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Below you'll find a list of all posts that have been categorized as “Diseases”
By Megan Dewdney Citrus canker can contribute significantly to the loss of fruit prior to harvest. As bloom begins in Florida, it is time to finalize management plans for foliar diseases. For many growers, very aggressive canker management programs are no longer a possibility, however, some management is important. Citrus canker susceptibility of young fruitlets usually starts at the end …
A tool predicting how to protect European citrus from HLB shows how mathematical modeling can help prepare for future plant disease invasions. Europe is currently unaffected by HLB. However, there are increased concerns of an infestation since psyllids that spread HLB have been found in key citrus-producing countries, including Portugal and Spain. In response to the HLB threat, a new …
By Megan Dewdney Despite being in a transition from a La Niña to a neutral El Niño Southern Oscillation phase, Florida has not had warmer than average temperatures in the last two weeks from March 3. Looking at historical trends, temperatures for the last two weeks of February were in the normal range for this time of year. When looking …
By Megan Dewdney As I write this article in January 2025, the world is a chilly place, and it is hard to imagine warm and wet weather in Florida. The predicted weather pattern from now until flowering is moving from La Niña toward neutral. This is predicted to bring above-average spring temperatures with reduced rainfall. This is a hopeful sign …
HLB was recently confirmed for the first time in Arizona, first in an Asian citrus psyllid (ACP) and then in another ACP and citrus plant tissue. The Arizona Department of Agriculture (AZDA) reported the details. On Dec. 16, 2024, agriculture inspectors collected ACP and plant tissue samples from a residential citrus tree in Nogales. The collections were made during a …
The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA/APHIS) recently announced a quarantine for huanglongbing (HLB) in Mississippi as well as updates to Mexican fruit fly (Mexfly) quarantines in Texas. HLB APHIS, in cooperation with the Mississippi Department of Agriculture and Commerce, established a quarantine for the entire state of Mississippi for HLB. The action was taken …
By Ozgur Batuman and Amit Levy Citrus yellow vein clearing virus (CYVCV) was first reported on lemon and sour orange trees in Pakistan in 1988. Since then, the disease has been primarily restricted to Asian countries. However, CYVCV was more recently detected in dooryard citrus in California in 2022. While there is no indication that the virus is present in …
The Citrus Industry section in the March issue of Specialty Crop Grower magazine offers timely information citrus growers won’t want to miss. Now is the time for Florida citrus producers to begin thinking about their disease management programs for the season. Megan Dewdney, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) plant pathologist, offers a foliar disease outlook …
By Megan Dewdney Spring is the time to start thinking about foliar disease management in Florida. Depending on the type of citrus being produced and the market destination, different diseases will be important. POSTBLOOM FRUIT DROP The disease that affects all citrus, particularly oranges, is postbloom fruit drop (PFD). This disease is highly dependent on the weather during bloom. Currently, …
The U.S. Department of Agriculture (USDA) announced an investment of more than $70 million in the Plant Protection Act program. This includes funding of 357 projects in fiscal year 2025. The work will strengthen the country’s defenses against plant pests and diseases, safeguard the U.S. nursery system, and enhance pest detection and mitigation efforts. Part of the funding is going …
Growers in the cold-hardy citrus region should consider fungicide application following snow last week and multiple days of running irrigation for freeze irrigation. That advice comes from Lindy Savelle, executive director of the Georgia Citrus Association, on the heels of historic snowfall recorded across the Southeast. “I’ve heard some people having up to 10 inches of snow where we grow …
Effective immediately, the U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS), in cooperation with the California Department of Food and Agriculture (CDFA), is expanding the sweet orange scab quarantine in the Santa Ana area of Orange County in California. APHIS is expanding this quarantined area by 32 square miles because of a sweet orange scab detection in …
The Applied Research Center for Innovation and Sustainability in Citrus Farming was inaugurated Dec. 12 in a ceremony at the Palácio dos Bandeirantes, seat of Brazil’s São Paulo state government. Its purpose is to combat the main citrus diseases, such as citrus variegated chlorosis, sudden citrus death and above all, citrus greening. The São Paulo Research Foundation (FAPESP), Fundecitrus and …
An area quarantined for huanglongbing (HLB), also known as citrus greening disease, in California was recently expanded. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation with the California Department of Food and Agriculture (CDFA) issued the expansion. The quarantined area in the Mission Viejo area of Orange County expanded by approximately 85 square miles. …
Hurricanes bring immediate tree damage from high winds and torrential rainfall, but storms also can lay the groundwork for citrus disease problems. Soon after Hurricane Milton passed through citrus-growing regions, the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) hosted a webinar that covered various topics including post-storm disease management. CANKER Megan Dewdney, UF/IFAS associate professor of plant …
Citrus canker has long been a presence and concern for Florida’s citrus growers. Growers in North Florida, South Georgia and South Alabama should be wary of its potential spread into the cold-hardy citrus region. Clive Bock, a research plant pathologist with the U.S. Department of Agriculture, spoke about the disease during the recent Cold-Hardy Citrus Meeting at the University of …
The California Department of Food and Agriculture (CDFA) has confirmed the detection of the citrus plant disease huanglongbing (HLB) in inactive citrus acreage in the city of Yorba Linda, Orange County. The detections mark the first time HLB has been confirmed in plant samples on non-residential, non-nursery citrus acreage. The detection site, which is not currently operational or being cultivated …
Agricultural officials recently expanded the areas in California quarantined for citrus greening disease [also known as huanglongbing (HLB)], which is spread by Asian citrus psyllids. The quarantined area in Orange and Riverside counties was increased by a total of approximately 31 square miles. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) in cooperation with the …
Not all citrus disease concerns center around huanglongbing (HLB). While HLB disease garners much of the headlines because of its devastation to Florida’s citrus crop, growers in the cold-hardy citrus region should be mindful of other diseases that can devastate a crop if left untreated. Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist, highlighted some of …
Citrus canker could spread in Florida groves as a result of Hurricane Milton, researcher Megan Dewdney warned. A University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor of plant pathology, Dewdney offered suggestions for dealing with canker at a recent UF/IFAS hurricane recovery webinar. WIND WOUNDS High winds and rain, which were abundant during the hurricane, move …
