Physiological and genetic factors influencing fruit cracking

One of the main disorders that widely limit fruit quality and quantity is fruit cracking or splitting that is observed on the fruit skin and flesh in the preharvest phase. Besides, cracking can occur during postharvest in some fruits, mostly attributable to the environmental conditions of storage. Value of cracked fruits is reduced and these fruits are not marketable because of the poor fruit quality. Many fruits such as apple, sweet cherry, grape, plum, pomegranate, grape, persimmon, litchi, avocado, pistachio, citrus, banana as well as tomato can crack or split. There are many factors that influence fruit cracking. In this work, genetic, morphological, environmental and physiological aspects of fruit cracking are reviewed. Under the same environmental conditions, fruits from different cultivars show differences in cracking susceptibility. Some correlations have been observed between susceptibility of fruit cracking and some fruit traits (fruit shape, fruit size, fruit firmness; anatomy and strength of the fruit skin, stomata in fruit skin, cuticular properties, osmotic concentration, water capacity of the fruit pulp and growth stage of the fruit). Also, orchard management (such as irrigation and nutrition) and environmental condition (such as temperature, wind and light) can influence fruit cracking. Besides, fruit cracking is quantitative trait and is controlled by several genes. The best way to reduce fruit cracking at present would be a suitable orchard management that takes into account and try to minimize stress of the water, nutrition and physiological factors that contribute to fruit cracking. Also, the most resistant cultivars to fruit cracking that have desirable fruit quality can be selected for cultivation.