Diurnal Changes of Leaf and Fruit Water Potentials of Sweet Cherries during the Harvest Period1

Diurnal leaf and fruit water Potentials ( Ψ ) of sweet cherry ( Prunus avium L.) showed that fruit pedicel Ψ was always lower at 6 AM then leaf Ψ but leaf Ψ as usually lower during the day. Varietal differences in Ψ occur but fruit maturity does not appear to have an effect. Minimum fruit pedicel Ψ was reached at about 2 PM and then recovered to the earlier higher Ψ as water uptake occured during the night.