Improving basil downy mildew control with cultural and biological methods

Project Overview

Project Type: Graduate Student
Funds awarded in 2016: $14,999.00
Projected End Date: 08/31/2017
Grant Recipient: University of Massachusetts Amherst
Region: Northeast
State: Massachusetts
Graduate Student:
Faculty Advisor:
Dr. Robert Wick
University of Massachusetts Amherst

Annual Reports


  • Additional Plants: herbs


  • Crop Production: biological inoculants
  • Pest Management: biological control, cultural control

    Proposal abstract:

    Basil downy mildew is caused by the pathogen Peronospora belbahrii, which results in devastating crop losses for basil growers. Basil downy mildew is not effectively controlled with organic fungicide spray programs, and conventional fungicides are limited and can risk increased pathogen resistance. Our research aims to improve cultural control methods for greenhouse propagation of sweet basil. We will determine how long the basil downy mildew pathogen remains viable and infective so that we can develop a recommendation regarding how soon crops may be re-established in a greenhouse following a disease episode. We will also investigate the efficacy of Pseudozyma aphidis, a filamentous yeast, as a biological control agent. In order to determine this organism’s capability of reducing basil downy mildew infection and spread, we will use disease scoring methods, microscopic examination of the extent of Peronospora belbahrii hyphal infection in sweet basil, and real-time PCR quantification of basil downy mildew biomass reduction resulting from treatment with P. aphidis.

    Project objectives from proposal:

         Our central objective is to discover and communicate information to basil growers regarding the basil downy mildew pathogen in an effort to improve control efforts. Specifically:

    1. Determine the length of time that Peronospora belbahrii sporangia remain viable in order to establish a safe time interval at which time greenhouse basil production can be re-established after a disease episode has occurred
    2. Determine the efficacy of Pseudozyma aphidis applied as a biological control to reduce basil downy mildew infection
    3. Communicate our findings with basil growers and researchers through extension educational programing, fact sheets and the UMass extension web site, as well as professional organization meetings.
    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.