The project goal is to control cucumber downy mildew in the field using nighttime applications of UV-C. The team will conduct a laboratory study to determine optimum pre- and post-infection doses of UV-C. A trailer suitable for cucumber fields housing UV-C lamps in Northeast will be designed and built to demonstrate the efficacy of pre- and post-infection UV-C applications in the field. We will educate Northeast farmers on the practical application of UV-C treatments.
Question 1: For reducing disease severity from cucumber DM, what dosing regime is the best combination of (a) dose (amount x duration), (b) time of application (pre- or post-inoculation), and (c) interval between dosing (1 per week vs. 2 per week) for nighttime applications of UV-C? (laboratory).
Question 2: Does the efficacy of the best dosing regime increase with UV-reflective material? (laboratory).
Question 3: Is the best dosing regime as effective as conventional fungicide spraying? (field)
Question 4: Is the life-cycle benefit/cost of the UV-C system and dosing regime equal to or less than conventional fungicide spraying equipment and methods?
Due to challenges in laboratory experiments of maintaining the cucumber downy mildew inoculum, we decided it was more effective to evaluate multiple conditions in the field. Currently we are working with Jim Ward (of Ward’s Berry Farm) and Sue Schuefele to design the experiment. This consists of 10 rows, 300 feet long, that will be divided up randomly into blocks and will test varying doses (from 120 – 580 Joules per meter squared, once per week), as well as with and without a UV reflective mulch. Jim explained the row structure and we discussed the possible mulches that could be used and it appeared that Mylar could be used. We are aiming to complete the experimental field design by February, so that plans for planting, building the dragon and field assessments are in place so we can move forward on those items.
The below file summarizes the status of experiments, analysis and plans as of December. As described above, we are currently in the process of finalizing plans for spring and summer.
No updates to report at this time.
Education & Outreach Activities and Participation Summary
We have not yet reached this stage of the project, but do have some materials in development from prior projects that we will be able to utilize and build upon. This includes the website that we maintain, which will contain copies of the build plans and educational materials used for in-person presentations: https://www.lrc.rpi.edu/programs/plants/plants_home.html
We are currently in the process of planning field trials. Outreach activities will begin only after we have obtained field trial results. In the meantime, we are actively participating in workshops to educate farmers on use of UV light for squash powdery mildew and strawberry powdery mildew, but these workshops are not under this sponsorship. We have discussed the value of using UV light for cucumber downy mildew mainly with our farmer collaborators to include Jim Ward, Amy Hepworth, Larry Eckhardt, as well as our extension agent collaborator Sue Schuefele and advisory board members Dr. Meg McGrath and Dr. David Gadoury.