Wondering if anyone can help me identify the problem with my lime tree - there are yellow spots on the leaves that don't rub off, and seem to be part of the leaf itself. See pictures attached.
Thanks in advance for your time
There are a few conditions that can cause this effect.
Bacterial infection can be the most serious...this causes yellow spots that turn brown and spread throuout the plant affecting leaf, wood and fruit.
Citrus Scab also effects the same way.
In both these cases sprays of copper based fungicides will help control.
Red spider can also produce yellowing on leaves as they suck the sap from the leaf from underneath. They are extremely small and you will need a 10 times lens to see them usually.
Just to make it more interesting ...Mineral deficiencies can cause yellowing on the leaf..but the one that makes for yellow spotting between the veins on the leaf is Zinc deficiancy.
Spray of Zinc Sulfate cures that one.
Sorry I can’t be more specific....but it’s a case of watch and check.