Tomatoes can develop a physiologic disorder called leaf roll, which is caused by high temperatures and, possibly, water stress. Physiologic leaf roll is not a problem, and fruit set will return to normal when high temperatures cease.
Suggested control measures which may help avoid leaf roll in a fall crop include:
Plant tomatoes in a well-drained soil.
Fertilize according to soil test recommendations and do not over fertilize, particularly with nitrogen containing fertilizers.
Avoid deep and close cultivation especially in dry weather.
Maintain uniform soil moisture through irrigation, supplying an inch of water per week.
Mulch tomatoes with plastic or organic material.
