The fungicide Copper Sulphate is used in organic farming thanks to its disinfectant action (eliminates micro-organisms), as it prevents and cures the development of a certain group of fungi that attack plants and can cause their death or loss of the harvest.
Fungi on which Copper Sulphate acts as fungicide
As a fungicide it acts on the fungi that cause:
Grey mould (Botrytis cinerea): It is manifested by the formation of a brown to grey cottony mass and the rotting of flowers, fruits or tender tissues. This fungus occurs on: strawberry, broccoli, vanilla, rose, etc.
Chupadera (Rhizoctonia spp.): it is manifested by damage or injury to the base of the stem (neck of the plant) when the plant is in its tender stage (first weeks of life), which causes the stem to break and the plant to die. It occurs in beans, chilli, spinach, beetroot, chard, etc.
How Copper Sulphate is applied to plants
Applying copper sulphate to plants is very simple, you will only need the following materials, the only one you may not have at home being copper sulphate:
- 1 litre of water
- 10 grams of copper sulphate.
- One spoon
- 1 Sprinkler
The proportion to be used is 10 grams of copper sulphate per litre of water. Mix both elements together and stir until the copper sulphate is completely dissolved. The water will have a blue colour, typical of the Copper Sulphate.
Recommendations for application
Copper sulphate should be applied by dispersing very fine droplets with a sprinkler (manual or automatic). It should be applied both on the upper and lower part of the leaves. In growing crops it is advisable to make two applications a week in periods of low temperatures and high humidity (winter), as it is under these conditions that the conditions are favourable for the development of the fungi mentioned above.
Application in lettuce plants
There are no toxicity problems on plants, i.e. it does not cause wilting or death of the crop unless the recommended dosage is exceeded or ambient temperatures are high.
Copper sulphate is sometimes used within the Broth Bordeles for use as a fungicide.