Low calcium concentrations produce bitter pit shown by depressed areas on apple surface and small, brown corky areas within flesh.
Made worse by
Acidic soils. Sandy or light soils (leaching). Acid peat soils. Soils rich in sodium. Soils rich in aluminium. Drought conditions. Fruit high in nitrogen or potassium. Large fruit.
Reduces Bitter Pit and other related disorders. Increases fruit size. Gives better fruit colour. Increases fruit firmness. Reduces storage disorders.
Calcium deficiency May be confused with boron deficiency. But boron deficiency causes symptoms in early state of fruit development, while calcium deficiency gives symptoms a few weeks before harvesting or in store.