By Taylor Livingston and Tripti Vashisth Fighting HLB alongside weather disasters like freezes and hurricanes is leaving growers with little options for sustaining yields. The Hamlin sweet orange variety is known for higher susceptibility to HLB symptoms which cause rapid tree decline, including increased pre-harvest fruit drop and canopy loss. Production strategies that target fruit drop and canopy health improvement …
Gibberellic Acid Shows Promising Results on Hamlin
By Tripti Vashisth and Taylor Livingston Grower-led trials in 2022 showed positive results of gibberellic acid (GA) treatment on Hamlin trees in Florida. This article primarily discusses two growers’ trials in detail. Both sites showed improvement in fruit production from the GA application. Many growers have adopted GA applications in the past year as part of their grove management strategy. …
Examining Hamlin Survivor Trees
By Gary England, Fred Gmitter and Manjul Dutt In 2014, most groves in Central Florida had citrus greening infection rates approaching 100%, but a Lake County grower reported that some trees in his Hamlin on Swingle blocks seemed to be relatively healthy. Some visual HLB symptoms were observed on these “surviving” trees, but they did not have the massive fall …
Gibberellic Acid Application on Hamlin Appears Promising
By Tripti Vashisth In a multi-year field trial, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers have seen beneficial effects of gibberellic acid (GA) on Valencia sweet oranges. Monthly application of GA (September to January) on Valencia improved yield on average by 30%, reduced fruit drop and elicited enhanced plant defense response. These benefits are possibly due …
Parson Brown Outperforming Hamlin
Manjul Dutt recently discussed his research on the Parson Brown (PB) sweet orange, which shows some characteristics that could make it more attractive than Hamlin, Florida’s leading early-season orange. Dutt is a University of Florida Institute of Food and Agricultural Sciences horticultural sciences researcher at the Citrus Research and Education Center in Lake Alfred. Dutt’s research, funded by the Citrus …
Trials to Seek Hamlin Alternative
Twenty-four citrus scions were approved by the Citrus Research and Development Foundation (CRDF) on March 23 for eventual use in multiple field trials around Florida. The purpose of the trials will be to find an early-season orange that is more tolerant of HLB disease than Hamlin, said CRDF Chief Operating Officer Rick Dantzler. Hamlin has long been the primary early-season …
Rootstock Effects on Valencia and Hamlin in Large-Scale Commercial Plantings
By Ute Albrecht, Sudip Kunwar and Jude Grosser Prior to 1865, the only rootstocks used in Florida were sour orange and sweet orange. Use of grafted trees instead of seedling trees became necessary because of the devastating effects of phytophthora on sweet orange. Sour orange was widely used as a rootstock because of its resistance to phytophthora and other positive …
Varieties: Replacing Hamlins with Early Valencias
University of Florida/Institute of Food and Agricultural Sciences plant breeder Jude Grosser makes a case for Florida’s citrus industry replacing Hamlin oranges with early-maturing Valencia oranges that he and others are developing. “I think that’s a no-brainer because Hamlins are having a really bad time with greening, and orange juice sales are declining,” Grosser says. “Hamlin is half our juice. …
Reduce Fruit Drop From Phytophthora-Induced Brown Rot
By Chris Oswalt During this time of the year, Florida growers should be aware of the potential for the development of citrus brown rot disease. It can infect fruit at color break. If severe, the disease can cause a significant amount of infected fruit to drop. For this reason, groves with a history of brown rot in areas that recently …
Argentine Orange and Tangerine Forecasts Slashed
The U.S. Department of Agriculture Foreign Agricultural Service (USDA FAS) has reduced its 2023–24 production forecasts for Argentine oranges and tangerines by 44% and 30%, respectively, since the last forecasts. The 2023–24 crops are now expected to be 650,000 metric tons (MT) of oranges and 280,000 MT of tangerines. The decrease in production is due to a combination of factors, …
Trunk Injection Shows Positive Results on Early Varieties
Sponsored Content Q: There have been questions about the effectiveness of ReMedium TI® injections on early varieties like Hamlins. What have you seen from the data collected this past season? Tom Johnson: The early varieties respond well to ReMedium TI® injection. We received data from a grower that had three separate blocks of Hamlins. Each block was about 70 acres. …
Where Do Growers Stand With Trunk-Injection Therapy?
Florida growers are well into their second application of oxytetracycline (OTC) trunk injection as the 2023–24 season winds down. The results of the first application made last year are becoming somewhat clearer, but there’s still more to observe and learn about trunk injection. Ute Albrecht, associate professor of plant physiology with the University of Florida Institute of Food and Agricultural …
Brazil’s First Forecast for the 2024–25 Citrus Season
The 2024–25 orange crop forecast for Brazil’s São Paulo and West-Southwest Minas Gerais citrus belt, published on May 10 by Fundecitrus and its cooperators, is 232.38 million 90-pound boxes. The projected volume represents a significant drop of 24.36% as compared to the previous crop of 307.22 million boxes. VARIETY BREAKDOWN Production by variety is divided as follows (figures in parentheses …
Trunk-Injection Suggestions
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professors Ute Albrecht, Ozgur Batuman and Megan Dewdney recently wrote Suggested Use Pattern of Injectable Antimicrobials for Huanglongbing (HLB) Management (April 2024). They emphasized that the document is not an official UF/IFAS recommendation but is based on the labels for antimicrobial products ReMedium and Rectify. Some key suggestions in …
Grower Panel: OTC a Net Positive So Far
Florida Citrus Mutual recently hosted a roundtable discussion about the performance of trunk-injection therapies as growers are making their second round of applications. The grower participants included Jim Snively, Southern Gardens Citrus; Glenn Beck, Beck Bros. Citrus and Wes Soria, Sorrells Citrus. University of Florida scientist Ute Albrecht also joined the panel to provide a research update. Rick Dantzler, chief …
Final Orange Forecast for Brazil’s 2023–24 Season
Fundecitrus and its cooperators published the final orange production forecast on April 10 for the 2023–24 crop season in Brazil’s São Paulo and West-Southwest Minas Gerais citrus belt. The forecast calls for 307.22 million 90-pound boxes of oranges, unchanged from the February forecast. The final forecast by variety is: The season’s production was 2.2% lower than the prior year’s crop …
CRAFT Program Promotes New Planting and Knowledge
Since its founding in 2019, the Citrus Research and Field Trial (CRAFT) program has been responsible for the planting of just under 10,000 acres of new trees. This includes about 6,000 acres of solid-set groves and just shy of 4,000 acres of resets. CRAFT is a first-of-its-kind program and considered an innovation among funding agencies needed to support such efforts. …
Surviving to Fight Another Day
Bill Lennon is working with researchers to learn more about survivor trees that are standing up to HLB. Bill Lennon is a fifth-generation citrus grower who can recall the industry’s glory days when Central Florida had hundreds of thousands of citrus acres before the 1980s freezes pushed production southward in the state. But he’s remained dedicated to the area, managing …
CRISPR Is Bringing Citrus Closer to HLB Resistance
You’ve probably heard the term CRISPR in recent years. It is a relatively new breakthrough in science that has applications in human health and even in the fight against HLB. Nian Wang, a professor of microbiology and cell science with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), has been on the forefront of CRISPR research. Here …
CITRUS NURSERY SOURCE: A Day of Learning About New Rootstocks and Varieties
By Peter Chaires The U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) U.S. Horticultural Research Laboratory and Florida Citrus Research Foundation (FCRF) jointly held an open house, variety display and field tour at the W.H. Whitmore Foundation Farm between Leesburg and Groveland in early December. This annual event provides a great opportunity for industry members to see the latest innovations in …