Landscape lighting damaged my oranges!
Since I have never read or heard anything on the subject of using landscape lighting around FRUITING trees (some people use lights to protect against frost) I thought people might be interested about my unfortunate experience.
I couldn't figure out why my fruit all seemed to suffer from brown areas with yellow margins on the bottom of the fruit while still green on the tree. Sunburn wasn't an option because all the damage was underneath the fruit where no sun shines. [BTW, I don't think this is UV or heat damage because none of the branches or foliage appears burned (if they had I would have known the cause immediately due to the direction of the light.)]
I had no parasites, nutrition, root or other issues, but thought it looked a lot like oleocellosis. Except these were on the tree, the fruit was still very green, and wind or other trauma shouldn't be so uniform in location on the fruit.
When I opened the fruit the rind in affected (the brownest) areas was paper thin but the rest of the orange was healthy and thick.
I finally figured it out one night when I walked by and saw where the light was hitting. The damage margins were exactly the lit areas and terminated exactly in the shadow cast by the light! These are bright LED low- voltage units, so nothing out of the ordinary. They were about 4 feet from the affected areas.
The take away is DON'T illuminate fruiting trees with landscape lighting while fruit is on the tree. If anyone can tell me why this happens I might be able to modify the lighting to stop the damage. Until then, the trees are now lights out!