Question: lemon tree with diseased leaves
Hi, my lemon tree that until last winter has been producing fruit on an industrial level for a few months has all the leaves shriveled and with a kind of black and white powder on it ... how can I remedy it? Could massive pruning of branches be useful? Thank you
Answer: lemon tree with diseased leaves
the white powder, present on your lemon, could be powdery mildew, which develops when the night is very cool and the days definitely rainy or damp; it is a fungal disease, which dramatically ruins the foliage; it is treated by treating the plant with sulfur-based products (only if it is not in flower), which dry the water that remains on the leaves and kill the spores of the fungi that attacked them.
If in addition to hatred there is also a black powder, it could be fumaggine; also in this case it is a fungal disease, which usually develops on honeydew produced by insects, such as mealybugs or aphids. So, if your plant develops some fumaggini, the wrinkled leaves are also hosting insects, which must be eradicated to eliminate also the fumaggine.
It is probably the climate that is not helping you, since the spring has been very cold and rainy; I believe that a good sulfur-based treatment, and the climate that is becoming decidedly warmer and drier, will help you a lot in the care of your lemon. If you also see insects on the foliage, you can try to drive them away using a pyrethrum or nettle insecticide; or you can draw them away from the plant using the appropriate adhesive traps, which are based on the fact that some insects love the yellow or white color, and therefore they approach the trap, remaining trapped.