Bitter pit in Cox's Orange apples

Abstract Calcium nitrate and calcium chloride tree sprays. at different concentrations are compared. Calcium chloride, with about twice the calcium content of the nitrate, gave as good control of bitter pit at half the concentration of the nitrate, which relates the effectiveness of these materials to their calcium content. Colour development on apples was better with calcium chloride than with the nitrate. The slow. movement of calcium through apple flesh is demonstrated. When inadequate calcium sprays are used,- bitter pit may develop internally without showing its: presence on the apple surface.