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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Research Project #434849

Research Project: Risk Assessment, Early Detection, and Control of Downy Mildew of Lettuce and Spinach

Location: Crop Improvement and Protection Research

Project Number: 2038-22000-016-25-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Apr 1, 2018
End Date: Sep 30, 2019

Objective:
Determine airborne inoculum load favorable for downy mildew to time fungicide application in a forecast system; examine oospore production, survival, germination and conditions necessary for reproducible infection of spinach; test biopesticides to reduce sporulation of P. effusa on organic spinach; and analyze early infection in spinach leaves (pre-symptomatic) for assessing its utility as a downy mildew disease warning for organic spinach and work with a local company to commercialize the assay.

Approach:
Five or more biopesticide treatments at three separate field plots will be tested to reduce sporulation of P. effusa on organic spinach. Oospore production, survival, germination and conditions necessary for reproducible infection of spinach will be examined in dew chambers and greenhouses, and by microscopy. A field plot will be established with cultivar Viroflay at the USDA ARS location to determine optimal leaf sampling in a small field plot in relationship to early pathogen detection, prior to symptom development. Then DNA polymerase chain reaction approach will be used to determine specific detection of P. effusa in leaves. The amount of DNA in the samples tested may be quantified by comparing this with a known concentration of DNA.