Question
what is wrong when the leaves of the tomatos curl updci5n

Answer
Marion:

This condition normally happens when you have a fungus. I suggest that you buy an all purpose fungicide and spray every 3 days for 9 days. It is possible that you could have nematodes which is a small parasite that attaches to the roots of the plant. If this is the case then there is no known cure. When selecting tomato seeds always select the nematode resistant ones.

Best wishes and good growing.

Don Battles
Chiang Rai Thailand