I have this strange issue with my tomato plants in that the leaves appear to
be curling horizontally, not vertically - like closing a hand. They are
still growing and a couple of flowers have come out, but I am concerned that
they have some fungal disease and that I will have to pull them as it is
getting late in the season to try and plant some more (I live in Australia)

any advice would be greatly appreciated.

Denise