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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Commodity Protection and Quality Research » Research » Research Project #434847

Research Project: Maintaining Market Access for California Citrus to the Australian and South Korean Markets

Location: Commodity Protection and Quality Research

Project Number: 2034-43000-040-56-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Apr 25, 2018
End Date: Sep 30, 2019

To ensure that efficacious postharvest treatments of citrus using phosphine fumigation do not harm fruit quality.

California citrus of various types (navel and Valencia orange, lemon, mandarin and grapefruit) will be treated with 3 exposure times (12, 24 and 48 hours) to phosphine (1,000 ppm) at 41F to compare the potential for phytotoxicity to an untreated control. Methyl bromide fumigation will be included as an additional control for comparison. Three tests will be conducted per citrus type bracketing the export season for each type (early, mid and late season). Three grower lots will be evaluated in each test. Fruit will be obtained within 12 hours of packing from commercial packinghouses in California. The control fruit will be immediately stored at the appropriate temperature for the particular citrus type. Phosphine will be applied at 41F for the different exposure times and then fruit stored. Methyl bromide treatments will be applied following simulated storage/transit. All fruit will be evaluated following a “market” simulation at 68F. Fruit will be evaluated for external quality, soluble solids content, titratable acidity and decay. A subsample of fruit will be evaluated by a semi-expert panel for visual and eating quality.