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 …
Traditional and Alternative Leafminer Control Methods
By Lukasz Stelinski The citrus leafminer (CLM) remains a major pest of citrus throughout Florida. The adults are small, white/silver-colored moths about half the size of a typical mosquito (Figure 1). Adults are difficult to spot due to their small size and because they are active only in the evening (dusk) and early pre-dawn hours. CLM adults can be monitored …
Benefits of Biological Fungicides for Citrus Production
Since many of the regions where citrus trees grow have warm, humid climates, bacterial and fungal diseases can easily run rampant. Preventative methods are the best way to control diseases in citrus, because if problems occur once new leaves, shoots and fruit are developing, it is likely too late to stop the disease during that growing season. Growers can use …
Advice for Psyllid/HLB Control
Even with the virtually 100 percent level of HLB infection found in Florida citrus trees, reducing Asian citrus psyllids improves tree health and yield, entomologist Lukasz Stelinski says. Stelinski is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) professor at the Citrus Research and Education Center. Stelinski reports that trials the late UF/IFAS researcher Phil Stansly …
Viruses Might Help Control Asian Citrus Psyllids
(UF/IFAS) — University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers are working toward establishing a new biological method that may help growers control the insect that transmits the deadly greening disease into citrus trees. Greening is present in about 95 percent of the citrus trees in Florida, so by using a virus that may kill the insect, …
Innovation in Natural Insect Control for Citrus
By Chip Henry When I chose to produce citrus organically nearly five years ago, I accepted the responsibility of implementing a nature-based protocol of production for my grove. Subsequently, I searched for products that were available to address the aspects of nutrition, soil health, undesirable vegetation suppression and insect control. The process of “turning over every rock” was imperative, with …
Controlling Difficult Weeds in Citrus Groves
By Ramdas Kanissery, Camille McAvoy and Mongi Zekri Some weeds are more difficult to manage in the production system than others due to their ability to grow in an available niche. If given a chance to establish, Guinea grass and goatweed can be the two most difficult weeds to manage. This is not just because they both are prolific seed …
California Legislative Staff Updated on HLB Control Efforts
Recently, California Citrus Mutual (CCM) hosted a lunchtime briefing at the Capitol. The purpose was to update legislative staff on the status of HLB in California and the industry’s continued efforts to prevent the disease from spreading into commercial groves. The briefing included a panel discussion with CCM Director of Government Affairs Alyssa Houtby, California Citrus Pest and Disease Prevention …
Imidacloprid Alternatives for Psyllid Control
Phil Stansly, University of Florida Institute of Food and Agricultural Sciences entomologist, discusses alternatives to imidacloprid for helping to control HLB-spreading Asian citrus psyllids (ACP). “Imidacloprid of course is typical of the neonicotinoids that we’ve been using as soil applications to protect young trees,” Stansly says. “We’ve seen and the growers have seen, too, that soil applications of systemic insecticides …
California Judge Stops CDFA Pest Control Spraying
A California Superior Court judge has ordered the state’s Department of Food and Agriculture (CDFA) to temporarily stop spraying pesticides for agricultural pest control. The judge decided in favor of a lawsuit filed by 11 environmental activist groups and the city of Berkeley. Private citizens will still be able to use chemical insecticides on their property, but the order requires …
Psyllid Control Strategies
University of Florida Institute of Food and Agricultural Sciences entomologist Jawwad Qureshi discussed several means of Asian citrus psyllid control at Citrus Expo in August. He provides an overview of his presentation. Qureshi says it is best to start psyllid sprays during the winter dormant period. “Do it individually or do it in a collaborative effort, but you must do …
Pruning and Controlled-Release Fertilizer to Rehabilitate HLB Trees
By Tripti Vashisth and Troy Gainey Pruning is one of the oldest horticultural practices that changes the form and growth of a tree. The pruning process 1) adjusts tree shape and the ratio of framework to fruit-bearing shell of the canopy, 2) alters the shoot/root ratio and 3) changes the carbohydrate (food storage) status of the tree. Under Florida weather …
Controlled-Release Fertilizer Boosts Health of HLB Trees (Part 2)
By Pete Spyke, Joby Sherrod and Jude Grosser Part 1 of this article, published in the April 2017 issue of Citrus Industry magazine, provided some background information on controlled-release fertilizer (CRF) along with a discussion of practical applications in citrus production. This article, part 2, includes summaries of observations from several case studies in which CRF has been applied for …
Controlling ACP and Other Pests as Critical as Ever
By Jawwad A. Qureshi and Philip A. Stansly More than a decade has passed since 2006, when huanglongbing (HLB) or citrus greening disease was identified in Florida. By then, the disease had already spread widely and went unrecognized due to high psyllid populations and a disease incubation period of months or years between infection and symptom expression. Nevertheless, management of …
Controlling HLB with Thermotherapy: What Have We Learned So Far?
By Reza Ehsani, Megan Dewdney and Evan Johnson In the last two years, many growers looked at thermotherapy as a way of keeping HLB-affected citrus trees in production until a more permanent solution could be developed. It has been shown that thermotherapy can kill HLB-causing bacteria under controlled environments. But the exact time and temperature is not known, and it …
Costa Rican Orange Production
The U.S. Department of Agriculture Foreign Agricultural Service (USDA FAS) expects Costa Rican orange production to increase approximately 11% in 2024–25, to 250,000 metric tons. Production in 2023–24 was lower than expected at 225,000 metric tons as a result of erratic rainfall patterns associated with the El Niño weather phenomenon. The area planted in oranges is expected to remain unchanged …
Citrus-Derived Endophytes Have HLB Management Potential
Florida-based scientists published an article in Microorganisms indicating citrus-derived endophytes have potential for managing HLB. Endophytes are endosymbionts, often bacteria or fungi, which live within a plant for at least part of its life cycle without causing apparent disease. The authors of the article are Jessica Dominguez, Krishnaswamy Jayachandran and Kateel G. Shetty of Florida International University, and U.S. Department …
Transforming Organic Citrus Production
Organic citrus growing presents unique hurdles in Florida, Texas and other southern states. Poor soil quality, nutrient deficiencies and a limited range of pest control options plague organic production. But the University of Florida Institute of Food and Agricultural Sciences’ (UF/IFAS) Davie Kadyampakeni is poised to transform the future of organic citrus growing. He aims to do that with a …
Management of the Invasive Peanut Snail in Citrus
Two University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers and an Extension agent authored an article in the Cold Hardy Citrus Connection about the invasive peanut snail in citrus. The authors are Xavier Martini, associate professor of entomology; Issac Esquivel, assistant professor of entomology; and Extension agent Danielle Williams. Excerpts follow. Bulimulus bonariensis (also known as Bulimulus …
Parasites Fight Citrus Gall Wasps
Jianhua Mo, a research entomologist with Australia’s New South Wales Department of Primary Industries (NSW DPI) authored an article about the release of parasitic wasps for the control of citrus gall wasps (CGW). Edited excerpts follow: CGW is a pest of major concern in the southern citrus-growing regions of the Riverina, Sunraysia and Riverland. With the exception of the adult …