Sweet cherry production is plagued by the problem of fruit cracking, with even 25% cracked fruit being considered uneconomic. A new model called the ‘Zipper model’ has been developed to explain this phenomenon, and it involves calcium. While calcium has been shown to reduce cracking, the ideal application time is unknown, and the process can be expensive. The best solution to this problem would be to use resistant cultivars, but as of now, no completely resistant cultivars have been identified, though there are differences in tolerance levels. However, genetic research has revealed interesting QTLs that could be used to breed cultivars with better cracking tolerance. This is