DISEASE
 
   NAME
     Blossom-end Rot, Tomatoes
     Calcium Deficiency

Description
This non pathogenic disease results from calcium deficiency. 

Symptoms
This deficiency only affects the blossom end of the fruit causing a spongy water soaked area  This area dries out, becoming sunken and leathery turning black and covering up to half of the fruit. A secondary fungus may develop on the affected area in time. 

Favoured Conditions
There are several elements that attribute to this disease. Calcium deficiency occurs when the soil is dry or when other nutrients are abundant (over fertilising), suppressing the uptake. Erratic watering, ie dry to wet and then dry again or hot windy conditions decreases calcium uptake. When the plant has vigorous vegetative growth calcium is deprived from the fruit encouraging the disease.  

Affected Plants
The fruit of tomatoes and capsicum may be attacked at any time during development.

Non-chemical Control
Preventive measures include, soil preparation with adequate lime or superphosphate to supply calcium to the developing fruit. Apply calcium nitrate at a rate of 400g/100L of water fortnightly and supply water thoroughly during hot weather.  Cultivate and provide adequate drainage to the soil to prevent waterlogging, but maintain a constant supply of moisture to the roots. Mulch the soil and avoid planting in areas that are unprotected from hot dry winds or plant windbreaks. 
The fruit requires a steady supply of calcium during development.

Chemical Control
Not applicable