Abstract A technique is described whereby osmotic potential, turgor potential and total fruit water potential can be determined quickly in the field with the aid of a pressure bomb, a hand held refractometer, and a percent soluble solids to osmotic potential conversion chart. A unique inverse linear relationship between percent soluble solids and osmotic potential was found for each fruit species. Application of this technique to rain cracking of ‘Napoleon’ sweet cherries (Prunus avium L.) shows that cracking is not strictly related to percent soluble solids, osmotic, turgor, or fruit water potential. This suggests that the degree of cuticular permeability, cuticular strength, cell wall strength or other factors may be of greater importance in determining cracking susceptibility than water potential parameters.