HLB and ‘Tolerance’ as a Practical Matter in Choosing Rootstocks

Tacy CalliesRootstocks

By Bill Castle (Editor’s note: Click on the graphs throughout the article to enlarge them.) By classic biological definition, a particular citrus rootstock-scion combination when infected with Candidatus Liberibacter asiaticus (CLas) would be considered tolerant if infected trees had no more than slight reductions in performance, sometimes accompanied by a reduced level of the pathogen. That definition implies that the …

Bactericide Survey Results Summary

Josh McGillBactericides, Citrus Greening

By Stephanie Slinski and Harold Browning (Editor’s note: Click on the graphs throughout the article to enlarge them.) Bactericides have been available to growers as a new tool to improve the health of HLB-infected trees since early March 2016. This use has been under a crisis declaration from the Florida commissioner of agriculture, but on August 15 of this year, …

bactericides for HLB

Snively Discusses Use of Bactericides for HLB

Ernie NeffBactericides, Citrus Expo, Citrus Greening

Jim Snively of Southern Gardens Citrus says his company is trying bactericides for HLB on one-tenth of its 10,000 citrus acres. The company is working with the Citrus Research and Development Foundation to analyze fruit drop, tree condition and more in blocks treated with bactericides. He believes it will take two to three years to determine if the bactericides are …

Putnam: Private Citrus Forecast ‘a Kick in the Gut’

Tacy CalliesForecast

Florida Commissioner of Agriculture Adam Putnam expresses pleasure at celebrating the 25th Citrus Expo and dismay at a private citrus forecast of 60.5 million boxes of Florida oranges next season. “Boy, what a kick in the gut that forecast was,” says Putnam, who is a citrus grower. He notes that post-bloom fruit drop no doubt played a role in the …

BASF Announces Label for Priaxor® Fungicide for Florida Citrus

Tacy CalliesCitrus

BASF announces that Priaxor® fungicide has received federal and Florida approval for use on all citrus varieties in Florida. Priaxor® fungicide is already being used in sugarcane and vegetables throughout the state and the United States. Priaxor® fungicide is a mixture of the active ingredient in Headline® fungicide and a new systemic fungicide Xemium®. Testing in Florida has shown the …

New Method Tells Growers More About Citrus Decay

Kelsey FryCitrus

With citrus growers trying to save their groves in the wake of the deadly greening disease, a University of Florida Institute of Food and Agricultural Sciences researcher has found a new technique that could help growers answer a vexing question – why so much fruit is dropping to the ground prematurely. If we know why fruit is dropping, we can …

bactericides survey

Sparks Discusses Citrus Tariffs and PFD

Ernie NeffLegislative, Pests

Florida Citrus Mutual CEO Mike Sparks discusses the association’s annual conference this week, including the election of a new association president, the U.S. presidential race from a tariff perspective, and postbloom fruit drop (PFD). During the conference, Mutual’s trade attorney reported on presidential candidates’ views regarding tariffs, which can impact citrus trade. Sparks comments on that report: “When you hear …

PFD

PFD, Bactericides for HLB are Top Citrus Grower Concerns

Ernie NeffCitrus, Citrus Greening, Pests

Postbloom fruit drop (PFD), along with the use of bactericides to control HLB, were the big issues for more than 40 participants in a grower roundtable Wednesday in Wauchula. LeAnna Himrod, one of the roundtable hosts, summarizes the issues addressed. Regarding bactericides, she reports: “There were a lot of questions about the bactericides regarding timing: What’s the best time of …

Florida’s

Florida’s Replanting Era: What it Means for OJ Demand

Daniel CooperFlorida Department of Citrus, Orange Juice, planting

By Marisa Zansler Over the past year, there has been a discreet change occurring in the orange juice (OJ) aisle amid supply shortages. Some of the familiar OJ cartons have changed, not in name but in composition. With Florida’s smaller crop and limited global OJ supplies, Florida’s processors have stretched that limited supply by offering more products that blend OJ …

silicon

When and How To Use Silicon for Freeze Protection and Recovery

Daniel Cooperfreeze, Nutrition, Tip of the Week

By Muhammad A. Shahid and Davie Kadyampakeni Silicon (Si) is getting a lot of attention from citrus growers as a tool to help trees handle stress, especially during cold and freeze conditions. It toughens up plant tissues, strengthens cell walls and helps trees better handle stress when it is applied at the right time. BEFORE FREEZE The most important thing …

cold-hardy

Cold-Hardy Citrus Damage Expected From Incoming Freeze

Daniel CooperCold Hardy

Trees in the cold-hardy citrus region have already experienced severe cold weather in 2026. If forecasts come to fruition this weekend, freezing temperatures will make things worse. Mary Sutton, University of Georgia (UGA) assistant professor and citrus Extension specialist, discussed the impact of recent sub-freezing temperatures that citrus in North Florida, South Georgia and South Alabama has been subjected to. …

post-freeze

Post-Freeze Citrus Management

Daniel Cooperfreeze

By Muhammad A. Shahid, KeAndre Leaks and Davie M. Kadyampakeni Right after a freeze, you may notice new growth turning black and leaves hardening, yellowing or looking water-soaked. About a week after a severe freeze, leaves may start to curl and turn brown. Leaves and fruits may begin to drop. Do not attempt any recovery treatments immediately after a freeze. …

cold-hardy

Cold-Hardy Citrus Update Following December Freeze

Daniel CooperCold Hardy, freeze

Cold-hardy citrus in the Southeast endured sub-freezing temperatures in mid-December, the second major freeze to impact the region this season. Mary Sutton, University of Georgia (UGA) assistant professor and citrus Extension specialist, discussed how this freeze impacted citrus trees and fruit in North Florida, South Georgia and South Alabama. “We’re seeing some damage on younger trees that were probably planted …

boron deficiency

Unraveling Sweet Orange Response to Boron Deficiency

Daniel CooperNutrition, Research

Chinese researchers have delved into the complex interactions between transcription processes and metabolism in sweet orange plants deficient in boron. Boron deficiency can lead to reduced yields and compromised fruit quality. Authors of the research are Xiuyao Yang, Ke Wen, Xiujia Yang, Mengjie Zhang, Ling Zhu, Yinqiang Zi, Tuo Yin, Xulin Li, Xiaozhen Liu and Hanyao Zhang, all with the …

magnesium

Fixing Magnesium Deficiency

Daniel CooperNutrition

Noting that magnesium (Mg) deficiency is a problem in Florida citrus, the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) offers the following information about its symptoms, cause and solutions. SYMPTOMS AND CAUSE Trees with inadequate Mg supply have no symptoms in the new spring flush, but leaf symptoms will develop as the leaves age and the fruit …

cold

Preparing Citrus Groves for Cold Fronts

Daniel Cooperfreeze, Tip of the Week

By Muhammad A. Shahid, Shahid Iqbal and Davie Kadyampakeni As temperatures begin to drop across citrus-growing regions, now is the time for growers to prepare their groves for potential freeze events. Citrus trees, especially young plantings, are susceptible to cold temperatures. Damage from a single freeze event can result in canopy dieback, fruit loss and even tree death. Proper planning …

temperatures

Cold-Hardy Citrus Spared From Sub-Freezing Temperatures

Daniel CooperCold Hardy, freeze

The short timeframe when temperatures dipped below freezing this week in the cold-hardy citrus region appears to have not been problematic for trees. That’s the preliminary assessment shared by Mary Sutton, University of Georgia (UGA) assistant professor and citrus Extension specialist. Sutton emphasized that the few hours that temperatures dropped into the 20s early Tuesday morning was a lot better …

potential freeze

Cold-Hardy Citrus Producers Should Prepare for Potential Freeze

Daniel CooperCold Hardy, freeze, Weather

Cold-hardy citrus producers need to be prepared for a potential freeze event next week. Mary Sutton, University of Georgia (UGA) assistant professor and citrus Extension specialist, cautioned growers on the UGA Citrus Blog that temperatures are expected to drop in the low 30s across the region next Monday and Tuesday, and perhaps in the upper 20s in some areas. The …

improve

Two Practices to Improve Citrus Production

Daniel CooperCold Hardy, Production

University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers recently explained the benefits of raised bed planting and mulching to improve citrus tree establishment, productivity and resilience against environmental stress. Assistant Professor Muhmmad Shahid and Postdoc Scholar Shahid Iqbal, both of the North Florida Research and Education Center, and Associate Professor Davie Kadyampakeni of the Citrus Research and …

export

Early-Season Export Report for Brazil

Daniel CooperBrazil, Export

The first 90 days of the 2025–26 Brazilian citrus season confirmed adjustments in the export market for orange juice (OJ) and citrus byproducts. LOWER VOLUME AND REVENUE In spite of the tariff exemption on Brazilian OJ in the United States, the performance of exports from July to September was below that verified in the same period last season. According to …