Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension
www.extension.umn.edu
612-624-1222

Extension > Garden > Diagnose a problem > What's wrong with my plant? > Fruit > Apple > Discolored, cracked or sunken area of branch

Print Icon Email Icon Share Icon

Apples > Branch > Discolored, cracked or sunken area of branch

1 of 5
  • Image: Fire Blight 1
  • Image: Fire Blight 2
  • Image: Fire Blight 3

Fire Blight
Erwinia amylovora

  • Branch cankers have dark, sunken & cracked bark, sapwood is streaked reddish brown
  • Young shoots bend over forming a 'shepherd's crook'
  • Infected leaves wilt, turn gray then dark brown
  • Infected blossoms first turn gray, then black
  • Infected leaves & blossoms remain attached to the tree, often even in winter
  • Infected fruit are shriveled and discolored
  • Drops of sticky honey colored liquid can be seen on infected plant parts in warm wet weather
  • More information on Fire Blight...
2 of 5
  • Image: Black Rot 1
  • Image: Black Rot 2
  • Image: Black Rot 3

Black Rot
Botryosphaeria obtusa

  • Branch cankers can be sunken, reddish brown or rough looking or cracked bark; cankers may remain small or enlarge to become several feet long
  • Leaves on girdled branches wilt, die and turn brown
  • Round leaf spots with a purple border & tan center
  • Large brown spots with brown rings form on fruit
  • Fruit is rotted but remains firm
  • Fruit may become mummified and remain on tree
  • Common on stressed trees & trees infected with fire blight
  • More information on Black Rot...
3 of 5
  • Image: White Rot 1
  • Image: White Rot 2
  • Image: White Rot 3

White Rot
Botryosphaeria dothidea

  • Branch infections grow to cracked, flakey, orange canker
  • Leaves on girdled branches wilt, die and turn brown
  • Sunken brown spots on fruit, can grow to rot part or all of fruit
  • Fruit rot is soft, watery and extends to the core of the apple
  • Small blister like spots on branches exude, watery fluid
  • For management information see Black Rot...
4 of 5
  • Image: Winter Injury 1
  • Image: Winter Injury 2

Winter Injury

  • Injured branches leaf out and then die, or don’t leaf out at all
  • Injured shoots and branches die quickly after warm weather arrives
  • Common after very cold winters with little snow cover
  • Dark streaking can be seen in the sapwood of injured branches
5 of 5
  • Image: Sunscald 1
  • Image: Sunscald 2

Sunscald

  • Vertical Cracks appear primarily on the south and southwest side of branch or trunk
  • Occurs during winter, often noticed early spring
  • More information on Sunscald...

Don't see what you're looking for?

  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy