EFFECTS OF BORON AND CALCIUM SPRAYS AND OF MULCH ON CRACKING OF ITALIAN PRUNE

Abstract

Cracking, a disorder of the fruit of Prunus domestica L., cult Italian (Fellenberg) (Italian prune), occurs on any part of the fruit surface and over a wide range of stage of fruit development. Several treatments were examined to reduce the extent of this disorder in five commercial orchards in the Niagara Peninsula of Ontario. Foliar application of calcium reduced the severity of cracking in several orchards. Cracking was related to the calcium concentration in the fruit but not in the leaf tissue. A mulch applied to conserve soil moisture, or foliar sprays of boron, or both, were unsuccessful in preventing this disorder. The severity of cracking varied from orchard to orchard and year to year and was not related to weather conditions.