Management of Powdery Mildew in Greenhouse and High Tunnel Tomatoes by Using Ultraviolet C Light

Project Overview

Project Type: Partnership
Funds awarded in 2020: $29,171.00
Projected End Date: 11/30/2023
Grant Recipient: West Virginia University
Region: Northeast
State: West Virginia
Project Leader:
Dr. Mahfuz Rahman
West Virginia University


  • Vegetables: tomatoes


  • Pest Management: integrated pest management

    Proposal abstract:

    Production of vegetables such as tomatoes, cucumbers and peppers in protected environments, like greenhouses and high tunnels, has gained popularity in West Virginia due to proven advantages in extending the growing season and potential of intensive use of scarce flat land. However, due to less wind movement and limited escape of plant-transpired water, these structures are prone to high humidity. This leads to the development of destructive diseases, such as powdery mildew and leaf mold, which are less common in open field production system. Due to the limited fungicidal options for managing diseases in protected culture, plant pathologists have developed alternative management options consisted of non-chemical techniques such as lowering humidity and use of ultraviolet radiation that can make disease management sustainable and reduce cost. This project will primarily focus on control of powdery mildew by exposing tomato plants to required amount of UV-C radiation and examine its efficacy on leaf mold in grower cooperators’ greenhouse and high tunnel. Efficacy of UV-C exposure will be determined with 6 rows of tomatoes, where three rows will receive optimized dose of UV-C and another three rows will be left unexposed to demonstrate the efficacy of UV irradiation to field day attendees (preferably high tunnel and greenhouse growers). The grower cooperators have shown strong interest in conducting trials on site.  Additional outreach activities will include local and regional growers’ meetings and newsletter articles.

    Project objectives from proposal:

    This project seeks to develop a sustainable powdery mildew management method on greenhouse and high tunnel tomato production system by using UV-C light. These UV units can be used repeatedly as and when needed to make it most cost effective, free from environmental pollution and health hazards to workers. This system will make disease management sustainable as the probability of resistance development is very low compared with fungicidal control of powdery mildew. Our objectives are to introduce a new system to the growers and provide them the tips where to get technical cooperation in case they want to get their own UV-C unit assembled and run. This project will capitalize on similar previous work done on multiple crops including tomato, strawberry, cucumber, rose, apple, peach and post-harvest treatment on many different fruits. Specific objectives are:

    1. Assess the usefulness of UV-C light in managing powdery mildew disease in greenhouse and high tunnel;


    1. Optimize the doses, exposure time to attain highest efficacy without any phytotoxicity/avoid damage to plants from light;


    1. Disseminate the technology to organic growers and small farmers through individual communication, grower meetings and conferences, annual field day events, newsletters and cooperative county extension programming.


    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.