Copper sulphate is a fungicide used to control bacterial and fungal diseases of fruit, vegetable, nut and field crops. Some of the diseases that are controlled by this fungicide include mildew, leaf spots, blights and apple scab.
 
It is used in combination with lime and water as a protective fungicide, referred to as Bordeaux mixture, for leaf application and seed treatment. It is also used as an algaecide, an herbicide in irrigation and municipal water treatment systems, and as a molluscicide, a material used to repel and kill slugs and snails.
 
It is generally used as insecticide in agriculture & in the wood industry.
 
The uses of copper sulphate are:
 As a Herbicide, Fungicide and Pesticide.
To control the amount of algae in ponds etc.
To test for proteins (used in the Biuret reagent).
To test blood for anaemia. Blood is put in copper sulphate solution, but containing sufficient Haemoglobin sinks.
To sometimes make deep blue-green fireworks.
As a hair dye (with other chemicals).
Processing of leather and textiles.
To make Copper Sulphate Crystals.