Copper fungicides Chemicals for Disease Control

Bordeaux and Burgundy mixtures are the dispersible forms of cuprous oxide and basic carbonates are among the important copper fungicides.

1. Bordeaux mixture: Bordeaux mixture (5: 5 : 50) is prepared as

Copper sulphate (Blue stone)             -5lb (2.26 kg)

Stone or hydrated lime                       -5 lb (2.26 kg)

Water                                                  -50 gallons

It is specific against downy mildew, late blight of potato, coffee rust, various leaf spots diseases, blights, anthracnoses etc.

2. Burgundy mixture: Burgundy mixture is also known as "Soda bordeaux" It is prepared as.

Copper sulphate                      -10 lb (4.5 kg)

Sodium carbonate      -12.21b (5.6 kg)

Water                          -50 gallons.

3. Chestnut compound: Chestnut compound contains two parts of copper sulphate and 11 parts of ammonium carbonate. The two substances are well powdered and thoroughly mixed and the dry mixture stored in an airtight receptacle for 24 hours before being used. It is used against damping -off disease.

4. Chaubattia paste: Chaubattia paste is prepared by mixing copper carbonate -800 g, red lead -800 g and raw linseed oil or lanolin -1littre.This paste was developed as a wound dressing fungicide to be applied to pruned parts of pears, apples and peaches for the control of disease, such as stem black, stem-brown, pink disease, stem canker of apples and pears, and collar rot of apples, peaches, apricots and plums.