Trunk Injection Wounding: What You Need to Know

Josh McGillHLB Management, Tip of the Week

By Ute Albrecht and Leigh Archer  Trunk injection is an alternative technique for applying crop protection materials. This technology has now been approved to deliver oxytetracycline (OTC) for huanglongbing (HLB) management in Florida. Injections cause injury, and best practices need to be established to minimize injection-induced tree damage. University of Florida Institute of Food and Agricultural Sciences researchers (UF/IFAS) injected …

Optimize Zinc and Potassium Applications to Prevent Fruit Drop

Josh McGillFruit Drop, Nutrition, Tip of the Week

By Fernando Alferez, Daniel Boakye, Murillo De Sousa and Pablo Orozco After HLB was first detected in Florida, increase in disease-associated preharvest fruit drop in affected trees has significantly reduced grower returns. Fruit drop is normal in healthy citrus, accounting for 10% to 15% of the total crop. However, under endemic HLB conditions and depending on the variety, crop loss …

Breeder Advice on Nutrition, Scions and Rootstocks

Josh McGillNutrition, Rootstocks, Varieties

Citrus breeder Jude Grosser recently shared tips on tree nutrition and discussed some scion/rootstock combinations that should work well for trees producing juice oranges. NUTRITIONGrosser became very interested in citrus nutrition several years ago in an effort to keep his newly bred trees healthy in the face of HLB. The University of Florida Institute of Food and Agricultural Sciences professor …

Combine Plant Growth Regulators for Most Benefit

Josh McGillCitrus Expo, PGRs

Using the plant growth regulators (PGRs) gibberellic acid (GA), 2,4-D and cytokinin in combination can maximize the benefit for HLB-affected trees, researcher Tripti Vashisth reported recently. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor of citrus horticulture and production works at the Citrus Research and Education Center in Lake Alfred. She discussed the benefits of …

Treat HLB Trees With the Right PGR at the Right Time

Josh McGillHLB Management, PGRs, Research

By Tripti Vashisth, Wesley Webb and Taylor Livingston As trees become symptomatic for HLB, leaves experience an imbalance of plant hormones. This hormonal imbalance exacerbates HLB symptoms and can lead to more stem dieback, poor vegetative growth and fruit drop. This ultimately leads to reduced bearing wood, resulting in yield losses and tree decline. Thus, the use of growth-promoting hormones …

Trunk Injection: Rootstock vs. Scion

Josh McGillHLB Management, Tip of the Week

By Ute Albrecht, Larissa Nunes and Gabriel Pugina   The current label recommends trunk injection of oxytetracycline (OTC) into the rootstock, but this may not always be possible. Previous University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) studies have shown that both rootstock and scion injections are effective. However, researchers have not yet studied if different rootstocks influence …

HLB Tools for Today and Tomorrow

Josh McGillCitrus Expo, HLB Management

By Frank Giles and Tacy Callies The Citrus & Specialty Crop Expo hosted two citrus educational sessions during the Aug. 16–17 event held at the Florida State Fairgrounds in Tampa. The sessions included both long-term research aimed at delivering trees resistant to HLB as well as what growers can do today to help mitigate the effects of the disease in …

Brazilian

Season’s First Update to Brazil’s Orange Forecast

Josh McGillBrazil, Crop Forecast

The first update of the 2023–24 orange crop forecast for the São Paulo and West-Southwest Minas Gerais citrus belt confirmed the initial May forecast of 309.34 million boxes. Fundecitrus announced the update on Sept. 11. The forecast for Hamlin, Westin and Rubi varieties was increased 3.5% to 58.09 million boxes. Other early-season varieties climbed 1.6% to 18.51 million boxes. The …

Citrus Harvesting Trends in Florida

Josh McGillEconomics, Labor

By Ariel Singerman Harvesting citrus is manual and labor intensive, making the cost of labor a key component of the cost of harvesting. The H-2A guest worker program allows companies to temporarily hire non-U.S. citizens to perform agricultural labor or services of seasonal nature. Given that domestic workers for harvesting are in short supply, harvesting companies in Florida (and other …

The Benefits of Growing Citrus on UV-Metalized Reflective Mulch

Josh McGillHLB Management, Research

By Jawwad Qureshi, Lauren Diepenbrock and Davie Kadyampakeni Protecting citrus trees from the Asian citrus psyllid (ACP) is critical to reducing the spread and severity of huanglongbing (HLB) or citrus greening disease. ACP, the vector of the pathogen responsible for causing HLB in citrus, needs young shoots to develop and reproduce. The frequent availability of viable shoots in young trees …

Alico Citrus Production Halved

Josh McGillfinancial, hurricane

Florida citrus grower and landholder Alico, Inc. on Aug. 3 announced financial results for the third quarter of fiscal year 2023 and the nine months ended June 30, 2023. For the nine months, Alico harvested approximately 2.7 million boxes of citrus, a decrease of approximately 51% from the same period in the prior fiscal year. After the completion of the …

Biologically-Based Management of Citrus Pests

Josh McGillBiologicals, Pests, Tip of the Week

By Jawwad Qureshi Management of the Asian citrus psyllid (ACP, Figure 1) is critical because it is responsible for spreading huanglongbing (HLB) disease. Although HLB is established in Florida, it continues to spread through ACP feeding in already infected trees and by infecting newly planted young trees. Some ACP control occurs naturally in the environment by beneficial organisms such as …

Nutrition and Irrigation Role Reinforced for HLB Trees

Josh McGillIrrigation, Nutrition

In a virtual seminar for growers on July 19, Davie Kadyampakeni reinforced that optimal, balanced nutrition and frequent irrigation can improve HLB-affected citrus trees, yield and fruit. Kadyampakeni is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor at the Citrus Research and Education Center in Lake Alfred. NUTRITION“Citrus fruit yields, juice quality and canopy size …

South Africa Orange Production Steady

Josh McGillCrop Forecast, International

Fresh orange production in South Africa is forecast at 1.63 million metric tons (MMT) in 2022–23, compared to 1.61 MMT in 2021–22, the U.S. Department of Agriculture Foreign Agricultural Service (USDA FAS) reported. The Western Cape province was affected by damage from hailstorms and strong winds, which may hamper production. Additionally, the Eastern Cape province received heavy rains, which could …

citrus

Final U.S. Citrus Forecast Has Several Changes

Tacy CalliesCrop Forecast

The final U.S. Department of Agriculture National Agricultural Statistics Service (USDA NASS) citrus forecast for the 2022–23 season, issued July 12, has several changes from the June forecast. FLORIDAFlorida’s all-orange forecast rose approximately 1% to 15.85 million boxes, up 100,000 boxes from June. The full increase is in the Valencia orange forecast, which rose to 9.7 million boxes. Florida’s all-grapefruit …

Citrus Breeding Efforts to Solve the Brix Crisis

Josh McGillRootstocks, Varieties

By Jude Grosser, Maria Brenelli, Ling Liu, Yu Wang and Fred Gmitter The combination of HLB and hurricane Ian have made this a disastrous year for Florida citrus, drastically reducing the quantity and quality of processing oranges. Brix values are the lowest in history. Early-season Hamlin juice with inferior quality is generally blended with late-season Valencia to achieve the target …

European Orange Production to Decline

Josh McGillCrop Forecast, International

European Union (EU) orange production is projected at nearly 5.8 million metric tons (MMT) for 2022–23, almost a 13% reduction from the previous season, according to a U.S. Department of Agriculture Foreign Agricultural Service (USDA FAS) report. Reductions are expected mainly in Spain and slightly in Italy and Portugal. SPAINOrange production in Spain is projected to decline by 22.8%, amounting …

USDA Citrus Breeding Program Focused on Rootstock and Variety Solutions

Josh McGillBreeding, Rootstocks, Varieties

The U.S. Department of Agriculture’s (USDA) U.S. Horticultural Research Laboratory in Fort Pierce, Florida, has been home to a citrus rootstock and variety breeding program for many years. Kim Bowman, a research geneticist, has been with the program for more than 30 years. More recently, Matthew Mattia, a geneticist, joined the breeding team. They provide an update on the program …

Economists Study Cover Crops in Citrus

Josh McGillCover Crops, Research

Economists with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) recently published two studies about the adoption of cover crops in citrus. One looked at the economic feasibility of cover crop adoption for citrus growers. The other looked at the preferences and willingness of growers to incorporate cover crops into their production practices. The studies were conducted …

Eliminate Fire Ants to Improve ACP Control

Josh McGillBiologicals, Pests

By Lukasz Stelinski Ants can be involved in mutualistic relationships with honeydew-producing hemipterans. Ants provide protection against their natural enemies, and in return, hemipterans reward ants with honeydew. Such mutualism may affect population regulation of hemipterans by third trophic level predators. However, current knowledge regarding the effects of this food-for-protection mutualism of ants with Asian citrus psyllid (ACP, Diaphorina citri) …