tomatoe question

Bill Shoemaker wshoemak at
Fri Aug 11 09:51:32 EDT 2000

>Sounds like you have blossom end rot. (BER) Problem is caused by lack of
plant available
>calcium that can be aggravated by inconsistent watering. Some varieties are
>susceptible than others. The tissue at the tip, or blossom end is very weak
from the lack
>of calcium and is easily invaded by bacteria and fungi. Water soluable
calcium nitrate is
>about the quickest solution
>Joel @ Territorial Seed

    It's very important to emphasize that fertilizing with a calcium-based
fertilizer is not very effective in controlling blossom-end-rot. Plants have
more difficulty in moving calcium through the plant than any other mineral
nutrient. Even if your soil is extremely rich in calcium your tomatoes (and
peppers, watermelons cucumbers and other vegetable fruits) can develop BER.
The real key is a steady, constant supply of moisture, not too much and
especially not too little. Maintaining a high quality soil (friable, rich in
organic matter) helps because it holds so much moisture. But even more
importantly, don't just depend on rain and soil moisture. When fruit are
developing on the crop, adequate soil moisture must be maintained.

    Calcium nitrate is a useful fertilizer but it will not correct BER.
There have been many trials that have demonstrated this point. Many times a
farmer will apply it to a tomato crop and ignore the moisture situation.
When the new fruit coming along fail to develop BER the credit is given to
the calcium nitrate when a change in the soil moisture supply is the likely
reason for the solution. But growers love to solve problems so it's easy to
take credit.

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

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