Keeping Fresh Fruit Marketable

Ernie NeffFresh

fresh fruit
Mark Ritenour

Mark Ritenour with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) discusses research efforts to keep Florida’s fresh fruit marketable. Ritenour is a postharvest horticulturist at the Indian River Research and Education Center.

Ritenour begins with maximum residue limit requirements for chemicals in fresh citrus for export. A UF/IFAS website provides pesticide residue limits by various major export markets. “Even if we’re applying something according to the label rate in that state, our different trading partners can set whatever limits they want,” Ritenour says. “And many of those have set very low ones or lower ones than what we have in the United States … Europe is one of the most notorious” for setting low residue limits.

The maximum residue limit requirements are of concern to both packers and growers, “but really the growers because they’re the ones that are applying and using the materials in the field,” Ritenour says. “So they (growers) need to know what market they’re going to go to, what they’re applying and what those markets allow.”


Several laboratories at UF/IFAS and the U.S. Department of Agriculture are working to develop methods to reduce postharvest decay on fruit, Ritenour says. “With HLB widespread here, we have for some time been getting more decay on our fresh fruit.” Some markets, like Japan, will make the shipper repack the fruit if decay levels are too high, and that’s expensive. Ritenour says scientists are looking at issues from the grove to postharvest in an effort to reduce decay.

Ritenour reports on a new electronic grading unit that should be able to help find HLB-affected fruit. He says an optical unit can detect size, weight, color, blemishes, density and internal Brix content of fruit. “With all of that, we can probably electronically evaluate the quality of that fruit but also how much of it is actually HLB-affected versus asymptomatic, healthy fruit,” Ritenour says.

This interview with Ritenour is featured in the February All In For Citrus podcast, a joint project of UF/IFAS and AgNet Media. Listen to the full podcast here.

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About the Author
Ernie Neff

Ernie Neff

Senior Correspondent at Large