Relationship of fertilizers on soil ph and fruit disorders of apples and pears

Abstract

In nutrition experiments of fruit‐growing areas of central Washington state, ‘Delicious’ and ‘Golden Delicious’ apple (Malus domestica) orchards and ‘d'Anjou’ pear (Pyrus communis L.) orchards with the lowest soil pH values had a high incidence of fruit disorders and the lowest concentration of leaf calcium (Ca). In contrast, orchards with the highest soil pH values had the highest concentration of soil Ca (meq 100 g^‐1) and the lowest incidence offrait disorders (bitter pit for apples and alfalfa greening, black end and cork spot for pears). Apple orchards with the highest soil pH values also had ‘Delicious’ and ‘Golden Delicious’ apples containing the highest concentration of Ca, but Ca concentrations in ‘d'Anjou’ pears were not significantly different among the different soil pH groups.