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Ministry of Agriculture, Food and Rural Affairs

Calcium (pear cork spot)

Calcium is a vital component in cell walls and is involved in the movement of sugars and starches within the plant.


  • Indentations in the skin towards the calyx end
  • Affected areas are usually more yellow than rest of the surface
  • Brown spots on the skin, tissue beneath the pits is grayish-brown, dry and corky
  • Little resistance to knife, although fruits may be gritty
  • When fruits are peeled or cut, large masses of brown or grayish necrotic tissues are seen to underlie the spots
  • Often develops in storage, especially on Anjou
  • Certain trees have a higher percentage of cork spot each year than others
  • The amount of cork spot varies widely from year to year

Often Confused With 
Stony pit –stony areas difficult to cut through with a knife; smaller areas affected

Boron deficiency – discoloured areas are smaller

Tarnished plant bug injury – Longitudinal sections cut through the depressions or dimples show that tarnished plant bug feeding causes a narrow tube extending to the core (but not into the core)

Brown maromated stink bug- puncture area from late season feeding which can result in dimpling or sunken regions on the skin surface and white to brown pithy areas internally

The cause of cork spot of pear is unknown. Heavy dormant pruning increases the percentage of fruits showing cork. Cork spot is thought to be initiated during periods of high transpiration in trees whose root systems are inadequate to supply moisture during the critical period. Because cork spot does not always show external symptoms, it is advisable not to harvest and ship fruits from trees that have affected fruit.

Scouting Notes
Cork spot appears on fruit close to harvest. Anjou is very susceptible to cork spot and this condition is prevalent in seasons when hot, dry weather preceeds picking.

Though rare, deficiency may occur on coarse sandy loam soils with pH of 6.0-7.5.

Fruit which is low in calcium is more susceptible to a range of breakdown conditions in storage. Calcium deficient fruit are also more susceptible to sunburn.

Management Notes
Ensure good soil management practices to promote good root growth to improve water & nutrient uptake. 

Timely irrigation will help keep calcium moving into the tree.

Do not apply excessive amounts of potassium to soil as it competes with calcium and induces deficiencies.

Calcium sprays must contact the fruit for uptake to be effective; therefore water volumes capable of wetting the entire tree are required. However, calcium can cause foliar burning. Some formulations of calcium chloride (CaCl2) result in poor fruit finish if applied too close to harvest.

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