Peach physiological disorders A Lecture By Allah Dad Khan To FFS Trainee

2. Nectarine Physiological Disorders
A
Lecture To ToT trainees ( FFS)
By
Mr. Allah DadKhan
Provincial Coordinator IPM KPK
MINFAL Pakistan

4. Chilling Injury

5. Chilling injury (CI)
• Chilling injury is the main limiting factor in the storage and shipping
of some stone fruits. The disorder is characterized by the
appearance of flesh browning, lack of juiciness due to wooliness,
blackening of the pit cavity, flesh translucency, red pigment
accumulation (bleeding), and loss of flavour. CI symptoms normally
appear after removing the fruit from cold storage and keeping it at
room temperature.
• Peach and nectarine cultivars vary greatly in their susceptibility to
CI. In general, early season cultivars are less susceptible and late-
season cultivars are more susceptible.
• The ideal way to eliminate this problem is to breed resistant
cultivars. In the mean time, temperature management is the best
tool commercially available to delay the onset of CI. Storage below
0°C (32°F) but above the freezing point is beneficial to delay CI
symptoms and extend market life.

6. Skin Discoloration, Inking, Staining,
Black Staining
• Symptoms
Inking symptoms appear as discolored brown and black spots or
stripes but are restricted to the skin.
• Physiology
Abrasion damage in combination with heavy metal contamination
are requirements for inking development. The damaged skin cells,
where the anthocyanin/phenolic pigments are located, collapse and
their contents reacts with heavy metals turning their color dark
brown/black. Iron, copper and aluminum (heavy metals) are the
most deleterious contaminants. Only 5-10 ppm iron is enough to
induce inking at the physiological fruit pH. This contamination can
occur within 15-20 days before harvest, during harvesting or
packing operations. Foliar nutrient, fungicide and insecticide
preharvest sprays which contain heavy metals in combination with
abrasion damage have the capacity to induce inking on peach and
nectarine fruit when sprayed close to harvest.

7. Internal browning, dry fruit, mealiness,
woolliness
• Symptoms
Flesh browning, flesh mealiness, black pit cavity,
flesh translucency, red pigment accumulation
(bleeding), and low flavor.
• Causes
These symptoms normally appear after placing
fruit at room temperature, while some ripening is
occurring, following cold storage. For this reason,
this problem is usually experienced by the
consumer, not the grower and/or packer.

8. Hail Damage

9. Heat Damage