Tag Archive: Canker

Citrus Canker in Northwest Florida

Citrus Canker in Northwest Florida

Citrus canker symptoms on twigs, leaves and fruit. Photo by Timothy Schubert, FDACS

In November 2013, citrus canker was found for the first time in the Florida panhandle in Gulf Breeze in southern Santa Rosa County. The Florida Department of Agriculture and Consumer Services (FDACS) tested and confirmed the disease on grapefruit trees in a residential landscape. Since that time, citrus canker has been confirmed on citrus trees at 27 more locations in Gulf Breeze. To my knowledge it has not been found in any other location in the panhandle. Not yet.

Citrus canker lesions on leaves are raised, rough and visible on both sides of the leaf. Photo by Timothy Shubert, FDACS.

Citrus canker is a serious bacterial disease that only infects citrus trees. It will not infect any other plant species nor is it a threat to human health. This highly contagious disease has no cure as yet. Severely affected trees experience substantial leaf and premature fruit drop and serve as a source for infecting other citrus in the area. The disease spreads through wind, rain and transportation of infected plant material from other locations.

We do not know how the disease came to infect trees in our region. The disease could have been spread through infected fruit or trees brought here from areas where the disease is established, such as central or south Florida.

What should you do if you suspect your citrus is infected with this disease?

Citrus canker lesions can appear in the mines left by the citrus leafminer pest. Photo by Timothy Schubert, FDACS

  1. Look at Homeowner Fact Sheet: Citrus Canker for more information.
  2. Leave the tree in place in your yard and call the Division of Plant Industry at FDACS at 1-888-397-1517 for a free inspection and testing of your citrus trees.
  3. Consult your local Horticulture Extension Agent for more information and control/removal strategies.
  4. Proper removal of infected trees is recommended to prevent the spread of citrus canker but is not mandatory.

 

For more information please see:

Save Our Citrus Website

UF IFAS Gardening Solutions: Citrus

Citrus Culture in the Home Landscape

UF IFAS Extension Online Guide to Citrus Diseases  

 

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Author: Mary Derrick – mderrick@ufl.edu

Residential Horticulture Extension Agent for Santa Rosa County

Mary Derrick

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2017/05/12/citrus-canker-in-northwest-florida/

Panhandle Citrus Producers Need to Symptoms of Canker and Greening

Panhandle Citrus Producers Need to Symptoms of Canker and Greening

Florida’s citrus producers, as well as backyard growers have battled detrimental issues like hard freezes and storm damage over the years.  However, in recent years, emergent bacterial diseases known as citrus canker and citrus greening have been devastating Florida’s citrus crops.  Although these diseases are not yet a major issue in the Panhandle, it’s important to be aware of the characteristics of these diseases.

Citrus Canker

In 2013, the first case of citrus canker in the Florida Panhandle was found in southern Santa Rosa County. Citrus canker is usually produced under moist conditions and easily dispersed by windblown rains. The bacterium either enters through the leaves or fruit, especially through a wound.  Damage from the citrus leafminer is a notorious origin of the disease. Symptoms will appear as tiny blisters on both sides of the leaves. As time goes on, the blister will turn into pronounced, raised brown rings. In severe cases, the condition can appear on stems and fruit (Figure 1).

citrus_canker

Figure 1: Citrus Canker. Photo Credit: Mongi Zekri, UF/IFAS.

Citrus canker can be spread by contact with clothes and pruning equipment, so its important to sanitize field equipment after any thought of possible contact. There is limited chemical control for citrus canker, but a copper compound fungicide will help stifle the condition.

Citrus Greening

Another condition known as citrus greening or HLB (Huanglongbing), is particularly a menace to citrus groves in South Florida. Citrus greening is caused by an insect known as the Asian citrus psyllid. In 1998, the insect was found in a few counties on the east coast of Florida. By 2001, the insect had been found in 31 counties, nearly half the state.

Citrus greening works a bit differently than citrus canker. As the psyllid feeds on the leaves of the tree, the bacterium is released. The bacterium lives and thrives in the tree’s phloem. The phloem is the living tissue of the tree that transports nutrients throughout. Unfortunately, once infected, the tree will steadily decline in health. Fruit production will drop in number, size and taste each year until the demise of the tree. Sadly, there are no commercially avaiable citrus species that are immune to the bacterium.

Symptoms of citrus greening often begin by the yellowing of the leaves along the veins. A green tie-dye look to the leaves is a typical sign (Figure 2). To make matters worse, it’s difficult to diagnose. These symptoms can easily be confused with nutrient deficiency. Lab analysis is required for accurate identification. There are no chemical treatment options either, only methods to keep the condition from spreading. A non-systemic pesticide like malathion or neem oil, a less toxic repellent, can help combat the spread of the disease.

Figure 2: Citrus Greening. Photo Credit: Mongi Zekri, UF/IFAS.

Figure 2: Citrus Greening. Photo Credit: Mongi Zekri, UF/IFAS.

Citrus canker and citrus greening are serious diseases that threaten Florida’s citrus crop. Controlling the source of the bacterium is extremely important. Keep in mind that the most common vector regarding the spread of these diseases is humans transferring citrus from one region to another.

Important!

If you suspect that your citrus trees may have either condition, please contact the FDACS Division of Plant Industry’s Helpline Center at 1-888-397-1517 before taking any action to reduce accidental spread of this disease. 

 

For more information, please visit the UF Citrus Research and Education Center website, or contact your local county extension office.

 

Supporting information for this article can be found in the UF/IFAS EDIS publications:

 

An Equal Opportunity Institution. UF/IFAS Extension, University of Florida, Institute of Food and Agricultural Sciences, Nick T. Place, Dean for UF/IFAS Extension. Single copies of UF/IFAS Extension publications (excluding 4-H and youth publications) are available free to Florida residents from county UF/IFAS Extension offices.

 

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Author: Ray Bodrey – rbodrey@ufl.edu

Gulf County Extension Director, Agent II Agriculture, Natural Resource & Community Development

Ray Bodrey

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2016/08/06/panhandle-citrus-producers-need-to-symptoms-of-canker-and-greening/

Citrus Canker Found in Northwest Florida

Citrus Canker Found in Northwest Florida

2013-11-21 Citruscanker_SR_clusterleaves_lesions

Citrus Canker lesions on leaves. Photo Credit: Beth Bolles, UF IFAS Extension – Escambia County

Authors: Blake Thaxton & Mary Derrick, UF/IFAS Extension – Santa Rosa Co. Mikaela Anderson, FDACS Division of Plant Inspection

Citrus canker is a serious disease of citrus trees that was recently confirmed for the first time in southern Santa Rosa County. Canker is caused by the bacterial pathogen Xanthomonas citri subsp. citri.  Citrus canker has been a major pest of citrus in south and central Florida. It is economically damaging to the commercial industry and is also problematic to homeowners because it causes premature fruit drop, discolored fruit, and eventually causes the tree to become unproductive.

Canker was first introduced in 1912 into Florida and was declared eradicated in 1933. The disease was found again in the Tampa area on citrus in 1986.  It was declared eradicated in 1994, but once again was found in 1995 in Miami.  This time, the disease was not successfully eradicated in part because hurricanes made the disease too widespread to control. Despite its prevalence in south and central Florida, this disease has not been known in the Panhandle. The University of Florida and the Florida Department of Agriculture and Consumer Services’ Division of Plant Industry will be assessing the extent of the disease in Santa Rosa County in the coming months.

2013-11-21 citruscanker_SR_leafminer_lesions

Lesions growing through the channels formed by the Citrus Leafminer insect. Photo Credit: Beth Bolles, UF IFAS Extension – Escambia County

How might you know if your citrus is infected by canker?  One of the best indicators of canker is the presence of lesions, diseased spots, on the upper and lower surfaces of the leaves.  The lesions will be raised and have a rough surface and will be surrounded by yellow halos. Similar lesions may be present on the fruit and stems as well.

Important!

If you suspect that your citrus trees may have citrus canker please contact the Division of Plant Industry’s Helpline Center at 1-888-397-1517 before taking any action to reduce accidental spread of this disease. 

2013-11-21 Citruscanker_SR_Stemlesion

Lesions formed on the stems. Photo Credit: Beth Bolles, UF IFAS Escambia County Extension

The disease is highly contagious to citrus only and spreads rapidly through wind, rain and via people on their hands, clothes, and tools.  Do not transport any plant material that shows symptoms of canker.  Decontamination practices should be used when going from one citrus tree to the next.  Hand washing with soap and water for 20 seconds or more to eliminate bacterium on the skin should be practiced as well as using alcohol-based hand sanitizer.  Pruning tools or other tools that come into contact with citrus should be disinfected by a fresh solution of 1 ounce of household bleach to 1 gallon of water.  An old or dirty bleach solution is not able to disinfect because the chemical is no longer active.

Warning!

Do Not Move a Plant Infected with Citrus Canker.  Please Call your local Extension Office for further instructions

 

For more information on citrus canker:

              (The University of Florida IFAS Citrus Canker website provides a photo gallery of disease symptoms & information about the disease)

PG

Author: Blake Thaxton – bthaxton@ufl.edu

Santa Rosa County Extension
Agent I, Commercial Horticulture

Blake Thaxton

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2013/11/25/citrus-canker-found-in-northwest-florida-2/

Citrus Canker found in Northwest Florida

Citrus Canker found in Northwest Florida

2013-11-21 Citruscanker_SR_clusterleaves_lesions

Citrus Canker lesions on leaves.  Photo Credit: Beth Bolles, UF/IFAS Extension – Escambia County

Blake Thaxton & Mary Derrick, UF/IFAS Extension – Santa Rosa Co.
Mikaela Anderson, FDACS Division of Plant Inspection

Citrus canker is a serious disease of citrus trees that was recently confirmed for the first time in southern Santa Rosa County. Canker is caused by the bacterial pathogen Xanthomonas citri subsp. citri.  Citrus canker has been a major pest of citrus in south and central Florida. It is economically damaging to the commercial industry and is also problematic to homeowners because it causes premature fruit drop, discolored fruit, and eventually causes the tree to become unproductive.

Canker was first introduced in 1912 into Florida and was declared eradicated in 1933. The disease was found again in the Tampa area on citrus in 1986.  It was declared eradicated in 1994, but once again was found in 1995 in Miami.  This time, the disease was not successfully eradicated in part because hurricanes made the disease too widespread to control. Despite its prevalence in south and central Florida, this disease has not been known in the Panhandle. The University of Florida and the Florida Department of of Agriculture and Consumer Services’ Division of Plant Industry will be assessing the extent of the disease in Santa Rosa County in the coming months.

Lesions growing through the channels formed by the Citrus Leafminer insect.

Lesions growing through the channels formed by the Citrus Leafminer insect. Photo Credit: Beth Bolles, UF/IFAS Extension – Escambia County

How might you know if your citrus is infected by canker?  One of the best indicators of canker is presence of lesions, diseased spots, on the upper and lower surfaces of the leaves.  The lesions will be raised and have a rough surface and will be surrounded by yellow halos. Similar lesions may be present on the fruit and stems as well.

Important!

If you suspect that your citrus trees may have citrus canker please contact the Division of Plant Industry’s Helpline Center at 1-888-397-1517 before taking any action to reduce accidental spread of this disease. 

Lesions formed on the twigs.

Lesions formed on the stems. Photo Credit: Beth Bolles, UF/IFAS Escambia County Extension

The disease is highly contagious to citrus only and spreads rapidly through wind, rain and via people on their hands, clothes, and tools.  Do not transport any plant material that shows symptoms of canker.  Decontamination practices should be used when going from one citrus tree to the next.  Hand washing with soap and water for 20 seconds or more to eliminate bacterium on the skin should be practiced as well as using alcohol-based hand sanitizers.  Pruning tools or other tools that come into contact with citrus should be disinfected by a fresh solution of 1 ounce of household bleach to 1 gallon of water.  An old or dirty bleach solution is not able to disinfect because the chemical is no longer active.

Warning!

Do Not Move a Plant Infected with Citrus Canker.  Please Call your local Extension Office for further instructions

 

For more information on citrus canker:

              (The UF Canker website provides a photo gallery of disease symptoms & information about the diesease)

 

 

PG

Author: Blake Thaxton – bthaxton@ufl.edu

Santa Rosa County Extension
Agent I, Commercial Horticulture

Blake Thaxton

Permanent link to this article: http://franklin.ifas.ufl.edu/newsletters/2013/11/23/citrus-canker-found-in-northwest-florida/