Epinastic leaf curling

Epinastic leaf curling involves the downward bending of petioles or leaf blades. In tomatoes, this can be caused by, among other things, the effects of ethylene, overwatering, or root damage. It should not be confused with physiological upward leaf curling, which can occur after heat, drought, or severe pruning. Viruses and herbicides can also cause similar deformities, so diagnosis should take into account other symptoms and growing conditions. It is advisable to examine new growth, check the growing medium and treatment history, and isolate any plant showing additional signs of infection until the problem is diagnosed.