All you need to know about Blossom End Rot, dont let your plants dry out!
Here is all the information that you need about Blossom End
Rot on tomatoes. However before you try adding calcium etc to your soil it is
worth nothing that there is normally not a deficiency of calcium in the soil as
90% of the times I have had Blossom End Rot is in hot weather and I have let
the compost or soil dry out that bit too much. It happens easier if you are
growing in post of peat bags. When the Blossom End Rot appears it is usually a
few days after the soil has dried out, so although your soil might seem OK, it
might not have been a few days before.
Blossom-end rot (BER) is generally thought to be triggered
by a localized calcium deficiency in the blossom end of the fruit.It often occurs when dry soil conditions
reduce the amount of water movement into the plant, interrupting the movement
of calcium to the fruit, so it is not lack of calcium in the soil.Calcium is an important component of cell
development.Therefore BER is caused
primarily by dry soil conditions, not by a deficiency of calcium in the soil or
A small water-soaked or light brown area appears around the
blossom-end of the tomato when the fruit is green or just ripening.The lesion darkens and enlarges rapidly,
becoming sunken and black.It may affect
over half of the fruit.
Soil or foliar applied calcium has not been shown to be effective
in preventing BER.Foliar-applied
calcium is taken up and fixed in the leaves, and very little reaches the fruit.
Besides moisture, many other factors seem to influence BER
as well.In fact, there is now some
thought that low calcium levels in the fruit are not the trigger for
blossom-end rot at all.
The list of factors that could influence blossom-end rot:
and intense sunlight, especially following cooler, overcast weather;
ammonium-nitrogen levels in the soil,
such as dry conditions, that reduce fruit growth;
during periods of rapid fruit growth;
ratios in the fruit;
High nitrogen levels;
There is now speculation that stress-free, rapid growth
conditions create the susceptibility for blossom-end rot in fruit at a certain
stage of development.If conditions
suddenly turn stressful, reducing growth rates, blossom-end rot is thought
likely to develop.