Federal and state officials recently expanded the area quarantined for citrus greening disease, also known as huanglongbing or HLB, in California. They expanded the quarantined area in the San Clemente area of Orange and San Diego counties by 81 square miles. The action was taken by the U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation …
Putting Down Brown Rot
By Megan Dewdney Sometimes there is an unfortunate coincidence between the timing of fruit changing color and rain events. This can set up a situation where brown rot occurs unexpectedly and growers need to stop the disease after it has begun. CONTROL OPTIONS By this time of year, the traditional brown rot control measures are less effective. These are primarily …
Proper Site Selection Essential for Phytophthora Prevention
Vulnerability of citrus trees to phytophthora root rot is a concern for cold-hardy growers. But there are precautions that producers can implement that will guard against infection buildup. One of those precautions includes site selection and not planting trees in poorly drained locations, according to Jonathan Oliver, University of Georgia assistant professor and small fruits pathologist. “Site prep is really …
Greasy Green and Its Management
A citrus disorder called greasy green has plagued Florida grapefruit producers for several years, causing a significant reduction in profits. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Associate Professor and Extension Specialist Megan Dewdney discussed the disorder and its management at the Citrus & Specialty Crop Expo in August. Dewdney works at the UF/IFAS Citrus Research and …
Phytophthora Root Rot a Concern in the Cold-Hardy Region
Phytophthora root rot’s impact on young citrus trees is concerning for groves in the cold-hardy citrus region of North Florida, South Georgia and South Alabama. Newly planted trees are more vulnerable to the disease than older, established trees, says Jonathan Oliver, University of Georgia assistant professor and small fruits pathologist. He discussed the disease’s impact during the Citrus Grower’s Summer …
Citrus Greening Quarantine Expanded in California
Federal and state agriculture officials have expanded the quarantine for citrus greening in the Perris area of Riverside County in California by 33 square miles. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation with the California Department of Food and Agriculture (CDFA) expanded the quarantine. The measure parallels the intrastate quarantine that CDFA established …
Rootstock Influence on Witches’ Broom Disease of Lime
An Iranian study in controlled greenhouse conditions has enhanced the understanding of the influence of rootstocks on limes infected with witches’ broom disease of lime (WBDL). The study has also led to the acknowledgement that WBDL management may require tolerance of both scions and rootstocks. Authors of an article about the study are Samaneh Raheb, Sina Noorizadeh and Morteza Golmohammadi, …
Preventing Citrus Greening Establishment in Georgia Groves
Citrus greening disease has yet to find its footing in Georgia. But that doesn’t mean it can’t or won’t eventually. Mary Sutton, University of Georgia assistant professor and citrus Extension specialist, discussed the ramifications of citrus greening during the recent Southeast Citrus Update in Lyons, Georgia. “If we get greening established here, we’ll start seeing lower and lower production on …
Honeymoon Phase for Georgia Citrus Production
Georgia citrus growers are still in the honeymoon phase of production with regards to disease, said Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist. While established groves in Florida have had to deal with disease buildup for decades, disease has yet to be problematic for South Georgia citrus production. But that could be changing. “With respect …
Citrus Canker Quarantines Established and Expanded in Texas
The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) announced June 26 that it was establishing and expanding the quarantined areas for citrus canker in Texas to prevent the spread of the disease. The action was taken in cooperation with the Texas Department of Agriculture (TDA). APHIS established a new quarantined area in the Harlingen Area of …
Best Practices for Brown Rot Management
By Megan Dewdney The Florida rains have finally come this summer, just in time for early-season fruit to start the maturation process. This means there is some risk of brown rot in early sweet oranges and grapefruit. Much of Florida has been getting summer storms, wetting the soil. While this is excellent in general, the downside is that it allows …
Citrus Black Spot Spreads to More Florida Counties
Citrus black spot (CBS) quarantines have been established for the first time in Florida’s DeSoto and Highlands counties. In addition, sections of other counties have been added to the existing CBS quarantine in Florida. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA/APHIS) in cooperation with the Florida Department of Agriculture and Consumer Services Division of Plant …
New Sweet Orange Scab Quarantine Established
A new quarantine area for sweet orange scab (SOS) was recently established in the Burbank area of California’s Los Angeles County. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA/APHIS) in cooperation with the California Department of Food and Agriculture announced the quarantine area. The 91-square-mile quarantine was established because of an SOS detection in a plant …
Brazilian Biotech Company Targeting Citrus Pathogens
With support from the São Paulo Research Foundation (FAPESP), Ideelab is developing more efficient strategies to combat pathogens that threaten citrus. The work of Ideelab, a São Paulo startup company, is based on the principle that plants communicate with microorganisms through specific molecules called effectors. Effectors are peptides and proteins that are produced naturally and interact with the pattern recognition …
Increased Rainfall Impacts Florida Citrus
Recent rainfall has been a welcome sight for Floridians, but it can be a concern for the state’s citrus growers who are producing next year’s crop. Chris Oswalt, University of Florida Institute of Food and Agricultural Sciences citrus agent, cautions growers about citrus canker amid the increased moisture in the region. “With rainfall, you need to be concerned about those …
Dealing With Disease: Canker, Black Spot and More
As the rainy season in Florida is set to begin, we caught up with Megan Dewdney to discuss citrus canker and other disease issues. Dewdney is a plant pathologist with the University of Florida Institute of Food and Agricultural Sciences. Q: How has the prevalence of citrus canker been in Florida in the past year or so? A: Dewdney: Citrus …
What To Do About Pesky Red Patches From Algal Spot
By Megan Dewdney Every summer, a low rumble about algal spot reaches my ears. And every year, someone discovers it in their Florida grove for the first time. While this is a disease that is not always at the top of mind for growers, when you see it for the first time, it can be dramatic. DISEASE SYMPTOMS Algal spot …
Citrus Disease Research Funding Applauded
Three citrus grower associations applauded Chairman GT Thompson and the U.S. House Agriculture Committee for including critical funding for the Emergency Citrus Disease Research and Extension Program in the recent budget reconciliation draft. The associations were California Citrus Mutual (CCM), Florida Citrus Mutual (FCM) and Texas Citrus Mutual (TCM). The investment represents a vital commitment to the long-term health and …
Branch Rot Hits Brazilian Orchards
The disease branch rot is worrying Brazilian citrus growers because of its recent increased occurrence in orchards. Branch rot is also called peduncular rot, branch gummosis or bot gummosis. The main reason for the disease’s occurrence is stress caused to citrus plants by high temperatures, severe periods of drought and attacks from other diseases, such as greening. Fungi of the …
Reduce Fruit Drop From Citrus Canker
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 …