Mexican Plum Leaf Curl
I have a mexican plum tree which I planted last year. It was a rather sad specimen, but I planted it anyway. This spring it put out plenty of leaves and grew vigorously, but all of its leaves are curled. I don't see any signs of the usual fungal culprit (peach leaf curl) nor any sort of insect infestation. Every leaf on the tree is pretty much equally curled. Maybe someone can give me an idea what other things I should think about and what I might do about it, if anything needs to be done.
McLennan County Texas
There are several different things that will cause the leaf on a plum tree to curl. I dont see damage related to herbicide drift in the picture. My next thought would be aphids. Aphids are somewhat pear shaped insects that often will have a rapid increase in their population and feeding activities of this elevated population will cause the leaf to curl. If this is a problem that continues you could apply a dormant oil. There is not one specific dormant or horticultural oil that is recommended, they all operate basically the same way. You can purchase that dormant/horticultural oil at any ag feed store, or gardening center.
Right, I just didn't see any aphids. I realize they're rather small, but I was looking pretty carefully. Perhaps I have missed them. Anyway, thanks for the response. I'll see how it goes and try applying some oil at the proper time.
I compared your pictures to peach leaf curl and damage of plum pockets and they are not the same. Unlike leaf curl in peaches, which is caused by a fungus, leaf curl in plums is caused by an infestation of the plum leaf curl aphid, Brachycaudus helichrysi. This insect sucks tree fluids from plum leaves, causing them to curl. Colonies of these aphids will mass inside the curled leaves on which they are feeding. If this has been a re-occuring problem then I would apply neem oil, pyrethrins, or imidacloprid.