By Rhuanito S. Ferrarezi, Waqar Shafqat, Hernan Soto, Mark Ritenour, Lorenzo Rossi,Davie Kadyampakeni, Evan Johnson and Kelly Morgan Florida citrus growers have been using high-density planting and different soil and foliar fertilizer application strategies to compensate for the adverse effects of huanglongbing (HLB). Recent studies indicate that high-density plantings and enhanced nutritional programs with higher micronutrient levels, such as the …
What CRAFT Wants for Cycle III
Five Citrus Research and Field Trial (CRAFT) Technical Working Group leaders on Aug. 31 discussed the types of projects they’d like to see CRAFT Cycle III growers pursue. The types of projects the leaders expressed interest in will, to some extent, fill gaps in knowledge expected to be gained from previous cycles. CRAFT pays Florida growers to plant trees on …
Technologies for Improved Nutrient Analysis
By Yiannis Ampatzidis and Ute Albrecht Nutrient management is important for citrus production. Regular nutrient assessments should be conducted to optimize nutrient balance and prevent deficiencies or over-fertilization. Optimizing nutrition is important for tree health and can improve tolerance to stresses and diseases. Good nutrient management requires regular field monitoring to identify problems and examine crop responses. Leaves need to …
Navel Oranges: Current Status and Future in Florida
By Pete Spyke and Bill Castle Navel oranges are fairly tolerant of HLB, are popular and easy to sell, and offer a stable source of income that is only marginally related to worldwide supply and demand. Nevertheless, the Florida navel orange industry has experienced some tough times recently. Growers are questioning whether it is possible to grow navel oranges profitably …
Grower: Young Trees Look ‘Outstanding’
In the face of production declines, pest issues and other challenges, multi-county Florida citrus grower David Wheeler of Wheeler Farms found something positive to report. “One bright spot is the health of our young trees,” he said. “They look outstanding and have been on a good program with a rotation of insecticides.” Wheeler Farms’ more mature citrus trees aren’t doing …
Valencia Grove Design Research Earns Award
Scientists who showed that high-density plantings yield considerably more Valencia oranges, among other findings, have been honored by the American Society for Horticultural Science. Researchers Rhuanito “Johnny” Ferrarezi, Mark Ritenour and Alan Wright won the society’s Outstanding Fruit Publication Award. The University of Florida Institute of Food and Agricultural Sciences researchers work at the Indian River Research and Education Center …
Before You Spray
By Matt Smith Editor’s note: This article grants one continuing education unit (CEU) in the Core category toward the renewal of a Florida Department of Agriculture and Consumer Services restricted-use pesticide license when the accompanying test is submitted and approved. We often think about pesticide safety and best management practices when we are in the field spraying. You’re outside, you’re …
PIECES OF THE PAST: The ‘Plymouth Rock’ of Citrus
I recently acquired a visitor’s guide for Plymouth Citrus Products Cooperative. The guide invited visitors to tour the cooperative’s facilities located in where else but Plymouth, Florida, which is between Orlando and Leesburg. According to the guide, the cooperative provided “quality canned and frozen citrus products, citrus pulp and molasses.” Visitors were encouraged to take a guided tour that showcased …
Indian River Millennium Block Shows Rootstock Effects
By Rhuanito S. Ferrarezi, J. Martin Zapien-Macias, Mac Hossain, Tom James, Ronald D. Cave, Peter Spyke, William S. Castle, Jude W. Grosser, Fred Gmitter and Ed Stover In the last decade, huanglongbing (HLB) has reduced production of Florida grapefruit by 75%, mandarin by 78% and sweet orange by 52%. This decrease is significant for the Indian River District, which produces …
Growers Benefit From Citrus Nutrition Box Program
Florida growers participating in the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) citrus nutrition box program have found great value in the program. Now in its second year of operation, the program provides free soil and leaf testing as well as tailored quarterly nutritional counseling. These free boxes of materials and instructions are distributed to registered growers …
Root Depth Isn’t What It Used To Be
By Evan Johnson, Tanyaradzwa Chinyukwi, Lorenzo Rossi and Davie Kadyampakeni Huanglongbing’s (HLB) detrimental effect on roots has changed how we think about root health and horticultural management of citrus in Florida. As part of the work studying nutritional responses described in Effect of Nutrients on Canopy Response and Yield, we are studying the effects of macronutrient and micronutrient fertilization on …
Effect of Nutrients on Canopy Response and Yield
By Davie Kadyampakeni, Tanyaradzwa Chinyukwi, Alan Wright and Rhuanito Ferrarezi The development of an efficient nutrition program for citrus trees provides the essential elements for optimum tree growth and yield. Tree performance is reduced when an essential element is deficient, while an excessive amount leads to plant toxicity and hinders overall tree performance. In citrus production, adequate fertilization rates help …
Optimizing Irrigation and Young Tree Management
By Davie Kadyampakeni and Sandra Guzmán Young citrus trees require optimal irrigation management for vigorous vegetative growth, leaf flushing and the establishment of a dense canopy. Poor practices such as infrequent irrigation or not using irrigation scheduling tools could be costly. Young tree growth also could be impacted by excessive water and nutrient losses. Crop water stress in young trees …
HLB Slowed by Biocontrol
Florida citrus growers may have a new tool to help them slow the presence of HLB in already diseased trees, courtesy of researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS). The researchers found that injecting a benign Xylella fastidiosa EB92-1 bacteria biocontrol into infected citrus trees over a period of six years reduced the incidence …
Growers Discuss Fruit Drop and More
Fruit drop, drought, fruit quality, production costs, deer and Diaprepes root weevil were among problems that bothered Peace River Valley Citrus Growers Association (PRVCGA) members in the 2020-21 season. Those were the issues raised by panelists at a PRVCGA grower roundtable luncheon on May 4 in Hardee County, Florida. “The fruit drop has been the biggest problem this year,” …
How Artificial Intelligence Can Enhance the Citrus Industry
By Yiannis Ampatzidis Artificial intelligence (AI) is a promising area in computer science, automation, robotics and agriculture. AI describes the capability of a machine to imitate intelligent human behavior and mimic cognitive functions such as learning and problem-solving. Machine learning, which is an application of AI, is based on the idea that a machine, such as a computer or microcontroller, …
Updating Guidelines for New Plantings
Researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) are taking a whole-systems approach to update current recommendations for new plantings. A research project, “Establishing Healthy Citrus Plantings in the Face of Persistent HLB Pressure,” is led by UF/IFAS entomologist Lauren Diepenbrock. According to Diepenbrock, current guidelines were created pre-HLB and therefore are out of date …
Grower Instigates Sap Analysis Research
Indian River area citrus grower Cody Estes provided the impetus for an upcoming research project into the use of sap analysis for monitoring citrus tree nutrient levels. The analysis method has been used in other crops. Advocates declare it to be a relatively inexpensive way to quickly determine nutrient status so growers can make corrections before nutrient excess or deficiency …
Herbicide Adjuvants in Citrus Weed Control
By Ramdas Kanissery Adjuvants (derived from Latin, adiuvare: to aid or help) are materials added into an herbicide spray solution that improve handling, performance and crop safety. To be effective, an herbicide must overcome certain environmental and biological obstacles before entering and acting in the weeds. For example, environmental conditions like hot and dry weather will result in a thicker …
Making Sense of Biologicals: Crop Optimization With Seaweed
Sometimes growers must think outside the box to remain sustainable amid high input costs and devastating diseases. That is the situation facing citrus growers who are struggling to remain viable in the era of citrus greening. What if seaweed could be used to aid in the quality of citrus production? Seaweed is a biostimulant that is part of the biological …





























