Question
Dear Sir

I was wondering if you could give some advice on my tomato plants.
The leaves seem to be dieing off, the fruit has a brownish colour at the bottom of it and they seem to be splitting.
The tomatoes have not yet ripened, but are near.
Any advice on what and how to treat the problem would be most appreciated.  

Answer
Hi Daniel,

The symptoms you describe can be due to a deficiency in calcium.  Blossom End Rot is a common disorder when there is insufficient calcium in the soil.  Leaves can be affected also, and they may appear rolled and exhibit necrosis (dying), chlorosis (yellowing), and scorching of the margins or tips.  

Here is a link to see the symptoms on the fruit:

http://vegetablemdonline.ppath.cornell.edu/PhotoPages/Tomatoes/Tom_BlossRot/Tom_...

Here is another link to see the symptoms on the leaves.  This is a potato plant, but they are closely related to tomato.  

http://www.hbci.com/~wenonah/min-def/potato.htm


Adding calcium to the soil in the form of agricultural lime can be effective, but that is something to do for next year.  Application of calcium nitrate and calcium chloride solutions (sprays) will be more effective on growing plants.  There are products available at your local garden center that you can apply.  

To minimize the effects of calcium deficiency, avoid stress to the plant, e.g. don't let the plant get too dry or keep it too wet.  A balanced fertilizer (water-soluble)should be applied regularly.  There are specialized formulations for tomatoes, but they are really unnecessary.  If given a choice select a fertilizer with a higher phosphorous content, e.g. 10-30-10.

Splits and cracks in tomato fruits are usually due to excess water availability.  This often happens after an extended or intense rainy period.   

Good Luck and Good Gardening.