Citrus Nutrient Deficiencies? There’s an App for That

Jim Rogers Diseases, Nutrition, Pests, Technology

While sending citrus tissue samples to the lab for analysis remains important, the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has developed a smartphone application (app) that can supplement lab analysis to identify leaf symptoms of key nutrient deficiencies and certain pests and diseases. Arnold Schumann, a professor of soil and water science with UF/IFAS, demonstrated how …

Don’t Forget Citrus Black Spot in Florida

Jim Rogers Diseases

While HLB tops the agenda, Megan Dewdney, an associate professor of plant pathology and an Extension specialist with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), reminded growers that citrus black spot (CBS) remains a concern. This was the topic of a presentation she made during the Florida Citrus Growers’ Institute held in Avon Park in April. …

Greasy Green Research Approved

Jim Rogers CRDF, Diseases, Research

Due to the initiative of the Indian River Citrus League (IRCL), the Citrus Research and Development Foundation (CRDF) has approved research funding for the greasy green defect on citrus fruit. At a 2021 IRCL board meeting, the issue of greasy green spot was brought up by Tim Sallin of IMG Citrus. Other growers at that meeting also shared their experience …

How to Reduce Bingo Tree Loss to Stem Dieback

Jim Rogers Diseases, Research

By Christopher Vincent, Megan Dewdney and Liliana Cano Bingo mandarin hybrid is a variety with many promising characteristics, but it brings specific challenges to profitable production. One challenge identified early in the push to plant Bingo was stem dieback that led to tree loss. After looking into this problem for the past four years, University of Florida Institute of Food …

Comparison of ACP/HLB Management Tools for Citrus Resets

Jim Rogers Diseases, HLB Management, Research

By Lauren Diepenbrock, Megan Dewdney, Christopher Vincent and Davie Kadyampakeni As the threat of potential shutdowns loomed in March 2020, a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) team put the final plants in the ground, individual protective covers (IPCs) on trees, and kaolin and pesticide applications on a 2.7-acre planting at the Citrus Research and Education …

Fruit Size and Spraying Interval Are Key for Canker Control

Jim Rogers Diseases, Research

The size of fruit that should be sprayed, the spraying interval and ways to avoid copper phytotoxicity were among the citrus canker topics plant pathologist Megan Dewdney offered growers recently. Dewdney said fruit are most susceptible to canker when they are between 3/8 inch and 1.5 inches in diameter. The fruit rind becomes much more resistant when the fruit is …

Citrus Canker Confirmed in South Carolina

Jim Rogers Diseases

The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed the presence of citrus canker disease in a nursery in South Carolina. The nursery sells plants to consumers through online sales. Other nurseries did not receive these plants. Together with state partners, APHIS is working to collect and destroy the plants shipped to consumers in …

Black Core Rot Being Studied

Jim Rogers Diseases, International, Research

A new Hort Innovation project aims to shed some light on how black core rot happens in Australian groves so the citrus industry can learn how to better manage the disease. Black core rot caused by the fungus Alternaria spp. can be a problem for some citrus growers in the southern growing areas in Australia. Citrus infected with Alternaria spp. …

‘Irma Will Haunt Us’ Regarding Citrus Black Spot

Jim Rogers Citrus, Diseases, Weather

Citrus black spot (CBS) disease has only been found in five Southwest Florida counties, but that could change as a result of 2017’s Hurricane Irma, a researcher reiterated recently. University of Florida Institute of Food and Agricultural Sciences plant pathologist Megan Dewdney, in a Feb. 24 presentation, said “Irma will haunt us for a while.” She explained that Irma likely …

Get Canker Before It Gets You

Jim Rogers Diseases, Tip of the Week

By Megan Dewdney Spring is around the corner, and Florida’s first wave of bloom is here. But there is no time to relax and enjoy the flowers because citrus diseases wait for no grower. Young fruitlets become susceptible to canker toward the end of March to the beginning of April. Missing that key window of protection — if the weather …

Sweet Orange Scab and Citrus Canker Movement Conditions Revised

Tacy Callies Diseases, Regulation

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) has revised the conditions for interstate movement of citrus fruit from areas quarantined for both sweet orange scab (Elsinöe australis, SOS) and citrus canker (Xanthomonas axonopodis, CC). The revisions allow for the movement of fruit to packinghouses located in contiguous states that are not quarantined for either disease. …

Be Alert for Citrus Canker in Alabama

Jim Rogers Citrus, Diseases

Alabama Cooperative Extension implores growers to be on the lookout for symptoms of citrus canker disease in their trees. Commercial growers need to scout their trees regularly to stop the disease’s potential spread, says Kassie Conner, Alabama Extension specialist. “What we need people to do right now is look for these symptoms and report it if they find it,” Conner …

What to Do About Bingo Stem Dieback

Jim Rogers Diseases, Research, Tip of the Week

By Christopher Vincent, Megan Dewdney and Liliana Cano Bingo is a relatively new and unfamiliar variety, which growers initially sought as a positive alternative. However, it presents some unique production challenges. Bingo is desirable because its high-quality, low-seeded fruits are ripe in October, a valuable harvest window for Florida growers. But in the early years of its propagation, some nurseries …

The Quest for Copper Alternatives for Managing Citrus Canker

Jim Rogers Diseases, Research

By Ozgur Batuman, Sanju Kunwar and Ana Redondo There are new products that potentially can be added to a grower’s toolbox in coming seasons for managing citrus bacterial canker. Citrus canker is an infection by a species of bacteria (Xanthomonas citri subsp. citri) that causes fruit blemishes and fruit drop. It makes fruit unsightly and lowers its marketability. Every year, …

Texas Canker Quarantine Expanded Again

Jim Rogers Citrus, Diseases, Texas

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) and the Texas Department of Agriculture (TDA) have established five new quarantine areas for citrus canker in Brazoria, Galveston and Harris counties, Texas. They also expanded two existing quarantine areas for citrus canker in Brazoria, Fort Bend and Harris Counties, Texas, to prevent the spread of the disease. …

Foliar Fungal Disease Round-up for 2022

Jim Rogers Diseases, Florida, Fruit Drop

By Megan Dewdney The 2021 foliar fungal season was an easier than average year. The La Niña weather pattern predicted last fall came to pass, and the spring was relatively dry from January to the end of May with some rain in February and April. While citrus trees in Florida were likely drought-stressed, the dry weather slowed the usual decomposition …

Keep Leprosis From Re-entering Florida

Jim Rogers Diseases, Florida

Citrus leprosis has not been reported in Florida since 1968, but researcher Ozgur Batuman called it “an approaching threat to Florida citrus” in a recent virtual seminar. Batuman, a citrus pathologist at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Southwest Florida Research and Education Center, urged growers to be on the lookout for the disease. According …

Avoid Phytophthora When Planting

Jim Rogers Diseases, Research

Phytophthora infection can lead to severe stunting in newly planted citrus trees, researcher Megan Dewdney told growers and others at a Jan. 19 presentation at the Citrus Research and Education Center in Lake Alfred, Florida. She said stunted trees never thrive or produce adequate fruit. Dewdney is a University of Florida Institute of Food and Agricultural Sciences plant pathologist. She …