Apple physiological disorders A Lecture By Allah Dad Khan To FFS Trainees

2. Apple Fruit Physiological Disorders
A
Lecture To ToT trainees ( FFS)
By
Mr. Allah Dad Khan
Provincial Coordinator IPM KPK
MINFAL Pakistan

5. SYMPTOMS
BITTER PIT. APPLE, GRANNY
SMITH

Small brown lesions of 2-10 mm in
diameter (depending on the cultivar)
develop in the flesh of the fruit. The
tissue below the skin becomes dark
and corky. At harvest or after a
period of cold storage the skin
develops depressed spots on the
surface. These most often start to
appear as water soaked spots on the
skin near the calyx. These spots
generally turn darker and become
more sunken than the surrounding
skin and are fully developed after
one to two months in storage.

6. SYMPTOMS
SUNBURN. APPLE, GRANNY SMITH
 Initial symptoms are white, tan or
yellowed patches found on the sun
exposed side of the fruit. With severe skin
damage, injured areas can turn dark
brown on the tree. White, tan or yellow
patches often turn brown within a few
weeks in cold storage (sometimes called
sunburn scald but not controlled by
antioxidants, such as diphenylamine, as is
storage scald). During unusually hot
weather following cool or moderate
conditions, and especially when
accompanied by water stress, injury to the
skin and flesh can occur. Injured cortex
tissue is brown and firm and may become
spongy and sunken. Fruit exposed to the
sun after removal from the tree, either on
the orchard floor or in field bins, can
develop severe sunburn.

7. SYMPTOMS
INTERNAL BROWNING. APPLE,
GRANNY SMITH

Brown discoloration in the flesh, firm
but moist, usually originating in or
near the core. Brown areas have
well defined margins and may
include dry cavities resulting from
desiccation. Symptoms can range
from a small spot of brown flesh to
nearly the entire flesh being affected
in severe cases. When the entire
apple is affected, a margin of
healthy, white flesh usually remains
just below the skin. Symptoms
develop early in storage and may
increase in severity with extended
storage time.

8. SYMPTOMS
SUPERFICIAL SCALD APPEARS AS BROWN
ROUGH PATCHES ON THIS GRANNY SMITH
APPLE
 Superficial scald is a very common
postharvest disorder. The appearance
and severity depends on the
susceptibility of the variety with
Granny Smith and Red Delicious being
among the worst affected. The skin of
the affected fruit turns brown in
patches, especially on the shaded side,
and may become rough. Only the
surface of the fruit is affected, with the
flesh remaining firm and of eating
quality. The margins between normal
and affected skin are diffuse. Browning
develops rapidly once the fruit is
moved from cold storage to room
temperature. (Compare to Senescent
scald.)

9. SYMPTOMS
GOLDEN DELICIOUS FRUIT SHOWING
SENESCENT SCALD AFTER COLD
STORAGE.
 Senescent scald appears as
brown patches on the skin that
may become sunken and rough
with distinct margins, often
ribbonlike. Unlike superficial
scald, senescent scald usually
appears on the sun-exposed side
of the fruit and on late harvested
fruit. Golden Delicious and late-
harvested or over-stored fruit may
be susceptible to senescent scald.
Also unlike superficial scald, the
interior of the fruit may have
brown flesh and have internal
breakdown.

10. SYMPTOMS
THE PINK GRADUALLY TURNS
BROWN
Core flush, a form of senescent
breakdown is common in Granny
Smith, Braeburn, and other apple
varieties. The core area turns
pink, then brown. The
discoloration starts near the core
and extends with wedges of
brownish tissue outward. The
discoloration may circle the core
partially or completely. The
affected tissue is moist and softer
than unaffected tissue. In severe
cases, it may extend just below
the skin. There is no exterior
symptom.

11. SYMPTOMS
 Overmature and large fruit are
highly susceptible to Internal
Breakdown. Internal breakdown is
characterized by flesh browning
and breakdown. Internal
symptoms may be restricted to
one side of the fruit, or involve the
entire fruit. Often there is a 1/4th
inch ring of healthy flesh
surrounding the affected tissue.
The sun-exposed side or the calyx
end is more often affected, with
the rest of the fruit normal. The
skin of affected fruits may be
normal, or dull and dark, and in
later stages of the disorder, it
sometimes becomes cracked

12. SYMPTOMS
SLICED BRAEBURN APPLES SHOW THE
PROGRESSION OF SEVERITY OF BBD
 The apple variety Braeburn is
susceptible to an internal
disorder called Braeburn
Browning Disorder (BBD). At
harvest, this disorder has the
appearance of light to dark
brown areas similar in nature
to watercore, but occurring
without pattern anywhere in
the flesh. Symptoms of BBD
developing in storage include
tissue browning resembling
the internal cavities caused by
CO2 injury. However, BBD is
thought to be related to late
harvest

13. SYMPTOMS
A GRANNY SMITH APPLE SHOWING THE CLEAR SKIN
BLOTCHES ON THE SLICE, EXPOSING THE WATER-
SOAKED FLESH BENEATH.
 Watercore appears as water-
soaked areas of the flesh first
associated with vascular bundles.
In severe cases, the affected
tissue may spread, covering large
areas of the flesh. In these
instances, watercore is externally
visible by the appearance of
translucent skin blotches on
lighter pigmented apples, or as
very dark patches on darker fruit.
In mild cases, watercore will
disappear (sugar reabsorbed)
early on during cold storage.
However, if severe enough,
watercore may develop into
internal breakdown (watercore
breakdown).