Nutrition and Rootstocks to Be Studied

Seventeen researchers have responded to the Citrus Research and Development Foundation’s (CRDF) request for very specific citrus nutrition research, the organization’s board of directors learned May 19. CRDF Chief Operating Officer Rick Dantzler said several advisory groups will review the proposals prior to the CRDF board choosing and funding selected proposals no later than September.

The research requested by CRDF is intended to answer questions that Florida growers have about nutrition. The research will address three issues: nutrient application to soil versus foliar application, the mode of fertilization to the soil, and nutrient impact on fruit quality. Learn some of the history behind CRDF’s intention to answer grower questions about nutrition here.

Several of the nutrition proposals were submitted by University of Florida Institute of Food and Agricultural Sciences researchers, Dantzler said. “We seem to have some really blue-chip growers assisting the researchers with these projects,” he added. He said those grower cooperators are needed “to make sure that trees are being managed properly” and on schedule.

Dantzler also provided information about an in-house CRDF project aimed at learning how some trees on increasingly popular rootstocks are holding up over time. One such rootstock is US-942, which Dantzler said was developed in the 1990s and released to Florida growers around 2010. He said original field trials for the rootstocks were abandoned following their release, but many of the trees still exist. “So we’re starting a project to try to locate where those trees are,” he said.

A CRDF board member suggested it would be a good idea to find the trees and learn how they are doing now, Dantzler said. CRDF staffer Brandon Page is working with rootstock breeders to learn where the trees in the original field trials are located.

“Growers are hoping their trees are going to last longer than 15 years, so we’ll see how these trees do in the long run,” Dantzler said. The project will utilize a machine CRDF helped acquire for another research project. That machine can be moved from grove to grove and grade fruit in the field. Dantzler said it can help determine how much fruit is affected by HLB, among other things.