What is the difference between cork spot and bitter pit?

Cork spot and bitter pit are both physiological disorders of apples caused by low levels of calcium.  Visually, cork spots develop anywhere on the fruit, will be relatively small in number per fruit, are sunken and somewhat diffuse spots about 1/2 inch in diameter.  Beneath the spot will be a corky area extending into the flesh of the apple.  Bitter pit, on the other hand, develop only on the half of the apple opposite the stem, are smaller and a …

Why do some apples shrivel in storage and how can it be prevented?

Some apple cultivars shrivel during cold storage which is cultivar dependent.  One of the most common cultivars that this is a problem with is golden or yellow delicious due to a thinner layer of natural wax on the apple surface called the cuticle.  This natural wax is what causes apple to shine when rubbed on a cloth (“buffing”).   Although the apples are edible after shriveling, with pretty good flavor, it can be easily prevented.  Placing the apples in a plastic …

Can kaolin clay sprays reduce insect damage to apple fruit?

Yes. Kaolin clay (formulated commercially as Surround WP®) has been shown to be effective against several orchard pests, including apple maggot, white apple leafhopper, and pear psylla. It generally gives at least fair control of plum curculio and several species of fruit pest caterpillars (codling moth, oriental fruit moth, tufted apple bud moth, lesser appleworm). However, university trials also show that heavy use is harmful to beneficial species, and can lead to a flare up of European red mites or …

What is apple cork spot and can it be prevented with calcium sprays?

Apple cork spot is a physiological disorder that can affect apple quality and reduce visual appeal. Cork spot generally appears in the outer portion of the fruit flesh as small green dimples or depressions. This disorder may begin developing in June and continue throughout the initial stages of growth and enlargement. The green spots eventually enlarge to corky, discolored areas 1/4 to 1/2 inch into the flesh of the apple. The corky spots may occur anywhere on the fruit flesh.…