CITRUS NURSERY SOURCE: NVDMC Research Focus for 2026–27

By Peter Chaires

Spring is planning season for most Florida citrus organizations. New Varieties Development & Management Corp. (NVDMC) is no exception. The board recently met with all breeding teams to review 2025–26 sponsored projects and establish research priorities for 2026–27. Though some aspects of these projects will be covered in greater depth in future articles, this month’s column is an opportunity to highlight the NVDMC-approved and recommended areas of focus. Let’s take a look at project priorities for 2026–27:

UF/IFAS CREC

The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center Plant Improvement Team (Fred Gmitter, Jude Grosser, John Chater and Nian Wang) has identified the following research priorities:

• Continue to evaluate oxytetracycline (OTC) impact on advanced selections and released varieties in their third and fourth years of treatment. Injection is standard practice for most growers. This data will be of practical value.
• Collect performance data of advanced selections, primarily sweet orange.
• Place greater emphasis on data collection of material in citrus under protective screen (CUPS) and include more selections. Evaluation of more material benefits CUPs growers and provides important performance data in an HLB-free environment, so truly superior cultivars can be used for future transformation or editing.
• Plant more than 100 previously identified selections submitted over the years to the Division of Plant Industry (DPI) Parent Tree Program, in and outside CUPs, to compare HLB tolerance and performance.
• Conduct new field trials of RBA 13-18 and C4-10-42, two recently released mandarin hybrids for the juice stream.

Core breeding activities will include:

• Evaluation of leading candidates propagated from a large, abandoned research plot in Balm
• Continued efforts to introgress HLB resistance from khasi papeda into hybrid populations
• Production of new crosses
• Planting and evaluating new material
• Hosting display day and field days
• Maintaining repository collection

The goal is to find the highest-quality selections with the greatest HLB tolerance for genetic manipulation and commercialization.

Manjul Dutt’s citrus improvement team at CREC lists the following overall project objectives:

• (Short-term) Evaluate Hamlin survivor trees in Lake County grove and identify select clones for large-scale evaluation.
• (Medium-term) Evaluate enhanced HLB tolerance in an irradiated block of Carney 3 sweet oranges. Evaluate for low peel oil, seed count, quality, productivity and tolerance.
• (Medium-long term) Plant and evaluate new early maturing sweet oranges.

Dutt’s summary of this year’s results:

• Six top candidates from the block have been identified.
• Four has been certified by DPI and released for nursery propagation.
• Two have been recommended by the Citrus Research and Field Trial Foundation for the current planting cycle.
• Trees are propagated and will be planted in a replicated manner in 2026.

According to Dutt, 2026–27 focuses are:

• Complete the characterization research on the Lennon early oranges.
• Continue work with the Carney orange and early varieties (Dutt and Bill Castle introductions).
• Evaluate newly imported collection of early sweet oranges on US-942 and C-54 rootstocks.
• Re-evaluate an orange collection previously introduced by Castle. Plant trees in a replicated manner without individual protective covers to understand genetics driving performance.
• Work with growers to plant and evaluate the two Lennon sweet oranges in a replicated manner.

UF/IFAS IRREC

Mark Ritenour lists these priorities for the UF/IFAS Indian River Research and Education Center (IRREC):

• Post-harvest objectives for new fresh fruit selections are degreening, decay control, evaluation of harvesting methods, washing and waxing treatments and optimal holding temperatures.
• Post-harvest evaluations will explore external quality, internal quality, shelf life during storage and physiological disorders.
• Continue evaluating selections for the UF breeding program at CREC and at the main campus in Gainesville as they become available.
• Evaluate the effects of preharvest treatments (e.g., OTC trunk injections) when available.
• Evaluate selections from the U.S. Department of Agriculture (USDA) breeding program.
• A monthly schedule has been set up with Matt Mattia at USDA to check for selections ready for evaluation.

USDA-ARS U.S. HORTICULTURAL RESEARCH LABORATORY

Mattia shared the following objectives from the citrus breeding program at the USDA Agricultural Research Service U.S. Horticultural Research Laboratory in Fort Pierce, Florida:

• Use a fruit-forward approach to identify material with commercial potential with a focus on selecting/developing oranges, orange-like fruit, specialty fruit and grapefruit.
• Collect preliminary data to reduce grower risk of planting new selections.
• Screen varieties for juice quality.
• Identify crosses and irradiates targeted at commercial success.
• Progress with The Great American Sweet Orange Trial (planting and grove care) – Evaluate all available orange germplasm. This includes propagation of 111 true oranges, representing all the diversity available within the United States and creating mother trees for replication. The goal is to create a 10-acre (~2,200 trees) replicated trial to assess the population for HLB tolerance and ability to process.

UF/IFAS GAINESVILLE

Jose Chaparro’s UF/IFAS citrus breeding program in Gainesville will focus on breeding HLB and cold tolerance into commercially valuable citrus. The primary focus is orange-like fruit, and the secondary focus is grapefruit and specialty fruit.

Chaparro reports that a new seedless mandarin was identified that shows improved tolerance, and a new parent for breeding seedless colored grapefruit will segregate for tolerance. While the program suffered some setbacks from the freezes, much of the material was segregated for cold tolerance.

2026–27 objectives include:

• Continue data collection for release of the two most advanced selections.
• Plant replicated test of two unreleased selections plus Sederoff and Werner in Citra (US-812, US-897, UFR-1 rootstocks).
• Evaluate fruit from replicated tests of nine unreleased advanced orange-like selections on US-812 and C-54.
• Continue work of remediating a seedling plot at IRREC, paying particular attention to second-generation sweet orange-like hybrids.
• Continue the work on Eremocitrus glauca, seeking to introgress resistance into commercial quality citrus.

The NVDMC board has placed an increased emphasis on processed oranges in recent years. During the spring planning session, the board discussed recent public projections that a larger percentage of the crop is likely to be utilized in fresh channels of trade. This is becoming an economic reality for many growers. Ultimately, the board elected to keep the breeding teams apprised of current and projected trends and allow them flexibility to develop and identify candidate varieties that will meet the needs of industry, rather than dictate a specific allocation of resources.

Peter Chaires is executive director of NVDMC.