Splitting is a common problem in nectarines, with some varieties more prone to splitting than others. Nectarine skin is thin and fragile. It splits easily because of poor growing conditions or improper handling. Choose nectarine varieties suited to growing conditions in your area and handle nectarines gently during harvest to prevent splitting.
Tree nutrition affects nectarine splitting in several ways. Calcium, magnesium and boron deficiencies cause weak cell formation in the flesh of the fruit and cracking of the fruit follows, notes the University of California Cooperative Extension.
Alternately, an excess of nitrogen fertilizer, especially after fruit set, causes the tree vegetation to grow rapidly at the wrong time. The tree concentrates on green growth while not directing enough nutrition to the fruit.
Nectarines need regular irrigation once the fruit appears. Regular watering allows the fruit to grow at a steady pace. Fruit that is too wet because of rain, fog or dew tends to absorb moisture through the skin. The skin splits to accommodate the rapidly expanding fruit. Mulching under the tree helps retain water and reduces water loss during dry weather.
Hot weather can induce rapid growth, especially following a period of cool temperatures. Periods of drought encourage the fruit to grow too rapidly when water becomes available. The nectarine skin cannot expand rapidly enough to accommodate the growing flesh and the nectarine skin splits.
When the fruit grows rapidly before the pit hardens, the force of the swelling fruit can split the soft pit. This results in the pit opening at the stem end and splitting the fruit. This problem is more common in early varieties and in trees with only a few large fruit. It can be caused by nutritional deficiencies, notes Virginia Tech horticulturalist Richard P. Marini.