FORT PIERCE, Fla.—Ricardo A. Lesmes-Vesga aims to develop peach rootstocks specific to Florida’s different production regions. The findings will lead to new rootstocks for growers who harvest the fruit when the crops are the nation’s sole source for fresh peaches.

Lesmes-Vesga is a Ph.D. candidate at the University of Florida Institute of Food and Agricultural Sciences Indian River Research and Education Center (UF/IFAS-IRREC) in Fort Pierce. His graduate research program is to phenotype peach root systems in Florida’s different soil regions. Peaches grow on about 2,000 acres in Florida. Lesmes-Vesga’s work is overseen by scientists who have expertise in economics and grower relations, plant breeding, and plant root biology.

Florida peaches are available to consumers in mid-March, well ahead of traditional peach growers in Georgia, and through mid-May. The advantage to growers is that they will meet the need when peaches are available only from Florida growers. One of Lesmes-Vesga’s graduate advisors, Ali Sarkhosh, an assistant professor of tree fruit and viticulture with the UF/IFAS Horticultural Sciences Department in Gainesville, works closely with all of the state’s peach growers.

“Ricardo’s research will help peach growers select the correct rootstocks for the soils in which they will produce peaches,” said Ali Sarkhosh. “The rootstocks identified from his research will improve the sustainability of peach production in Florida.”

Lesmes-Vesga’s research matches the correct root system with soils that vary in the Indian River region and Florida’s central or “Ridge” area near Lake Alfred. Both regions have a traditional citrus production heritage. Peaches are an alternative crop for citrus growers who struggle with a worldwide disease called citrus greening and want to diversify their operations.

“Ricardo’s research will permit us to develop new, improved rootstocks designed to increase water and fertilizer use efficiency,” said José X. Chaparro, UF/IFAS Horticultural Sciences Department associate professor of fruit tree breeding and genetics. “The germplasm used in this research will be made available to nurseries for the propagation of low-chill peach varieties.” Germplasm is genetic material like seeds and plant tissue used to breed and preserve specific phenotypes or characteristics of a peach tree and its fruits, such as white flesh and juicy, sweet flavor in Florida peaches. Chaparro, one of Lesmes-Vesga’s graduate advisors, is the only Florida peach tree breeder. Chaparro said ‘low-chill’ peach varieties do not require long periods of low temperatures to bloom and produce fruit, as do peaches from traditional growing regions.

“Historically, commercial propagation of peach rootstocks has been based on the use of seedlings because they are inexpensive and easy to store,” said Lesmes-Vesga. “However, the trend in stone fruit production is the propagation of rootstocks by rooted stem cuttings, which can provide highly uniform tree performance.”

At the UF/IFAS-IRREC, Lesmes-Vesga operates a greenhouse nursery for peach trees he uses in his yearlong experiments. During the cooler months, red lights simulate daylight to prevent dormancy in the stone fruit trees. Cuttings from the nursery trees are rooted inside aeroponics systems and stimulated with rooting hormones. Collected data will reveal which rootstocks grow deeper and shallower root systems.

At IRREC, UF/IFAS Horticultural Sciences Department Lorenzo Rossi, an assistant professor of plant root biology, oversees Lesmes-Vesga’s work. “Ricardo is redesigning root system architecture, so we will have rootstocks more suitable for soils along the Indian River that often flood, and soils in the central Ridge area where roots extend deep into the soil,” said Rossi.

With Lesmes-Vesga’s findings, Chaparro will carry out his plant breeding work with the best-known plant materials and roots for Florida’s peach growers. The new trees Chaparro will breed are expected to increase Florida’s peach production range, improve the commercial trees’ performance, and bring greater profits to Florida growers.

To view a video of Lesmes-Vesga in the greenhouse and in the laboratory:

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