APPLE

• ALTERNARIA LEAF BLOTCH (Get the facts on biology, monitoring, and management)
  • Symptoms on leaves
  • Symptoms on Red Delicious fruit
  • Progression of symptoms across leaves
• ALTERNARIA ROT ON NITTANY
  • Symptoms on fruit
• APPLE SCAB (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Lesion on leaf in late spring
  • Lesion on leaf in mid-summer
  • Lesions on underside of leaf in mid-summer
  • Lesion on fruit pedicel shortly after petal fall
  • Lesion on fruit in late spring
  • Lesions on fruit in mid-summer
  • Lesion on fruit (showing cracks) in late summer
  • Lesions on fruit resulting from late summer infections (pinpoint scab)
  • Ascospores of Venturia inaequalis
  • Conidium of Venturia inaequalis
  • Disease cycle
  • Table of apple cultivar susceptibility to Venturia inaequalis
  • Table of susceptibility of scab-resistant cultivars to other diseases
• APPLE MOSAIC VIRUS (Get the facts on biology, monitoring, and management)
  • Leaf symptoms
• APPLE UNION NECROSIS (Get the facts on biology, monitoring, and management)
  • Discoloration at rootstock/scion union
  • Tree can break at graft union
  • Line of dead tissue between Delicious scion and MM.106 rootstock
• BITTER ROT (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Small lesions in early to mid-summer
  • Sporulating lesion in mid-summer
  • "V"-shaped rot pattern in flesh
  • Table of apple cultivar susceptibility to Colletotrichum spp.
• BLISTER SPOT (Get the facts on biology, monitoring, and management)
  • Symptoms on Mutsu fruit
  • Leaf infection
• BLACK ROT (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Frog eye leafspot
  • Rot lesion on fruit showing concentric zonation pattern
  • Limb dieback
  • Rough bark due to black rot
  • Black rot canker on trunk
  • Black rot canker on branch
  • Pycnidia on pruned material
  • Pycnidia on infected fruit
  • Apple mummy next to developing fruit
• BLACK POX (Get the facts on biology, monitoring, and management)
  • Fruit symptoms
• BLUE MOLD (Fruit Disease Focus article on biology and management)
  • Infected fruit in storage
  • Lenticel infection
• BROOKS SPOT (Get the facts on biology, monitoring, and management)
  • Fruit infection in mid-summer
  • Fruit infection in late summer
• CEDAR-APPLE RUST (Get the facts on biology, monitoring, and management)
  • Overwintering globose-shaped gall on Eastern red cedar
  • Exposed telia on gall, source of spores that infect apple
  • Leaf lesions in late spring
  • Close-up of rust pycnia on leaf lesions in late spring
  • Fruit infection in late spring
  • Fruit infection in late summer
  • Close-up of rust aecia on underside of leaf in mid summer
  • Closer view of rust aecia on underside of leaf lesions mid summer, showing recurved peridial cells and aeciospores that infect cedar
  • Disease cycle
  • Table of apple cultivar susceptibility to Gymnosporangium juniperi-virginianae
• FIRE BLIGHT (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Overwintering canker
  • First symptoms of infection (ooze) on blossom after petal fall
  • Blossom infection apparent after bloom (blossom blight)
  • Shoot infection in mid-summer (shoot blight)
  • Shoot infection from adjacent canker (canker blight)
  • Rootstock canker (rootstock blight)
  • Severe infection following hail (trauma blight)
  • Streptomycin injury to leaves
  • Disease cycle
  • Table of apple cultivar susceptibility to Erwinia amylovora
  • Table of apple rootstock susceptibility to Erwinia amylovora
• FLY SPECK (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Symptoms on fruit
• GOLDEN DELICIOUS NECROTIC LEAF BLOTCH (Get the facts on biology, monitoring, and management)
  • General appearance of trees
  • Close-up of foliar symptoms
• HAIL INJURY
  • Fruit
  • Bark
• NECTRIA TWIG BLIGHT (Get the facts on biology, monitoring, and management)
  • Dieback of Rome, symptoms similar to fire blight
  • General appearance of diseased shoot
  • Closer view of Nectria fruiting bodies and orange discoloration at last year's fruit node
• NECTRIA CANKER (Get the facts on biology, monitoring, and management)
  • Perennial canker on apple branch
  • Large cankers on Red Delicious trunk
• PHYTOPHTHORA ROOT, CROWN, AND COLLAR ROT (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Decline of trees in a poorly drained area
  • Tree with poor growth and sparse, off-color foliage
  • Tree showing wilt and collapse
  • Tree exhibiting purple leaf discoloration in autumn
  • Inner bark of affected rootstock
  • Inner bark of affected roots with knife at soil line
  • Sporangia of P. cambivora
  • Inner bark of affected rootstock
  • Disease cycle
  • Table of apple rootstock susceptibility to Phytophthora spp.
• POWDERY MILDEW (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Mildew on dormant shoots, top healthy
  • Healthy shoot on left, primary shoot infection on right
  • Close-up of leaf from primary infection
  • Infected blossom
  • Secondary infection (caused by conidia from primary infection)
  • Russet from fruit infection at bloom
  • Disease cycle
  • Table of apple cultivar susceptibility to Podosphaera leucotricha
• QUINCE RUST (Get the facts on biology, monitoring, and management)
  • Photos from the 2000 quince rust epidemic
  • Overwintering fusiform-shaped gall with exposed telia on Eastern red cedar
  • Fruit infection
  • Sporulation on fruit
  • Sporulation on red cedar tree trunk
  • Table of apple cultivar susceptibility to Gymnosporangium clavipes
• SOOTY BLOTCH (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Symptoms on fruit
• SOUTHERN BLIGHT (Get the facts on biology, monitoring and management)
  • Immature sclerotia on bark surface of rootstock
• THREAD BLIGHT (Get the facts on biology, monitoring, and management)
  • Leaf symptoms
  • Leaf symptoms
  • Tan mycelial "threads" and sclerotia on twig surface
  • Closer view of above
• WHITE ROT (Get the facts on biology, monitoring, and management) (Fruit Disease Focus article)
  • Rot lesion showing water-soaked appearance
  • Pycnidia oozing spores on surface of twig
  • White rot canker
  • Apple mummy next to developing fruit
• WOOD ROTS (Get the facts on biology, monitoring, and management)
  • General appearance of tree with wood rot infection
  • Limb breakage due to wood rot infection
  • Trunk infection with fungus fruiting bodies
  • Trunk infection without fungus fruiting bodies
• X-SPOT (Get the fact on biology, monitoring, and management)
  • Fruit symptoms

The Pear, Peach and Nectarine, Cherry, and Plum Index is on its own page now.

If you surfed here without going through our Home Page, you're missing a lot of neat stuff. Go to the WVU - Kearneysville Tree Fruit Research and Education Center Home Page.

Fruit Tree Books

Photographs and text have been reprinted with permission from the Mid-Atlantic Orchard Monitoring Guide, published by NRAES, 152 Riley-Robb Hall, Ithaca, New York 14853-5701. (607) 255-7654. See the list of plant pathologists who contributed to the Guide.

Additional photos, disease cycles, and text have been reprinted with permission from Diseases of Tree Fruits in the East, NCR-45, by Alan L. Jones and Turner B. Sutton. This publication is available for $10 from Michigan State University, Bulletin Office, 10-B Agriculture Hall, East Lansing, MI, 48824-1039. (517) 355-0240.

Web Site Author: Alan R. Biggs
Copyright ©1996-2009.