When to Be on Canker Alert

Ernie NeffCitrus

canker
canker
Megan Dewdney

Citrus fruit is susceptible to canker after it reaches three-eighths of an inch in diameter, University of Florida Institute of Food and Agricultural Sciences Extension pathologist Megan Dewdney told growers this winter.

“Once you get to that point and we get rain, then all bets are off as to whether you will keep canker out,” Dewdney said at a winter disease seminar in Immokalee. “So you do want to get those fruit protected as soon as they’re getting up to that size … Those first few sprays are particularly critical because of the high susceptibility of the fruit. Those are the lesions that will knock most of the fruit off.” She recommended spraying with copper at 21-day intervals.

Dewdney reported that Hurricane Irma in the fall of 2017 exacerbated the disease in Florida. “It (Irma) intensified what we had out there already,” she said. “Young blocks that didn’t necessarily have much canker in them certainly became highly infected.”

In closing, Dewdney said, “Everybody should keep it (canker) in mind when planning their programs for the year.”

The seminar Dewdney addressed was hosted by multi-county citrus Extension agent Mongi Zekri at the Southwest Florida Research and Education Center.

Hear more from Dewdney:

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Ernie Neff

Ernie Neff

Senior Correspondent at Large