Avoiding Apple Sunscald or Sunburn
Sunscald or sunburn in apples accounts for yellow or flushed areas on the fruit skin due to direct sun damage often following a period of cooler, cloudy weather.
In severe instances, the scald damage turns dark while the fruit is still on the tree, with the underlying tissue becoming spongy. It is also associated with poor calcium content in the fruit. A balanced crop nutrition can help avoid sunburns.
Crop Nutrition and Sunscald / Sunburn
Potassium
A higher concentration of potassium in apples reduces the incidence of sunburn/sunscald. However, potassium needs to be in balance with calcium, as these two nutrients compete with each other and can lead to poor calcium content in fruits, resulting in storage problems and other disorders related to calcium deficiency.
Calcium
By improving calcium content in the skin and pulp, cells are less liable to damage and subsequent breakdown, thereby avoiding sunscald damage in apples.
Related articles
Improving Apple Coloration
Color of the skin is a very appealing apple quality to consumers. Therefore, growers generally seek to improve fruit coloration. Crop nutrition can help to achieve the desired appearance.
Role of Nutrients by Apple Growth Stage
Here you find an overview of the role of nutrients by apple growth stages.
Minimizing Incidence of Apple Rots and Diseases
Many disease-causing pathogens (fungi, bacteria, viruses and nematodes) attack apple trees. These may damage the fruit directly, making it unattractive or inedible, but also weaken the apple tree by injuring or invading the leaves, trunk and branches....
