Citrus Canker: What you need to know by Ashley Grubb

Citrus canker is a term that we’ve been hearing a lot about lately and one that is relatively new to the ears of our customers. We’ve been getting lots of questions lately, and it seems like the past few years have been filled with all kinds of citrus-related news that, as consumers, we wonder if we should worry about.

As many of you may already know, citrus greening is a disease that has lead to a quarantine restricting the movement of citrus trees in and out of counties around the Houston area. This quarantine has been set in place primarily as a precaution to prevent infection, isolate, reduce, and eradicate the disease. Last year, added to that, was a quarantine area in Harris County for citrus canker.

So why even grow citrus trees then?! Because they’re beautiful plants that produce bumper crops of tasty fruit, and the quarantines aren’t as terrible and citrus-world-ending as they sound. By exercising a little precaution and abiding by the rules of the Department of Agriculture you should have absolutely no problem, and can continue to enjoy your home-grown orange juice!

So what is citrus canker you ask? It’s an infection caused by a bacterium that can be spread through wind and rain. The bacterium looks for injuries on a citrus tree where it can enter its leaves or stems. Damage caused by leaf miners- the tiny insects that make citrus leaves distort and curl up while leaving little clear race track lines all over the surface- is one of the best ways for the bacterium to enter its citrus host. However, it can also be spread by contact, so it’s important to keep your pruners clean and sterile if trimming multiple citrus trees (which is good practice anyway).

How do you know if your citrus tree is infected? It probably isn’t, but, symptoms include leaf spotting and fruit rind blemishing.

 

 

 

The disease can also cause defoliation, shoot dieback, and fruit drop. It isn’t the same thing as citrus greening, and the symptoms can also be confused with citrus bacterial spot, citrus scab, leprosis, malnutrition, bird damage, and greasy spot. If something looks off with your tree, don’t despair! It’s probably something minor and easily treated. Consult an expert before you assume the worst!

Since there is no cure for the bacterium, prevention is the best approach. Growers are working diligently to prevent the disease by growing citrus under insect screens. Their greenhouses have airlocks on both ends and they have installed personal wash stations for employees, so you can be sure that the citrus trees you purchase from Enchanted are perfectly healthy.

Once you bring your trees home, follow the instructions on the labels of any chemicals you use, and don’t take your citrus trees on road trips! Controlling the damage caused by leaf miners is the best preventative measure you can do. Enchanted has all of the products you need to kill leaf miners and we have also brought in citrus leaf miner traps to help you determine the most effective times to treat- come visit us and stock up!

 

For more information on leaf miners visit:

 

http://aggie-horticulture.tamu.edu/galveston/Gardening_Handbook/PDF-files/GH-006–citrus-leafminer.pdf

 

An early spring preventative spray of copper fungicide might not be a bad idea as well. Also, just be sure to observe your citrus tree if you’re within with citrus canker quarantine boundary.

 

For more information, and to view the quarantine map visit:

https://www.texasagriculture.gov/RegulatoryPrograms/PlantQuality/PestandDiseaseAlerts/CitrusCanker.aspx

 

We have lots of great citrus varieties this spring and they’re all about to bloom! Come see and smell one of the reasons why we love them so much!