 |  |  |  |  |  |  |  |  |
Below you'll find a list of all posts that have been categorized as “Diseases”
In Brazil’s São Paulo citrus belt, infections of fruit by black spot usually occur from petal fall, in September/October, until the end of the rainy season, usually in April. Black spot can reduce production by up to 85%. Some studies have shown that the amount of fungicide applications to control black spot can be established according to the orange variety. …
By Megan Dewdney For foliar diseases, 2022 started off easily with limited outbreaks in Florida because the spring was dryer than average. The same La Niña weather pattern responsible for the dry conditions of the last two springs is predicted to occur again this winter into early spring. The weather pattern is then predicted to become a neutral pattern with …
By Megan M. Dewdney Postbloom fruit drop (PFD) is a sporadic flower disease. It is primarily caused by the fungus Colletotrichum acutatum. While infections only occur on flowers, the fungus is present on trees throughout the year. It survives by producing resting structures on leaves and stems. How the inoculum survives multiple years between infections is still unclear. The fungus …
In Florida, citrus black spot (CBS) is present primarily in commercial groves in five southwest counties (Charlotte, Collier, Glades, Hendry and Lee). The disease can cause up to 60% yield loss in severe situations with little management, researcher Megan Dewdney reported in January. More commonly though, growers with infestations experience fruit drop levels of 10% to 20% in a minimally …
With more growers incorporating compost and organic amendments into their production, weed management is receiving increased attention. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) authors Ramdas Kanissery and Mahesh Bashyal take on this topic in their article in the February 2023 issue of Citrus Industry magazine. While compost and organic amendments can increase soil health and boost …
Researcher Megan Dewdney recently provided updates on citrus canker, postbloom fruit drop (PFD) and algal spot. Dewdney is a University of Florida Institute of Food and Agricultural Sciences associate professor of plant pathology at the Citrus Research and Education Center. CANKERFruit is most susceptible to canker when it is from 3/8 to 1.5 inches in diameter, Dewdney said. The fruit’s …
Two new detections of citrus yellow vein clearing virus (CYVCV) have been confirmed in rural residential citrus trees in the city of Visalia in Tulare County, California. The detections resulted from an ongoing survey and sampling activities conducted by the California Department of Food and Agriculture (CDFA). CYVCV had previously been confirmed in August in the city of Tulare; learn …
Although trunk injection of oxytetracycline hydrochloride (OTC-HCl) has received much recent press for its promise in managing HLB, there is still no silver bullet for the devastating disease. That was part of plant pathologist Ozgur Batuman’s message at a Dec. 10 seminar addressing HLB and other citrus diseases that may exacerbate HLB’s effects on trees. “There is no single effective …
Brazilian citrus association Fundecitrus has alerted growers that proper management to combat citrus canker in orchards begins with leafminer control. The leafminer is a pest that has been present in Brazilian citriculture since 1996. According to Fundecitrus researcher Franklin Behlau, the leafminer does not spread citrus canker disease from one plant to another or even to different parts of it. …
The December All In For Citrus podcast includes a discussion with Michael Rogers, director of the Citrus Research and Education Center, about ongoing efforts growers are making to rehabilitate citrus groves after Hurricanes Ian and Nicole. Rogers also addressed some longer-term research being conducted by the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) to develop trees that …
By Megan Dewdney The story of citrus canker in Florida is unfortunately linked to hurricanes. Canker spreads far and wide with the aid of the storms. Not only can the heavy rains and high winds move the bacterium among locations, but the winds cause wounds in the canopy. Ragged leaves, scoring of leaf surfaces, thorn scratches on branches and more …
The element silicon, known to be beneficial to many plants, is being evaluated for advantageous effects on North Florida citrus and blackberries. Horticulturist Muhammad Shahid discussed the benefits of Earth’s second-most-abundant element (after oxygen) during a recent Cold-Tolerant Citrus Production Workshop in Perry, Florida. Shahid is a University of Florida Institute of Food and Agricultural Sciences assistant professor at the …
Megan Dewdney, associate professor of plant pathology with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), joined the October All In For Citrus podcast to discuss Hurricane Ian and tips on disease management after the storm. Hurricanes weaken citrus trees and spread disease. “If a tree has a full canopy, the wind will put a lot of …
By Megan Dewdney A priority for the Florida citrus industry is evaluating groves for damage and determining the best course of action going forward after the destruction of Hurricane Ian. One of the many considerations is the effect of flooding on root health, particularly if standing water has remained longer than 72 hours. The main diseases are phytophthora foot, crown …
State and federal officials are collaborating in the development of a regulatory response to a new citrus disease in California. Citrus yellow vein clearing virus (CYVCV) was identified in the city of Tulare in March. The discovery is the first instance of the disease in the United States. The California Department of Food and Agriculture (CDFA) and the U.S. Department …
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) faculty recommend actions citrus growers can take to prevent further damage to root systems and future fruit drop following Hurricane Ian. DEAL WITH PHYTOPHTHORAIf standing water has occurred in groves with phytophthora problems, growers should evaluate for root damage and treat accordingly. Floodwaters resulting from heavy rains can severely impact …
A team of researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has successfully identified the CsDMR6 gene, which impacts a citrus tree’s reaction to the citrus canker pathogen. Zhanao Deng and Fred Gmitter, both professors and plant breeders, are members of that team. By editing the CsDMR6 gene in the plant’s DNA to interfere with …
The average incidence of HLB rose from 22.37% in 2021 to 24.42% in 2022 in Brazil’s citrus belt, an annual survey by Fundecitrus shows. That’s an increase of 9.16%. In the regions of Brotas, Limeira and Porto Ferreira, where the incidence was already high in previous years, HLB increased to even more worrying levels of 49.41%, 70.72% and 74.05%, respectively. …
How well reflective mulch, kaolin clay and individual protective covers (IPCs) hold up to HLB, canker and greasy spot diseases was researcher Megan Dewdney’s topic at the 2022 Citrus & Specialty Crop Expo. Dewdney is a University of Florida Institute of Food and Agricultural Sciences associate professor of plant pathology at the Citrus Research and Education Center. The research project …
With citrus industry backing, California state legislators have requested $2.5 million in emergency state funds to help prevent the spread of citrus yellow vein clearing virus (CYVCV). The first finding of the new disease in the United Sates was recently made in Tulare, California. Casey Creamer, California Citrus Mutual (CCM) president and chief executive officer, said the statewide grower organization …
