Fundecitrus recently issued recommendations for leprosis management in Brazil. Leprosis has been expanding in the Brazilian citrus belt for the last six years and is an increasingly significant cause of fruit drop. The disease also causes a reduction in the useful life of the tree, weakened by defoliation and drying of the branches. The main disease management strategy is to …
Sweet Orange Scab Regulations Modified
The conditions under which citrus fruit may be moved interstate from areas quarantined for sweet orange scab (SOS) when destined for processing or packing in a commercial citrus-producing state without a statewide SOS quarantine have been modified. The modification was made by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA APHIS). In 2010, APHIS published Federal …
Citrus Canker Discovered in Georgia
The discovery of citrus canker disease in Georgia last week has prompted industry leaders to caution growers about where they buy their trees. Lindy Savelle, president of the Georgia Citrus Association, said hundreds of trees had to be removed from a grove infected with citrus canker. The trees were not from a Georgia certified nursery. She said the best way …
Keep CTV Under Control
By Amit Levy Citrus tristeza virus (CTV) infects the citrus phloem. CTV infects almost all citrus varieties, but it causes different disease symptoms depending on the virus isolate, the citrus variety and scion-rootstock combination. Florida has three dominant strains of CTV: T36, a decline-causing strain T30, which normally does not cause severe disease VT, a stem-pitting causing strain CTV is …
Citrus Nutrient Deficiencies? There’s an App for That
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
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
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
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 …
Battling Black Spot
By Megan Dewdney Editor’s note: This article originally stated that citrus black spot was in Hardee County. It should have said Hendry County, and has now been corrected. Citrus growers in Florida continue to battle new pests and diseases. They have been learning to manage citrus black spot for the last 12 years. The disease is still localized mainly in …
Comparison of ACP/HLB Management Tools for Citrus Resets
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
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
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
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
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
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 …
The Persistent Problem of Algal Spot
By Megan Dewdney Mid-summer to fall has become algal spot season in my office. The disease is re-emerging in Florida for unknown reasons. While much of the year algal spot is low key and hard to spot, between June and September it is very obvious. So, what is algal spot, should you be concerned, and what can you do about …
Sweet Orange Scab and Citrus Canker Movement Conditions Revised
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
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
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
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, …