tomatoe question

Bill Shoemaker wshoemak at
Mon Aug 14 11:06:09 EDT 2000

>Must disagree with the statement that calcium nitrate, or calcium chloride,
will not help
>correct BER. While it is true that calcium is generally immobile

    It isn't immobile. It's merely less efficient in it's transport within
the plant than other mineral nutrients.

>within the plant there is
>no question that calcium can be absorbed by the fruit tissue and can be
recorded as an
>increase in ppm of calcium in the tissues at the blossom end of the fruit.
While the
>calcium needs to be applied very soon after blossom set and the solution
has to be applied
>in such a manner to saturate the blossom and tissues of the developing
fruits, we have
>demonstrated the benefit of such applications for several years. We have
>parthenocarpic male lines that are particularly susceptible to BER and
conducted detailed
>work on this problem for several years.

    While your experiences may have been positive, many efforts have been
made by researchers over the years to demonstrate the same thing in
production tomatoes. In general their conclusion is that calcium nitrate or
other forms of calcium applied as a foliar spray are less reliable than
proper water management in preventing BER and are often unreliable. The
bottom line is that to manage BER in fruiting vegetable crops the grower
will be most successful by managing the crop's need for water. There is
certainly no harm in applying calcium nitrate if done properly but it should
be a method of last resort in grower operations.

>Joel @ Territorial

Bill Shoemaker
Sr Research Specialist, Food Crops
Univ of Illinois - St Charles Hort Research Center

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