CRACKING SUSCEPTIBILITY OF SWEET CHERRIES IN THE UNITED KINGDOM IN RELATION TO CALCIUM APPLICATION AND COVER SYSTEMS

This study evaluated the viability of orchard covering systems for new plantings and the benefit of Ca²⁺ sprays for older plantings in relation to rain cracking for ‘Van’, ‘Colney’ and ‘Summersun’ sweet cherry on ‘Colt’ rootstock. Cracking index results were related to biochemical analyses of fruit quality, osmolarity and cuticle thickness. In general, Ca²⁺ applications reduced cracking more than orchard covers, though in some cases fruit size was smaller. Increased cracking of `Colney’ fruits under covers may have been due to increased collection of rainwater in the rootzone. As this report is from a single year’s study, further research into Ca²⁺ application techniques and the effect of Ca²⁺ on fruit size is necessary to before investments into overhead irrigation systems for Ca²⁺ are warranted.