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Q. Who is Mr. Smarty Plants?

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Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

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Wednesday - November 14, 2007

From: Glendale, AZ
Region: Southwest
Topic: Diseases and Disorders
Title: Navel orange disease problems
Answered by: Barbara Medford

QUESTION:

I live in Glendale, Arizona. I hav a mature miniature navel orange tree. This year it has lost a considerable amount of leaves. Also the fruit all has a large yellow spot. It looks pitiful. What should I do?

ANSWER:

We found an excellent site on dealing with problems with the navel orange trees. We really tried to find one from Arizona but couldn't, so you'll have to accept this Texas Cooperative Extension site, instead. Then, if you're really dedicated to find a solution, go to this site, "Diagnosing common citrus problems", and see what you can find that fits your situation.

As in a great many plant problems, especially, it would seem, with trees, plant stress gets a lot of the blame. One reference said that orange trees should be fertilized 6 times a year, starting in early March through August/September. Maybe your tree is just hungry. Or, if the trunk is not above the surface of the surrounding garden, or there is mulch spread over the root zone, the tree may be developing root rot or foot rot. Charming terminology. It look to us like the experts were pretty nonchalant about most of the problems with navel oranges, with comments like "not worth treating", etc. It's up to you to plow through that chart on citrus problems and see if it's worth it to you.

 

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