Update on Grapefruit Nutrition

Ernie NeffGrapefruit, Nutrition

Johnny Ferrarezi

University of Florida Institute of Food and Agricultural Sciences researcher Rhuanito “Johnny” Ferrarezi reports on research leading to fertilizer recommendations for grapefruit, especially in the Indian River area. Grapefruit has been especially hard hit by HLB, the devastating citrus disease discovered in Florida in 2005.

“We are entering the second season (of the research project) and we hope to have information about better tree density; where to apply the nutrients, in the soil or through foliar nutrition; and we are also working with different rates,” says Ferrarezi, who works at the Indian River Research and Education Center in Fort Pierce. The research is an effort to help growers “decide how to manage the trees in the field and perhaps extend their grove’s life in order to maximize their yields,” he says.

According to Ferrarezi, research has already shown that “the increase in nutrient concentration has a direct relation with the amount of nutrients present in the leaves.” So researchers are increasing zinc, boron and manganese and are seeing a response in leaf nutrition.

“We are looking forward to get the results showing an increasing yield,” Ferrarezi says. “That’s our main goal.” However, he notes that citrus trees can take a long time to get a response in yield.

Ferrarezi was summarizing a report made by one of his graduate students at the recent Florida State Horticultural Society annual meeting in Maitland. 

Hear more from Ferrarezi:

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About the Author

Ernie Neff

Senior Correspondent at Large