What causes mis-shaped apple fruit?

Apples September 20, 2011 Print Friendly and PDF

Fruit shape is affected by many factors.  Mis-shapen fruit can result from insect or disease damage.  Tarnished plant bug and plum curculio attack very young fruit.  When that fruit matures, it often develops abnormally. 

Probably, one of the most common causes of mis-shapen fruit is the development of seeds within the fruit.  If seed development is dispersed around the core of the apple, usually the fruit will develop well and symmetrically.  If the seeds develop only on one side of the core, then that side will generally outgrow the side with fewer seeds.  This differential in growth results from seed-control of the hormone balance in the associated sides of the apples.  The lack of seeds within a fruit and the asymmetrical distribution of those seeds often occurs from inadequate pollination of the flowers.

Connect with us

  • Facebook


This is where you can find research-based information from America's land-grant universities enabled by eXtension.org



Apple Rootstocks

  • All about understanding and choosing the right rootstock

Apple Cultivars

  • Characteristics, descriptions, and how to choose the best to grow and eat

Establishing an Apple Orchard

  • Buying and planting trees

Managing Apple Trees and Orchards

  • Insects, diseases, wildlife and other challenges

Propagating Apple Rootstocks and Trees

  • Grafting, budding, tissue culture, and all about how rootstocks are developed

Regional Resources

  • Links to apple information specific to your area


This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.