• Unscorched foliage is a sign of a healthy apple tree.Apple-tree image by zalisa from Fotolia.com
  
  Leaf scorch impacts the health of an apple tree. Leaf margins look and feel dry and burnt. There is no one disease responsible for leaf scorch on apple trees. Often the causes are cultural and not fungal or bacterial. Identifying the cause helps you remedy the problem before the apple tree's health begins to decline.
  
  

Root Damage

• Scorch is often a result of root damage on newly planted apple trees. Time provides the only cure in this case, as the roots heal and the young tree recovers. Established trees may suffer root damage from nearby construction, burrowing rodents or from insects attacking the root systems. Leaf scorch is often the first indication that such damage is occurring. Scorched leaves drop prematurely from the tree when the root damage is severe, while minor damage usually heals itself by the following season.
  
  

Fireblight

• Fireblight causes major damage on apple trees. Caused by bacteria, the blight first causes leaf scorching that makes the foliage appear as though it was burned in a fire. Eventually the blight attacks young twigs, flowers and fruit as well as the leaves. Fireblight can be deadly to apple trees. It is most common during hot, humid weather. Removing infected branches and treating with a bacteriacide helps control the bacteria until the apple tree can recover on its own.
  
  

Drought Stress

• Many apple trees are affected by minimal leaf scorching each summer caused by drought stress. Mature trees usually suffer no long-term damage from short periods of drought. Regular irrigation, especially during the hottest part of the year, prevents leaf scorch and drought damage to the fruits. Applying a mulch over the soil beneath the tree also helps retain soil moisture, which prevents stress and scorch.
  
  

Insects

• Insect damage stresses apple trees, and often the foliage is the first area to show damage. Heavy infestations of boring and sucking insects are the most damaging. Their feeding inhibits nutrient and water uptake to the leaves, eventually causing them to scorch. Identify and treat the insect infesting the apple tree to eradicate the scorch.