Calcium nutrition affects cold hardiness, yield, and fruit disorders of apple and pear trees

Foliar sprays of calcium chloride (CaCl2) and to a lesser extent, soil applications of calcium nitrate [Ca(NO3)(2)] fertilizer, increased calcium (Ca) concentrations in leaves and fruit of apple, (Malus domestica) and pear (Pyrus communis L.) trees. For most years, CaCl2 sprays or Ca(NO3)(2) fertilizer increased cold hardiness of 'Anjou' pear trees, and reduced the incidence of fruit disorders (alfalfa greening and cork spot of pears and bitter pit of 'Delicious' apples). Yield of 'Anjou' pears was usually increased with the higher rates of nitrogen (N) fertilizers [ammonium nitrate (NH4NO3), Ca(NO3)(2), or urea]. Calcium chloride sprays increased yield of 'Anjou' pears if it was applied over many years.