Location: Emerging Pests and Pathogens Research
Project Number: 8062-22000-023-019-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 1, 2024
End Date: Jun 30, 2025
Objective:
The overall objective of this cooperative research project is to improve understanding and management of two important potato diseases, known as black dot and Verticillium wilt. These diseases often occur in the same field and are contributing factors in a potato disease complex known as early dying. Although these diseases have been an issue in potato production for years, the way the diseases interact to affect disease severity remains poorly understood. Additionally, some growers have reported increased incidence and severity of black dot without a clear understanding of the root cause, but fungicide resistance may be playing a role. Therefore, this cooperative agreement aims to improve understanding and management of these diseases through the following objectives: 1. Determine the proportion of Colletotrichum coccodes (the black dot pathogen) and Verticillium dahliae (the Verticillium wilt pathogen) recovered from plants showing early dying symptoms; 2. Evaluate sensitivity of C. coccodes to commonly used fungicides; and 3. Determine if co-infections of the two pathogens synergistically increase disease severity compared to each pathogen alone.
Approach:
Symptomatic potato plant samples will be collected by the cooperator and ARS scientists. The cooperator will determine the proportion of each pathogen (C. coccodes and V. dahliae) recovered from plant samples using established quantitative PCR (qPCR) protocols. The cooperator will test samples of C. coccodes for sensitivity to commonly used fungicides in the laboratory using established protocols. ARS scientists will perform co-infection experiments in a growth chamber to determine the relative influence of each pathogen, alone and in combination, on early dying symptoms.
