| Tuber
External Growth Defects: SWOLLEN LENTICELS
Lenticels
are pores in the skin of tubers; botanically, they are stomates.
They are involved in gas exchange of oxygen and carbon dioxide during
respiration and photosynthesis. Besides giving an unmarketable appearance
to the tuber, the major problem is that an entrance to pathogenic
organisms, bacterial
soft rot,
pink
rot
and leak,
is created.
Development
and Appearance
Swollen
or enlarged lenticels (water spot, water scab) develop when tissue
below the lenticel swell and burst through the protective covering
of the lenticel. This forms a corky mass around the lenticel. The
disorder is somewhat reversible if the wet period is short.
Causation
This
disorder is caused by exposure of the tuber to very wet conditions
in the field or in storage. The swelling seems to be related to
oxygen deprivation by the watery film covering the lenticel.
Susceptibility
All
varieties are susceptible.
Cultural
Practices
Avoid
over-watering. Avoid harvesting low, swampy spots in the field.
Pick fields with good drainage. Avoid condensation in storage. Keep
storage well ventilated.
Summary:
External Disorders |
