Whats wrong with my citrus tree? #167457 - Ask Extension

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Whats wrong with my citrus tree? #167457

Asked February 19, 2014, 8:28 PM EST

I have a five year old Satsuma mandarin tree in a large pot that stays on the patio spring, summer and fall and overwinters in our greenhouse. It bears a good crop of fruit and is loaded now but the leaves are starting to curl, yellow and look like bites are being taken out of them. Wonder what is wrong and how to correct?

Clackamas County Oregon

Expert Response

If all the holes are the same as in the image, I doubt something is eating the leaves. Instead, I suspect that a small hole occurred when the leaf was just beginning to develop, then enlarged as the leaf expanded.    

The curled leaf edges make me wonder if an herbicide (weedkiller) was used somewhere in the tree’s vicinity last year while the tree was outdoors.  Spray can move off-target due to a breeze, even if minor,  and/or spray turbulence.  The end effect, here, is that the tree received a sub-lethal dose. 
 

The suspects in this scenario are two commonly used active ingredients in herbicides: glyphosate and 2,4-D.  Roundup (or another product with the active ingredient of glyphosate) might have been used as a fall cleanup, whereas 2,4-D is often used as a broadleaf weedkiller for lawns.  Both of these materials can cause curled leaves.
 

If the damage is from a sub-lethal dose of herbicide, the tree will likely grow out of the effects and new growth that develops later on will be normal.  Also realize that you may see more odd looking new growth before the chemical’s effect wears off, and growth returns to normal.  

All that said, please send an image of the entire tree when your reply to me?  Also include a close-up view of the new growth at a leaf node.




Jean R. Natter Replied February 21, 2014, 1:29 AM EST

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