Q.Can Tomato Plants Be Watered From The Top
We are experiencing prolonged high temperatures tomatoes are not forming, can I cool plants during the day by misting the foliage?
Certified GKH Gardening Expert
That will not be the best course of action. Be sure that the soil has a chance to dry out at least down to 2 inches between waterings, but most importantly, apply shade cloth to the area to combat heat.
During the hottest portion of the afternoon, make sure you erect a shade cloth, instead of supplying water when it isn't needed. This will avert the problems of overwatering, and disease from spraying.
This article will give you all of the information that you could need for growing tomatoes:
https://www.gardeningknowhow.com/edible/vegetables/tomato/growing-tomatoes-guide.htm