Given the fact that:  As humidity increases, the water potential gradient across the inside and outside the leaf become more equal, and so the rate of transpiration decreases.  Answer the question:   Joe noticed that the humidity inside the greenhouse was getting very low, so he turned the sprinklers on to make it more humid. Thus, when the water potential gradient across the inside and outside of the leaf becomes equal, the rate of transpiration will increase or decrease.?
The answer to this question is:
increase