The leaves on my fruitless mulberry tree are deep green ans curled at the edges
it is watered every day
Is this a new planting? If you have newly planting this tree it certainly could be watering issues or transplant shock. 1 inch of water per week is recommended for optimum care.
If you have an established tree with curling leaves it could be a pest issue.
Inspect the tree carefully for other signs of pest or disease.