Fig. 2 Simultaneous equilibration of leaf psychrometers attached to corn. One psychrometer was attached to a surface without abrasion, the other was attached after abrasion with sandpaper. The experimental chamber light was turned on 8 h prior to the test and turned off approximately 4 h into the test. The approximate water potential () of the corn leaf during the light period is between -0.5 and -0.6 MPa