Why are my Basil leaves turning yellow?

Question

The leaves that turn yellowish, have what appears to be dirt, or a dust on the bottom side of the leaf. Anyone know what this is? Is there anything I can do to remedy the situation?

Answer 1

this is a type of fungal or mold infection, spray with anti fungal/mold product, lots of different ttypes at garden centers.

Answer 2

Probably mold.

Answer 3

Too much water,  will cause leaves to yellow.   If the plant is iin a pot that is too small, you are virutally drowning it .