Q.Tomato plant to curl down
Why are the leaves of my tomato plant curling down and turning black?

Certified GKH Gardening Expert
It may have wilt or blight. These articles will help you pinpoint which it is and provide more information:
https://www.gardeningknowhow.com/edible/vegetables/tomato/wilting-tomato-plants.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/early-blight-alternaria-tomato-leaf-spots-yellow-leaves.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-late-blight.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-blight.htm