FUNGAL DISEASE OF APPLE

1. SUBMITTED TO,
Dr. Mrs. S. SIMON SUBMITTED BY,
NAVNEET
I.D. NO. – 15MSENT015
Subject:- Insect vectors of plant viruses and other pathogen

2. • Botanical name:- Malus domestica
• Family:- Rosaceae
• Native:- Central Asia
• Distribution:-Apple is distributed all over
the world. In India Jammu and Kashmir,
Himachal Pradesh, Arunachal Pradesh
Uttaranchal.

3.  The apple is a decidious tree, generally standing 1.8 to
4.6 m tall in cultivation and up to 12 m in the wild.
 As one of the most cultivated and consumed fruits in the
world, apples are continuously being praised as a "miracle
food".
 Apples are extremely rich in important antioxidants,
flavanoids, and dietary fiber. The phytonutrients and
antioxidants in apples may help reduce the risk of
developing cancer, hypertension, diabetes, and heart
disease. This article provides a nutritional profile of the
fruit and its possible health benefits.

4. Early Season Diseases of Apple
 Apple scab
 Cedar apple rust
 Powdery mildew
Late Season or “Summer” Diseases of Apple
 Sooty blotch
 Fly speck
 Black rot
 White rot
Other important Diseases of Apple
 Phytopthora crown and root rot
 Fire blight

5. Apple scab
Cedar apple rust
Powdery mildew
 These diseases develop in the orchard between
bud break and early to mid summer.
 Control measures for these diseases need to be
conducted during this period.

6. Symptoms:
On leaves:
 Velvety olive-green spots with unclear
margin appear on the leaves.
 Later, the lesions enlarge, and become
darker with more distinct margins.
 Heavily infected leaves become distorted
and drops early in the summer.
On fruit:
 Spots are similar to those found on leaves.
 Spots darken with age and become black
and “corky” or “scabby”.
 Scabs are only skin deep.
 Cracks often develop on these scabby
areas.

7. Disease Development:
 Caused by the fungus Venturia inaequalis.
 The fungus overwinters in the previous year's
diseased leaves that have fallen under the tree.
 In the April, May and June, the fungus produces
millions of spores in the old leaves on the ground.
These spores are shot into the air and carried by the
wind or splashing rain to young leaves, flower parts
and fruits.
 A free film of water on leaves and fruit is required for
the spores to germinate and infection to occur.
 Transmitted by Tarnished Plant Bug

9. Symptoms:
On upper side of the leaves:
› Pale yellow or orange spots appear during May
or June.
› Small black fungal fruiting bodies (pycnia) form
within the spots and may exude an orange
fluid.
On lower side of the leaves:
› During late spring and early summer,yellow
spots develop on the underside of the leaf.
› Within these spots a number of small, orange-
yellow tubular projections (aecia) appear.
Infected leaves may turn yellow and drop.
› Defoliation of rusted leaves is most common in
dry summers.

10. Symptoms:
On Fruit:
 Similar yellow-orange spots
appear, usually at or near the
calyx end.
 These spots are much larger than
the spots on leaves.
 The tube-like aecia may form on
the slightly raised fruit lesions.
 Infected fruits are often stunted
and misshapen, and may drop
early.

11. Disease development:
 Caused by the fungus Gymnosporangium
juniperivirginianae.
 The fungus overwinters as mycelium in
galls on juniper or cedar. Large yellow to
orange gelatinous sporehorns are formed
on the galls in the spring and spores
(teliospores) are produced.
 Each teliospore germinates and produces
four to eight sporidia or basidiospores.

12. Disease development:
 Sporidia are carried by wind to nearby apple leaves,
fruits, and twigs where they penetrate the cuticle and
lesions develop on the upper leaf surface and on
fruit.
 After 10 to 14 days, the orange to black pycnia
develop in the spots on the upper leaf surface.
 Transmited by black aphid.

13. Symptoms:
 Small, whitish patches of fungal growth appear
and quickly cover the entire leaf.
 Diseased leaves become narrow, crinkled,
stunted and brittle.
 Infected blossoms shrivel and produce no fruit.
 Fruit symptoms are not usually seen unless the
disease has built up to high levels on
susceptible cultivars. Diseased fruit have a fine
network type surface blemish called russetting.

14. Disease development:
 Caused by the fungus, Podosphaera leucotricha.
 The fungus overwinters as mycelium in terminal buds and
twig tips infected during the previous year.
 As buds break dormancy, the powdery mildew fungus
resumes growth and colonizes developing shoots causing
primary infections.
 The powdery white appearance on infected shoots consists
of many thousands of spores which are responsible for
spreading the fungus later in the growing season.
 Powdery mildew infections occur when the relative humidity
is greater than 90% and the temperature is between 50-77
degrees F.

15. Powdery mildew of apple is transmitted by
mites and black aphid of appple.

16.  Free water (wet conditions) is required for
most fungal pathogens to infect plants. Any
practice that promotes faster drying of fruit
and foliage is beneficial for disease control.
› Site selection
 Select a site with good air movement all-day
sun light, and good soil drainage.
 Do not plant trees in shaded areas.

17. › Canopy management
 Control timing and amount of nitrogen fertilizer
to prevent excessive growth.
 Prune out and destroy all dead or diseased
shoots and limbs while trees are dormant (mid-
March is usually a good time).
 Prune healthy growth to improve air movement
and sunlight penetration, to minimize shading
and decrease drying time of leaves and fruit
during the growing season.

18. › Sanitation
 These sanitation measures will reduce the number of
spores that can initiate these diseases.
› Fungicides
 On susceptible varieties, fungicides may be required
to obtain an acceptable level of disease control.
 Use of disease resistant apple varieties
› Early season varieties: Redfree, Prima, Jonafree, Sir
Prize
› Mid-season varieties: Novamac, Liberty, Freedom
› Late-season varieties: Enterprise, Goldrush
Other disease resistant varieties are available.

19. Sooty blotch
Fly speck
Black rot
White rot
 These diseases develop in the orchard from shortly
after petal fall through harvest; therefore, they are often
referred to as “summer diseases”.
 Control measures for these diseases need to be
conducted during this period.

20. Symptoms:
On fruit: Black Rot
 At first, a light brown spot form on the fruit.
 With time, the spots enlarge and
commonly develop a series of brown and
black concentric bands or rings.
 The rotted fruit finally turns black. The
decayed tissue remains firm to leathery,
and holds its original shape until the entire
fruit is rotted.
Rotted fruit shrivel into mummies and often remain attached to
the tree.
Black, pimple-like fruiting bodies (pycnidia) of the causal fungus
appear on the surface of rotted fruit.

21. Symptoms:
On leaves: Frogeye leaf spot
 Round to irregularly lobed spots develop a light
brown-to-gray center surrounded by one or
more dark-brown concentric rings and a purple
margin giving it a "frogeye" appearance.
 Black pycnidia may develop on the upper
surface in the centers of the older leaf spots.
On branches:
 Small, slightly sunken, reddish-brown areas
develop in the bark. These areas slowly
enlarge and darken to form cankers.
 Cankers may continue to expand a little each
year, and may extend down the limb for 3 feet
or more.

22. Disease development:
 caused by the fungus, Physalospora obtusa.
 The fungus overwinters in cankers, mummified fruits, and the bark of
dead wood.
 In the spring, the fungus produces spores on these previously infected
plant parts.
 The heaviest release of spores occurs around blossom time, but the
production of spores may continue during wet periods throughout the
summer.
 Leaf infection usually occurs during the petal-fall period.
 Fruit infection can occur as early as petal fall; however, symptoms are
usually not visible until mid to late-summer as the apple approaches
maturity.
 A film of free water on plant surface and temperatures of 75-80
degrees F are favorable for spore germination and host infection.

23. Transmitted by codling moth

24. Symptoms:
On fruit:
 At first, small, reddish-brown spots appear around
the lenticels.
 The spots enlarge and become slightly depressed.
On yellow-skinned varieties, these spots may be
bordered by one or more red "halo" rings.
 The tissue under the spots is soft and the rotted area
is egg shaped.
On branches:
 Small, circular spots or "blisters" appear on the twigs
in June and July.
 The spots enlarge, become somewhat sunken, and
fill with a watery fluid.
 Infected areas are slightly sunken and eventually
form dark colored cankers.

25. Disease development
 caused by the fungus Botryosphaeria dothidea.
 The fungus overwinters on living and dead cankered limbs and in
rotted fruits.
 In the spring, the fungus produces spores in these previously
infected plant parts.
 The spores are rain-splashed or blown to other parts of the tree
during rainy periods.
 Wounds or breaks in the epidermis are necessary for the fungus
to penetrate.
 Apple fruits may become infected fairly early in the season, but
fruit rot does not develop much until the fruit is almost mature.
 At temperatures above 75 degrees F, mature fruit may rot
completely within a few days after infection.

26. White rot disease is transmitted by beetles

27.  Free water (wet conditions) is required for these
fungal pathogens to infect plants. Any practice that
promotes faster drying of fruit and foliage is
beneficial for disease control.
› Site selection
 Select a site with good air movement all-day
sun light, and good soil drainage.
 Do not plant trees in shaded areas.

28. › Canopy management
 Control timing and amount of nitrogen fertilizer to
prevent excessive growth.
 Prune trees annually during the dormant season
(mid-March is usually a good time).
 Remove wild hosts
 Remove and destroy nearby wild or neglected apple
trees. Wild brambles (raspberry and blackberry)
serve as a reservoir for sooty blotch and fly speck
and should be removed.
› Sanitation – Black rot and White rot
 Prune out and destroy all dead wood, cankers, and
black rot mummies.

29. Reference:-
http://www.ag.ohio-state.edu/~plantdoc/extension.php
http://www.ohioline.ag.ohio-state.edu