesize that biofumigation could be adapted to both the high tunnel and field vegetable system to manage these diseases while building soil organic matter and enhancing soil microbial activity. We propose a series of laboratory studies to identify promising biofumigant crops for each disease, followed by on-farm field trials adapting the biofumigation strategy to each system. The proposed research responds to specific emerging disease threats and addresses two of the most important research topics identified by local growers in a survey distributed at a recent SARE-funded workshop.

    Project objectives from proposal:

    1. Identify brassica varieties that inhibit survival and growth of S. sclerotiorum and P. capsici in lab-based bioassays. 2. Determine the potential of brassica residue incorporation and solarization – alone and in combination – to reduce disease pressure from S. sclerotiorum and build biologically active soils in high tunnels used for year-round vegetable production. 3. Determine the potential for brassica and non-brassica winter cover crops to reduce disease pressure from P. capsici and build biologically active soils in field vegetable production systems.

    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.