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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Research Project #436500

Research Project: Early Detection, Epidemiology, and Control of Spinach Downy Mildew

Location: Crop Improvement and Protection Research

Project Number: 2038-22000-016-032-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Apr 1, 2019
End Date: Sep 30, 2020

The objectives of the proposed work are to examine P. effusa oospore production and seed transmission, determine airborne inoculum load present at two different periods of the season in the Coachella Valley, California, test Peronospora effusa-specific DNA primers and develop an assay for early detection of spinach downy mildew in leaves, and complete biopesticide testing and analyze a nitrogen dioxide seed fumigation treatment for organic and conventional spinach.

Two or more biopesticide treatments will be tested in an experimental field plot 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 and from spore trap (airborne) samples. The amount of DNA in the samples tested may be quantified by comparing this with a known concentration of DNA.