Chrysanthemum leaves white patches
I have Chrysanthemums plants in my garden and some of them are developing white patches all over the leaves. It is fast spreading to all the plants. I tried using Neem extact spray but of no use. Can you please guide me
It is possibly powdery mildew or downy mildew on the leaves. Without photos and description of the growing conditions we can only guess.
There are different types of neem extract products. If you have an Azadirachtin concentrate it is good as an insect pest repellent but not as a fungicide. Neem oil products have some fungi prevention/suppession properties but are not effective for advanced infections.
You should look for a fungicide product that lists powdery mildew and downy mildew as a target disease. You postal code indicates that you are in Hyderabad India. I do not know what products are available there.
If the white patches are fuzzy mounds, then the plants may have mealybugs, an insect pest.