I have what appears to be leaf curl in my tomatoes, potatoes and sunflowers. One tomato plant already appears dead and others badly injured. Several potato plants, only a week and a half out of the ground, also appear badly affected. Last year this was confined to the sunflower plants.
Leaf Curl in Tomatoes, Potatoes and Sunflowers
Certified GKH Gardening Expert
This could be a white fly infestation, verticillium wilt, or environmental issues.
Crop rotation is an important practice and can help reduce or eliminate some of these damaging plant viruses.
Since you had issues last year with the sunflowers, I would also suggest a soil test.
This will help you determine what fertilizers would be most beneficial to your garden.
You may also want to treat the plants with Neem Oil. This works as both a fungicide and insecticide.
Here are a few links for you.