What's wrong with my plant? Give us your feedback

Crab Apple > Branch > Branch dieback

1 of 8
  • Image: Winter Injury 1
    Credit: T. McCamant, Northland Community and Technical College
  • Image: Winter Injury 2

    Credit: T. McCamant, Northland Community and Technical College

  • - CLICK PHOTOS TO ENLARGE -

green arrowWinter 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
  • More information on Winter Injury...
2 of 8
  • Image: Black Rot 1
    Credit: G. Sundin, Michigan State University, Michigan State University
  • Image: Black Rot 2

    Credit: M. Grabowski, University of Minnesota

  • - CLICK PHOTOS TO ENLARGE -

green arrowBlack Rot
Botryosphaeria obtusa

  • Leaves on girdled branches wilt, die and turn brown
  • Branch cankers can be sunken, reddish brown or rough looking or cracked bark; cankers may remain small or enlarge to become several feet long
  • 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 8
  • Image: Fire Blight 1
    Credit: G. Sundin, Michigan State University, Michigan State University
  • Image: Fire Blight 2

    Credit: G. Sundin, Michigan State University, Michigan State University

  • Image: Fire Blight 3

    Credit: University of Georgia Plant Pathology Archive, University of
    Georgia, Bugwood.org

  • - CLICK PHOTOS TO ENLARGE -

green arrowFire Blight
Erwinia amylovora

  • Infected leaves wilt, turn gray then dark brown
  • Young shoots bend over forming a "shepherd's crook"
  • Infected blossoms first turn gray, then black
  • Infected leaves & blossoms remain attached to the tree, often even in winter
  • Branch cankers have dark, sunken & cracked bark, sapwood is streaked reddish brown
  • 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...
4 of 8
  • Image: White Rot 1
    Credit: University of Georgia Plant Pathology Archive, University of Georgia, Bugwood.org
  • Image: White Rot 2

    Credit: University of Georgia Plant Pathology Archive, University of
    Georgia, Bugwood.org

  • - CLICK PHOTOS TO ENLARGE -

green arrowWhite Rot
Botryosphaeria dothidea

  • Leaves on girdled branches wilt, die and turn brown
  • Small blister like spots on branches exude, watery fluid
  • Branch infections grow to cracked, flakey, orange canker
  • 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
  • For management information see Black Rot...
5 of 8
  • Image: Drought Stress
    Credit: Robert L. Anderson, USDA Forest Service, Bugwood.org
  • - CLICK PHOTOS TO ENLARGE -

green arrowDrought Stress

  • Severe drought stress may cause dieback of individual branches
  • Uniform wilting or browning of leaves throughout the tree
  • Leaf margins and branch extremities usually brown and wilt first
6 of 8
  • Image: Dogwood Borer 1
    Credit: Minnesota Department of Agriculture
  • Image: Dogwood Borer 2

    Credit: Minnesota Department of Agriculture

  • Image: Dogwood Borer 3

    Credit: T. McCamant, Northland Community and Technical College

  • - CLICK PHOTOS TO ENLARGE -

green arrowDogwood Borer
Synanthedon scitula

  • Larvae feed in young trees often around lawn mower injuries, and in pruning scars of older trees
  • Feeding causes girdling and reduced sap flow
  • Brownish-red frass (excrement) is usually present at the feeding site
  • Adult is a black and yellow clear-wing moth, larvae are ½" long when mature, and white with a red-brown head
  • Adult emergence begins in mid-June, peaks in early July, and continues until August
  • More information on Dogwood Borer...
7 of 8
  • Image: Oystershell Scale 1
    Credit: E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, Bugwood.org
  • - CLICK PHOTOS TO ENLARGE -

green arrowOystershell Scale
Lepidosaphes ulmi

8 of 8
  • Image: Black Root Rot 1
    Credit: M. Grabowski, University of Minnesota
  • Image: Black Root Rot 2

    Credit: M. Grabowski, University of Minnesota

  • Image: Black Root Rot 3

    Credit: Division of Plant Industry Archive, Florida Department of
    Agriculture and Consumer Services, Bugwood.org

  • - CLICK PHOTOS TO ENLARGE -

green arrowBlack Root Rot
Xylaria mali and Xylaria polymorpha

  • Infected trees have slow growth, a thin canopy, dead branches, and small leaves
  • Black finger-like projections arise from the soil at the base of the tree
  • Infected roots are brittle and encrusted in black fungal growth
  • Infected trees produce many very small fruit

Don't see what you're looking for?