Quince diseases A Lecture on ToT By Allah Dad Khan

2. Pear Diseases
A
Lecture To ToT trainees ( FFS)
By
Mr. Allah Dad Khan
Provincial Coordinator IPM KPK
MINFAL Pakistan

3. Powdery Mildew Podosphaera leucotricha
Symptoms
 Podosphaera
leucotricha is a
plant pathogen that
can cause powdery
mildew of apples and
pears.

4. Fire Blight
Fire blight Symptoms

Erwinia amylovora
 Symptoms
 Shoots and blossoms turning black and
shriveling; plant appears as if it has been
scorched by fire; watery exudate may be
present on infected areas
 Cause
 Bacterium
 Comments
 Disease emergence favors warm rainy days
during bloom; care should be taken to time
antibiotic application properly
 Management
 Cut out diseased wood; treat with Bordeaux
mixture or approved fixed copper materials for
organic production; streptomycin or copper
application to blossoms may be necessary to
prevent spread

5. Scab Venturia pirina
Symptoms
 Yellow or chlorotic spots on leaves;
dark olive green spots on leaves
and fruit; may be a velvety growth
on spots on undersides of leaves;
twisting of leaves; distorted
leaves; severely infected leaves
turn yellow and drop from tree
 Cause
 Fungus
 Comments
 Fungus overwinters on dead
foliage on ground; spores
dispersed by wind; high moisture
encourages fungal growth

6. Bitter Rot
Symptoms
 Glomerella
cingulata is a plant
pathogenic fungus th
at causes disease on
many different hosts
including quinceand a
pple bitter rot

7. Pear Stony Pit
Symptoms
 : Symptoms begin as early as
three weeks after petal fall, when
dark green spots form on the fruit.
Areas surrounding these spots
continue to grow while spots stop,
resulting in misshapen fruit with
pits (photo Pits often become
necrotic and the fruit beneath
becomes sclerotized; heavily pitted
fruit may become so gritty that it
is difficult to cut with a knife.
Pimpling and cracking of the bark,
stunting of the trees, and chlorotic
vein-banding or mottling have also
been reported.

8. Silver Leaf Chondrostereum purpureum
Symptoms
 Silver leaf is a fungal disease
of treescaused by the fungus
plant
pathogenChondrostereum
purpureum. It attacks most
species of the rose
familyRosaceae, particularly
the genus Prunus. The disease
is progressive and often fatal.
The common name is taken
from the progressive silvering
of leaves on affected
branches. It is spread by
airborne spores landing on
freshly exposed sapwood

9. Blue mold rot
Symptoms
 Penicillium (/ˌpɛnɪˈsɪlɪəm/
) is
agenus of ascomycetous fu
ngi of major importance in
the natural environment as
well as food and drug
production.
 Some members of the
genus produce penicillin, a
molecule that is used as
an antibiotic, which kills or
stops the growth of certain
kinds of bacteria inside the
body

10. Pseudomonas syringaeBlast
Symptoms

Water-soaked or black lesions on leaf
petioles;which rapidly expand along the leif
midrib; cankers on twigs and branches; twigs
may be girdles and die; leaves turning black
and dying; black lesions may be present on
fruit
 Cause
 Bacterium
 Comments
 Disease emergence favors cold, wet weather
 Management
 In areas where disease is severe, copper
fungicides should be applied in Fall and WInter


11. Crown and root rot Phytophthora spp.
Symptoms
 Leaves wilting but remain attached to
the tree; reduced growth; early
senescence; cankers at soil level, dark
discoloration of bark which is slimy
when wet
 Cause
 Oomycete
 Comments
 Disease emergence favors poorly
drained soil and standing water
 Management
 Practice good water management to
prevent emergence of disease; do not
over-water trees or allow water to
accumulate in soil; there is no
treatment for Phytophthora infection
once present; no apple varieties are
resistant to all strains of the pathogen

12. Spring pear cankerworm (Fall pear
cankerworms)
Paleacrita vernata Alsophila pometaria
Symptoms
 Leaves are skeletonized
to nothing but the
veins; young fruit have
scarred depressions
 Cause
 Insect
 Comment

13. Pear decline phytoplasma
Symptoms
 Poor shoot growth; dieback of
shoots; reddening and rolling
of upper leaves in canopy;
premature leaf drop; reduced
leaf and fruit size
 Cause
 Phytoplasma
 Comments
 Transmitted by pear psylla
 Management
 Plant trees which have been
grafted on tolerant rootstocks;
control pear psylla on trees

14. Armillaria root rot (Oak root fungus)
Armillaria mellea
Symptoms
 Small, discolored leaves which drop
early; death of branches; death of
plant; clusters of honey-colored
mushrooms may sprout at base of plant
 Cause
 Fungus
 Comments
 Fungus survives on dead roots in soil
 Management
 Armillaria root rot cannot be effectively
controlled once it has become
established in an orchard; diseased or
dead plants should be uprooted and
removed; planting resistant rootstocks
is the most effective method of
preventing the disease

15. Pythium
Symptoms
 Pythium is
a genus of parasiticoomyc
otes. Most species
are plantparasites,
but Pythium insidiosum is
an
important pathogen of ani
mals. They were formerly
classified as fungi; the
feet of the fungus
gnat are frequently a
vector for their
transmission