Application of Ultraviolet Light and MilStop to Restrict Powdery Mildew Infestation in Vegetable Greenhouses

Project Overview

Project Type: Partnership
Funds awarded in 2022: $28,131.00
Projected End Date: 09/30/2024
Grant Recipient: Rodale Institute
Region: Northeast
State: Pennsylvania
Project Leader:


  • Vegetables: greens (lettuces)


  • Pest Management: integrated pest management
  • Production Systems: organic agriculture

    Proposal abstract:

    Powdery mildew is a destructive fungal disease that affects several species of vegetable crops in controlled environments across the Northeast USA. Greenhouse growers reported that powdery mildew infestation starts in seedling rooms then transmitted to the main growing area causing significant yield and quality loss. Use of non-ionizing Ultraviolet light (UV-light) to control fungal diseases has been considered as an alternative method for conventional pest management approaches, such as, application of chemical pesticides. Antimicrobial characteristics of bicarbonate salts are also well known.

    In this partnership project, we will test an integrated methodology comprised of UV-light radiation and MilStop application to control powdery mildew in organic lettuce (Lactuca sativa) production. We will expose lettuce seedlings to two types of UV-light (UV-C and UV-B) to control powdery mildew before transplanting. Exposure to UV-light will be combined with the application of MilStop, which is a potassium bicarbonate fungicide labeled for using in organic production.

    This project will be conducted through a collaboration between scientists at Rodale Institute and growers at Pocono Organics, Pennsylvania USA. We will evaluate the effect of the proposed techniques on the yield and quality of lettuce, fractional green canopy cover (%FGCC), and density of powdery mildew infestation. The results will help growers to adapt a new integrated pest management approach to control microbial diseases in greenhouses. Research personnel will present the research findings at local and regional meetings, workshops, and conferences. The research results will be also published in the form of fact sheet, bulletin, and research reports.

    Project objectives from proposal:

    This research project seeks to develop an integrated pest management technique to control powdery mildew in organic lettuce production.

     The specific objectives are:

    1. Determine percent reduction in powdery mildew severity on greenhouse lettuce when exposed to UV-lights and MilStop fungicide compared to non-treated control.
    2. Assess the fractional green canopy cover (%FGCC), yield and nutrient quality of greenhouse-grown lettuce treated with UV-light and MilStop.
    3. Establish a demonstration greenhouse with the aim of educating vegetable growers and researchers in the field of crop production and pest management.

    The potential results obtained from this research will help growers to adapt new approaches to control microbial diseases in their vegetable greenhouses. The proof of this proposed IPM method may become a feasible and strong methodology to replace application of chemical pesticides with the aim of improve sustainability in the Northeast agroecosystems.

    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.