Author: Esther McGinnis

Symptoms

• Bitter pit causes dark lesions on the apple skin and just under the skin’s surface.
• The lesions appear primarily in storage but may sometimes occur just before harvest.
• The lesions may be bitter tasting.
• ‘Cortland’ and ‘Honeycrisp’ are highly susceptible to bitter pit.

Figure 1.  Bitter pit lesions initially look like light-green bruises on the surface of the fruit (Esther McGinnis, NDSU) 

Figure 2. The lesions then become brown and slightly sunken (Esther McGinnis, NDSU)

Management and other important facts

• Bitter pit is caused by the leaves out-competing the fruit for available calcium.
• Avoid over-fertilizing because high levels of nitrogen and potassium may exacerbate the problem.
• Maintain good soil moisture with supplemental irrigation during dry periods and apply mulch.
• Calcium chloride sprays can be applied directly to the fruit but are not always effective.