Monday, January 25, 2010

Feeling a little ill Mr. Citrus tree?

I would like to start my blog out today on a little different note.
Today is my 18th Wedding Anniversary, I married one of my best friends and have not been disappointed. Happy Anniversary Punky, I Love You!
I would also like to give a shout out to a couple of folks I consider friends, both of whom have blogs you should really check out.
Jenion who runs "Our Park Circle Homestead" http://jenion.blogspot.com/
and Kari who runs "Offshoots" http://scouthort.blogspot.com/
They are very well done and are doing great things with them. Good job you two!

Now, is your Citrus tree feeling a little under the weather? It maybe coming down with a disease.
There are a number of diseases that can infect Citrus. Greasy Spot, Citrus Scab,
Melanose, just to name a few. This article is not long enough to cover all of them. SO, I will cover the two biggest ones right now. Citrus Greening and Citrus Canker.
I have mentioned this before, but it is important enough to mention again.
IT IS ILLEGAL to ship, transport or smuggle Citrus out of the state of Florida!!
The USDA forbids the sale of citrus trees going out of state. I know what some of you are saying, the airports and roadside stands sell the little citrus trees for us to take home. They are using a loophole, on the box that the cute little Key Lime or Lemon comes in states "Grow your own Citrus tree indoors". The law somehow or another does not apply to "Houseplants". One of the biggest problems with this is, what do most people do with their houseplants during the Summer? Yup, they bring them outside and expose them to all the little nasties.
Let me tell you a little about each disease.
Citrus Greening, also called Huanglongbing or yellow dragon disease, is the most serious diseases of citrus in the world. Citrus greening disease is a major threat to the U.S. citrus industry. Other than tree removal, there is no effective control once a tree is infected and there is no known cure for the disease. Greening is spread by an insect, the Asian Citrus Psyllid and possibly by aphids. Infected trees may produce misshapen, unmarketable, bitter fruit. The trees in the orchards usually die 3-5 years after becoming infected and require removal and replanting.
The most characteristic symptoms of citrus greening are a blotchy leaf mottle and vein yellowing that develop on leaves attached to shoots showing the overall yellow appearance. Leaves with citrus greening have a mottled appearance that differs from nutrition related mottling in that greening induced mottling usually crosses leaf veins. Another characteristic is the blotches are not mirror images. If the left side of the leaf vein does not mirror the right side, it could very well be Greening disease. Nutrition related mottles usually are found between or along leaf veins and ARE mirror images.

Notice the uneven blotches on either side of the center vein.


Citrus Canker, caused by the bacterium Xanthomonas axonopodis is a leaf, fruit, and stem spotting disease that affects numerous species, cultivars, and hybrids of citrus and citrus relatives. Symptoms, Young lesions are raised on both surfaces of the leaf, but particularly on the lower leaf surface. The pustules later become corky and crater-like with a raised margin, sunken center and are surrounded by a yellow halo. Fruit lesions vary in size because the rind is susceptible for a longer time and more than one infection cycle can occur on the fruit. Major outbreaks of citrus canker occur when new shoots are emerging or when fruit are in the early stages of development. Frequent rainfall in warm weather, especially during storms, contributes to disease development.
Citrus canker is mostly a leaf-spotting and fruit rind blemishing disease,but when conditions are highly favorable for infection, it causes defoliation, shoot die-back, and fruit drop. In January 2006 eradication of citrus canker affected trees ended, they gave up, saying it CAN NOT be controlled. The disease does not hurt humans, but looking at the picture....I wouldn't want to eat it.

Hopefully, you will never have to deal with these two diseases yourself. Unfortunately, Citrus Greening has been discovered in Charleston County.....I don't have it on my trees, but I am keeping a very watchful eye.
Happy Growing!
Darren

1 comment:

  1. Hi

    My new neighbor is giving away a previous owners tree. I believe it is a citrus tree but can't be positive. I would like to take it but not sure where to plant, how big it get etc...Do you have pictures or direct toward a website that shows different leaves that I might compare mine to? THanks for your help.

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