By Laura Reuss, Fred Gmitter and Yu Wang Sweet orange and mandarin fruits are the most popular citrus crops worldwide. Although often mistakenly considered one and the same, oranges and mandarins are different species with specific distinctions. For instance, mandarins are smaller and easier to peel than oranges. Additionally, mandarins are primarily eaten as fresh fruit, whereas most sweet oranges …
Fruit Drop and HLB
By Tripti Vashisth and Lisa Tang Fruit drop is a natural, physiological phenomenon that occurs in all citrus varieties. However, pre-harvest fruit drop often causes grower distress and concern as it can result in significant yield reduction as well as loss of tree resources into non-harvested fruit. THREE PERIODS OF FRUIT DROP In general, citrus trees bloom profusely in spring, …
Individual Tree Covers for HLB Defense
University of Florida Institute of Food and Agricultural Sciences researcher Jim Graham shares preliminary results from a new trial aimed at protecting trees from HLB infection at the Southwest Florida Research and Education Center. During the first five months of the trial, individual protective covers (IPCs) successfully kept psyllids off young trees and delayed HLB infection. Trees under the covers …
HLB-Detector Dogs Coming to California
The use of canines or “sniffer dogs” is again being investigated by the U.S. Department of Agriculture (USDA) for early detection of HLB-infected trees. Through the HLB Multi-Agency Coordination (MAC) program, USDA Animal and Plant Health Inspection Service (APHIS) has invested millions of dollars in the research and training of detector canines for finding HLB-positive trees. A recent full-day meeting in …
Black Discusses HLB Research Meeting
Larry Black, president of Florida’s Citrus Research and Development Foundation (CRDF), attended a recent meeting in Fort Pierce to discuss HLB research prioritization and funding. He joined officials with other agencies that fund HLB, including California’s Citrus Research Board (CRB) and the U.S. Department of Agriculture (USDA). Black says the agencies met “to look at ways we can be more …
Schulz on HLB Research Funding Session
Gary Schulz, president of the Citrus Research Board in California, discusses a recent meeting of agencies that fund HLB research. Representatives of Florida’s Citrus Research and Development Foundation and the U.S. Department of Agriculture also attended the two-day session in Fort Pierce, Florida. According to Schulz, the National Academy of Sciences within the past year recommended “that funding agencies for …
Early Findings Show Plant Hormone May Help in HLB Fight
University of Florida scientists think a group of hormones may eventually help growers battle citrus greening, but they still want to study them before recommending growers use the chemical. Fernando Alferez, an assistant professor of horticultural sciences at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), leads a team of UF/IFAS researchers studying the effects of Homobrassinolides …
HLB Alters Nutrition Needs
Yield and fruit size are not good measurements of the nutrition needs of HLB-affected trees, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers have discovered. “So we decided to go with something that’s fruit independent for the study,” says UF/IFAS scientist Arnold Schumann of the Citrus Research and Education Center at Lake Alfred. Schumann says he and …
Texas A&M AgriLife Research, Consortium Get Grant for HLB Research
A Texas A&M AgriLife Research scientist at Weslaco will lead a consortium of researchers in major citrus-producing regions to conduct high-throughput screening in discovering antimicrobials that could prevent citrus greening. Citrus greening, also known as huanglongbing (HLB) disease, has devastated citrus fruit crops in Florida and has made its way to Texas and California. The research grant of approximately $1.2 …
New CRDF Leader Discusses HLB Battle
Moments after being chosen on July 24 as the next chief operations officer of the Citrus Research and Development Foundation (CRDF), Rick Dantzler declared the industry will “whip” HLB. He chose Aug. 15 as his first day of work so he can meet many growers at Citrus Expo. “I wanted my first day on the job to be with citrus …
Update on Premier’s HLB Efforts
Harold Browning with Premier Citrus ApZ updates his company’s efforts to make bactericides more effective against HLB. He says Premier is “trying to move to commercialization as quickly as possible a technology to improve the absorption of materials that would kill HLB bacteria in infected trees.” “One of the challenges we face in trying to get materials into the phloem …
The Economics of Planting Density in the HLB Era
University of Florida Institute of Food and Agricultural Sciences researcher Ariel Singerman led efforts to analyze the economic viability of planting at different tree densities under endemic HLB conditions. The analysis describes the establishment and production costs of a new grove for three tree planting densities under different market conditions. “Excel files containing the analysis and a companion file describing …
Tree Spacing and Technology for HLB
Jim Snively, vice president of grove operations for Southern Gardens Citrus, discusses planting density and technology that may hold promise for coping with HLB. Tree density trials were planted in 2012 at Southern Gardens. After six years, the best results have come from trees planted at about 363 trees per acre, Snively reports. “Everything we’re doing today, we try to …
How a Processor Is Coping with HLB
Everyone in the citrus business knows HLB has wreaked havoc on Florida citrus growers. But it has also caused severe problems for processors, said Bob Behr, CEO of Florida’s Natural Growers (FNG). FNG is one of the nation’s largest processors and marketers of orange juice. Behr told the audience at the recent Florida Citrus Industry Annual Conference that low citrus …
Bayer on HLB: No Single Solution Likely
Denise Manker with Bayer CropScience provides an update on Bayer’s collaborative effort with the Citrus Research and Development Foundation to seek solutions for HLB. Her presentation came during the recent Florida Citrus Industry Annual Conference in Bonita Springs. Manker told the audience there will not likely be a “silver bullet” that will provide a solution to the disease. “I think …
Field Testing of New HLB-Tolerant Scions and Rootstocks
By Rhuanito S. Ferrarezi, Jude W. Grosser, Fred G. Gmitter, Ed Stover and Kim Bowman Citrus is Florida’s most important agricultural commodity. The state produces citrus for different markets: round oranges for juice; navels, mandarins, grapefruit and lemons for the fresh-fruit industry; and lemons for extracting peel oil for processing. Huanglongbing (HLB) disease affects all citrus varieties. Since the discovery …
A Grower’s Plan to Survive HLB
An Indian River-area grapefruit grower told the crowd at Florida Citrus Mutual’s recent annual conference about his company’s plans for coping with HLB. The plans include replanting with some diverse citrus varieties at higher densities, said Daniel Scott, vice president of Scott Citrus Management. Grapefruit has for the most part proven extremely difficult to grow profitably in the face of …
Certis for Citrus Program Helps Fund Fight Against HLB
The biopesticide company, Certis USA, presented the non-profit Citrus Research and Development Foundation, Inc. (CRDF) with a check for $20,000 to help fund research projects in an effort to find a cure for huanglongbing (HLB; citrus greening). The presentation was made during the Florida Citrus Industry Annual Conference that took place at the Hyatt Regency Coconut Point Resort and Spa. …
Extra Manganese and Boron for HLB
University of Florida Institute of Food and Agricultural Sciences researcher Jude Grosser discusses small experiments that indicated manganese and boron can help citrus trees cope with HLB. In a greenhouse experiment from a few years ago, HLB-infected sweet orange trees were overdosed with micronutrients and secondary nutrients. “It looked like … manganese had the biggest effect on growth of the …
Zinkicide Could Help Manage HLB
University of Florida Institute of Food and Agricultural Sciences researcher Evan Johnson reports that the product Zinkicide appears promising as a management tool for HLB. “Zinkicide is a zinc-based nanoparticle that is designed to become systemic inside the tree and has high bactericidal activity so that hopefully it can target Liberibacter,” Johnson says. Liberibacter is the causal agent of HLB. …