These are an heirloom variety (tomande), I have tried giving them less and more water with no difference.
I have 3 plants of this variety and they are all suffering the same problem.
It starts on the lower leaves with little spots that look a little see-through, the edges of the leaves start to curl and then turn brown until eventually the leaf turns crispy and brittle.
I am growing 3 other varieties all in the same area which do not suffer this problem.
Any help would be greatly appreciated.
![new4] (https://i.sstatic.net/middQ.jpg)