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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Research Project #438116

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

Location: Crop Improvement and Protection Research

Project Number: 2038-22000-016-42-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Apr 1, 2020
End Date: Mar 31, 2021

Objective:
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 versus the Salinas Valley, California; evaluate whether a weedy plant species located near spinach fields can serve as a reservoir for spinach downy mildew, and complete biopesticide testing and analyze a nitrogen dioxide seed fumigation treatment for organic and conventional spinach.

Approach:
Oospore production, survival, germination and conditions necessary for reproducible infection of spinach will be examined in dew chambers and greenhouses, and by microscopy. Two or more biopesticide treatments will be tested in an experimental field plot to reduce sporulation of P. effusa on organic spinach. 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. Evaluations of whether a weedy plant species located near spinach fields can serve as a reservoir for spinach downy mildew will be carried out by doing cross-inoculations of the pathogens on both spinach and the weed host in growth chambers and humidity tents.