By Davie Kadyampakeni, Kondwani Kamsikiri and Alisheikh Atta Water scarcity is one of the major constraints in Florida citrus production systems, primarily due to erratic rainfall patterns and the low water- and nutrient-holding capacity of the predominantly sandy soils. The state’s soils contain more than 95% sand and have low organic matter (<1%) and very low water-holding capacity. These challenges …
HLB-Tolerant Varieties Available
Florida Foundation Seed Producers, Inc. (FFSP) has signed a licensing agreement with New Varieties Development and Management Corp. (NVDMC) to introduce new citrus varieties showing tolerance to HLB. The HLB-tolerant varieties covered by the agreement are: The collaboration also includes the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) and the Florida Department of Citrus. It aims to …
Brassinosteroids Improve HLB-Affected Tree Health and Fruit Quality
By Fernando Alferez, Divya Aryal and Saoussen Ben Abdallah In the last few years, the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) citrus horticulture team at the Southwest Florida Research and Education Center (SWFREC) in Immokalee has performed several research trials in commercial farms and at the experimental farm at the SWFREC to elucidate the effect of …
HLB Quarantine Expands in California
The California Department of Food and Agriculture (CDFA) declared a citrus quarantine expansion in San Diego County’s Valley Center on March 26. The expansion occurred after detection of HLB disease in two citrus trees in residential neighborhoods in the Valley Center area during regular inspections. HLB is a major threat to San Diego County’s $144 million annual citrus crop …
Combine Proven Horticultural Practices to Combat HLB
By Tripti Vashisth and Prudhvi Vulchi To mitigate the effects of huanglongbing (HLB) on tree health and productivity, growers are encouraged to adopt proven horticultural practices. Based on recent field trials at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center (CREC), one effective approach combines frequent irrigation (FI), plant growth regulators (PGRs) …
Separating HLB-Affected and Healthy Fruit
Scientists with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) and the U.S. Department of Agriculture Agricultural Research Service (USDA/ARS) recently wrote about efforts to identify HLB-affected versus healthy citrus fruit. UF/IFAS scientists are Mark Ritenour, Ketan Shende and Thomas Burks. Michelle Heck is with the USDA/ARS. A slightly edited version of their article follows: Most citrus …
HLB Quarantine Area Expanded in California Again
Federal and state officials have expanded the quarantine for huanglongbing (HLB, also known as citrus greening disease) in the Mission Viejo area of California’s Orange County. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS), in cooperation with the California Department of Food and Agriculture, expanded the quarantine by 13.16 square miles. The expansion was in response …
Recovering Unprotected HLB-Infected Young Trees
By Fernando Alferez and Saoussen Ben Abdallah Individual protective covers (IPCs) are now being increasingly adopted in Florida to protect newly planted citrus trees from psyllid colonization. The risk of new citrus plantings becoming infected with HLB is especially high, as young trees flush more frequently and attract more psyllids. However, the adoption of IPCs does not occur in all …
Hope for an HLB-Resistant Tree
Rick Dantzler, Citrus Research and Development Foundation (CRDF) chief operating officer, believes there is a future for Florida’s citrus industry. His optimistic outlook is based on approaches that researchers have implemented to help growers survive in the short term, such as oxytetracycline (OTC) trunk injection, and work toward the development of an HLB-resistant tree. Dantzler shared that hope during the …
Not If Georgia Will Get HLB, But When
Citrus greening disease, also known as huanglongbing (HLB), is not yet widespread in Georgia. However, there’s no reason to think that it won’t become more of a problem for the state’s citrus growers. Lindy Savelle, executive director of the Georgia Citrus Association (GCA), hopes it doesn’t happen but cautions growers about the disease’s potential beyond Florida. “Something we have to …
Mathematical Modeling Is Preparing Europe for HLB
A tool predicting how to protect European citrus from HLB shows how mathematical modeling can help prepare for future plant disease invasions. Europe is currently unaffected by HLB. However, there are increased concerns of an infestation since psyllids that spread HLB have been found in key citrus-producing countries, including Portugal and Spain. In response to the HLB threat, a new …
Emergency Program Expanded in California for HLB/ACP
The California Department of Food and Agriculture (CDFA) recently announced the expansion in Orange County of an emergency program for HLB and the Asian citrus psyllid (ACP) that spreads the disease. The expansion follows confirmation throughout January of the causative bacterial agent of HLB in plant tissue and/or ACP in Anaheim, Costa Mesa, Garden Grove, Irvine, Mission Viejo, Orange, Santa …
HLB Confirmed in Arizona for First Time
HLB was recently confirmed for the first time in Arizona, first in an Asian citrus psyllid (ACP) and then in another ACP and citrus plant tissue. The Arizona Department of Agriculture (AZDA) reported the details. On Dec. 16, 2024, agriculture inspectors collected ACP and plant tissue samples from a residential citrus tree in Nogales. The collections were made during a …
Quarantine Updates: HLB in Mississippi; Mexfly in Texas
The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA/APHIS) recently announced a quarantine for huanglongbing (HLB) in Mississippi as well as updates to Mexican fruit fly (Mexfly) quarantines in Texas. HLB APHIS, in cooperation with the Mississippi Department of Agriculture and Commerce, established a quarantine for the entire state of Mississippi for HLB. The action was taken …
Frequent Irrigation Is Critical for HLB-Affected Trees
By Tripti Vashisth and Mary Sutton HLB-affected trees have small and weak root systems. These trees often experience water and nutrient deficit. However, not all HLB-affected trees experience the same impact. Trees with severe HLB symptoms will have higher root loss and water deficit than trees with mild HLB symptoms. The water deficit exacerbates during spring, which is often the …
Rejuvenate HLB Trees With Precision Nutrient Management
By Meryam Manzoor, Jamie D. Burrow, Taylor Livingston and Tripti Vashisth Effective nutrient management and accurate nutritional analysis are critical for tree growth and maximum yield. Historically, nutrient management for healthy citrus trees involved annual leaf sampling from July to August, with subsequent fertilization plans based on a single nutrient analysis. Almost all commercial citrus groves in Florida are affected …
Florida Citrus Commission Actions and HLB
Florida Citrus Commission (FCC) Chairman Steve Johnson recently discussed HLB and several actions and reports from the commission’s December 2024 meeting. The FCC is the governing board of the Florida Department of Citrus. “For almost two decades, we’ve been in a season of fighting HLB, and that fight (while the war is far from over) is changing,” Johnson said. “The tools …
Top Priorities: HLB Resistance and Hurricane Recovery
With 2024 in the rear view mirror, we asked leaders of key citrus organizations what their priorities are for this year. Here’s what they had to say. TREE OF THE FUTURE “For the last 2.5 years, our research strategy at the Citrus Research and Development Foundation has been to kill the bacteria that causes HLB — Candidatus Liberibacter asiaticus (CLas) …
Weathering the HLB Storm
Specialty crop growers might be aware of the disease sweeping through Florida’s citrus industry. Its impact has been tremendous and has tested the survival of the state’s signature crop. This year will mark the 20th anniversary of the official confirmation of citrus greening disease (also known as huanglongbing or HLB) in Florida. In the past two decades, the state’s output …
Study Shows Impact of HLB Bacterium on Roots
A recent study sheds light on the significant effects of Candidatus Liberibacter asiaticus (CLas), the bacterium responsible for HLB, on the root systems of grafted Valencia orange trees. The findings reveal that root system reductions caused by the infection are more extensive than the corresponding aboveground declines. That finding underscores the hidden yet critical impact of the disease below the …