UC Master Gardeners, Santa Clara County, CA
University of California
UC Master Gardeners, Santa Clara County, CA

August Tips


 Tip title Bitter Pit on Apples
 Text description

Bitter pit is a physiological disorder that affects many varieties of apples. The condition develops after fruit has been picked. It is caused by low levels of calcium in fruit tissues, and fruit will develop small brown, sunken lesions that become dark and corky. Fruit that develops on vigorous, leafy, upright growing branches is more likely to be affected than fruit on spurs or horizontal wood. Highly susceptible cultivars include Red Delicious, Granny Smith, Golden Delicious, Jonathan and Gravenstein. The condition generally is caused by vigorous leaf growth, poor fruit set, and hot, dry growing conditions, which cause calcium to the diverted to the leaves. Spraying with a calcium nitrate solution (one-half teaspoon per gallon of water) just after bloom and again six weeks later may help.

The UC Postharvest Technology Center website has more information.

 Months applicable August
 Category 3. Pests and Diseases
Webmaster Email: webmaster-mgsantaclara@ucanr.edu