Location: Vegetable Research
Project Number: 6080-22000-031-043-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2024
End Date: Sep 29, 2027
Objective:
1. Determine fungicide sensitivity of Phytophthora capsici populations collected cucurbits.
2. Determine the efficacy of drip applied fungicides in combination with foliar fungicide programs for season long protection of watermelon fruit.
3. Evaluate the integration of reduced fungicide programs in combination with Phytophthora resistant rootstock and age-related resistance in squash and pumpkin.
4. Share research findings with growers and industry stakeholders to advance new Phytophthora fruit and crown rot management strategies.
Approach:
The overall objective of this proposal is to develop strategies to manage Phytophthora crown and fruit rot in cucurbits.
Phytophthora crown and fruit rot of cucurbits (crops such as watermelon, cucumbers and squash) is a major problem in cucurbit production. The National Watermelon Association (NWA) has considered Phytophthora fruit rot of watermelon as a top research priority for the past decade. A large collection of Phytophthora capsici isolates (>500) that cause crown and fruit rot in cucurbits has been assembled at the U.S. Vegetable Laboratory (USVL) in Charleston, South Carolina. A sub-set of these isolates will be evaluated in the laboratory in petri-plate assays for sensitivity to various fungicides used by U.S. cucurbit growers. Multi-year field experiments will be conducted at the USVL farm to evaluate the efficacy of drip applied systemic fungicides for managing Phytophthora fruit rot of watermelon. A large 2.5 acre Phytophthora capsici field is located at the USVL farm that will be used for the field studies. USVL has also developed many Phytophthora crown rot resistant rootstocks that will be evaluated for resistance. Results of the studies will be shared with watermelon and other US cucurbit growers through extension publications and presentations at grower meetings. Results of multi-year studies will also be published in peer-reviewed journal for use by the scientific community.
