BLOSSOM END ROT
Nearly every year home owners become very concerned when
they begin noticing the bottoms of their tomatoes turning
dark. This is a condition called "Blossom-End Rot"
(BER). (NOTE: Conscientious horticulturists refrain from discussing
Blossom-End Rot for fear that careless secretaries might inadvertently
omit certain letters such as the "l" and "s"
from the term. This would create widespread panic among the
female population; the AIDS fear is enough for any society
without horticulturists conjuring up the possible epidemic
of Bosom-End Rot!) Blossom?end?rot is quite a common occurrence
on tomatoes but also is a problem on other crops such as peppers
and watermelons. Although it may occur anywhere on the fruit,
it generally occurs at the blossom end or bottom. It can occur
at almost anytime during the development of the fruit. It
generally begins with the appearance of small, irregular-shaped
water soaked areas near the base of the fruit which darkens
and eventually can become leathery in appearance. When severe
enough, it actually appears to wrinkle and can deteriorate
as the fruit matures. To see an actual image of this disorder,
http://images.google.com/ and enter “blossom-end rot
Why does blossom-end-rot occur? Researchers are not quite
sure of the exact cause but most agree it is associated with
a deficiency of calcium as well as excessive water loss. One
thing is certain, and that is that there are no pathogens
associated with its occurrence. Fungus or other types of disease
may infect the bottom of the fruit after the occurrence of
blossom-end-rot, but these are secondary in nature.
Blossom-end-rot is a "physiological" disorder
of tomato fruit. Conditions which favor its occurrence are
those which result in water stress of the plant. These could
be soils which are too wet, soils that are too dry, or drying
winds which increase water loss from the foliage. Whenever
these conditions occur, the plants will lose more water to
the atmosphere through its foliage than it can absorb through
its roots. This will result in water loss from the plant and
the fruit, resulting in a slight desiccation of the blossom-end
or the bottom of the tomato fruit. These cells die, resulting
in the appearance of the blackened area. This condition is
aggravated when growing containerized plants since it is difficult
to constantly maintain optimum soil moisture levels.
The visual symptoms associated with blossom-end -rot often
are the result of a condition which may have occurred several
days or even weeks prior to the symptoms. Therefore, when
homeowners begin to worry about the occurrence of blossom-end-rot,
the cause may have been several weeks prior to the conditions
causing the problem.
What can be done about blossom-end-rot? It's obvious that
anything which will maintain uniform soil moisture will help.
A garden located in a well drained soil will go for a long
way toward preventing "BER" that is associated with
soggy or too wet soil. A good mulching program will also help
as it reduces water loss from the soil and makes it more available
to the plant during dry periods. A uniform and consistent
watering program is also vitally important. Insuring a supply
of readily available calcium will help prevent this problem.
This is why a yearly application of gypsum (calcium sulfate)
is now recommended even in this area's highly calcareous soils.
One of the questions that always comes is whether or not
the affected fruit should be removed from the plant. There
are those who feel that the fruit exhibiting blossom-end-rot
should be left on the plant because if they are removed the
problem will appear on other fruit. Others feel the fruit
should be removed because the tissue can decay and serve as
a source of sever diseases later on. These fruit will require
nourishment from the plant to mature which could be utilized
to produce top quality tomatoes. But by the same token, these
fruits are still edible where the affected area is trimmed
away, provided no secondary rot of the fruit occurs.
What should the homeowner do? The consensus of opinion among
Texas horticulturists is that the fruit should be removed
to allow for the development of first-quality fruit rather
than mature a fruit effected with blossom-end-rot. Locate
the garden in a well drained area of the yard, use a good
mulching program and maintain sufficient and adequate soil
moisture for good growth.
The problem always seems worse than it really is because
the BER affected tomatoes are ALWAYS the first to ripen. Since
we are hungry for fresh, spring tomatoes, any blemish on the
first, precious fruit generates hysteria. In actuality, less
than 10 per cent of all fruit produced by an effected plant
will be damaged. BE CALM! Blossom-end-rot can be eliminated
by the removal of the effected fruit--suppose you had to deal