Bordeaux Mixture, basically a mixture of Copper Sulphate and hydrated lime which gets its name from years of use in the French Vineyards and as the mixture contains only 'natural ingredients', it may be considered ORGANIC (Organometallics).

  History of fungicide development
Sulfur, in elemental form, appears to have been the first fungicide applied to foliage, primarily for the control of powdery mildew, as early as 1821-1824. Lime­sulfur was probably the first 'manufactured fungicide, used on fruit trees as early as in 1803, for insect control and for peach leaf curl in the early 1830's. Copper Sulphate was first used in the mid 1800's in grape vine yards to discourage theft of the grapes, in the bordeaux region of France. Prof.Pierre Marie Alexis Millardet, a French scientist observed that this antitheft treatment was effective in reducing a disease called downy mildew on grapes. He formulated a safe, effective compound in 1885, known as 'Bordeaux Mixture', was the first fungicide to receive large­scale use over the world.

Preventative fungicide or Contact fungicide prevents the development of the pathogen on the plant surface before the infection occurs. The fungicide provides a chemical barrier to the pathogen and does not allow the fungus to establish. The benefit of preventative fungicides is that the plant never has a chance for yield loss and does not need to expend any energy defending itself against the infection. By their nature, preventive fungicides are 'insurance'. Since they must be present prior to disease development, the grower may apply, but no disease will show up.

Immunity of the plants consistenlty maintained even after long years of use. Helps in even ripening of berries, good retention of foliage and act as a tonic to the plants. No residue is reported either on the berries or in the soil. These are the primary advantages of using Bordeaux mixture to any systemic fungicide.

Bordeaux Mixture spray, an economic prevention, provides abroad spectrum of protective disease control by preventing or inhibiting the disease before the fungi or bacteria enter the plant. Bordeaux mixture has along residual action (ability to persist through rains and to adhere to plants) and has been successfully used forover 100 years for leafspots, blights, rots, anthracnose, downy mildew and cankers. When used as a basin drench treatment it controls the spread of root rot pathogens from diseased plants to healthy ones.

  How to prepare the Most Effective Bordeaux Mixture


Ingredients
Strength 1% ie1:1:100

Kondody's Copper Sulphate 1Kg.
Lime (Best Calcium Oxide) 700gm to 1Kg.
Water 100 litres


Take 50 litres of water and dissolve the Copper Sulphate, in the other 50 litres dissolve 700 gms lime. Use earthen, woodor plastic vessel for making the Solutions. Pour Copper Sulphate solution in to the lime Solution and stir it while mixing.

OR

Mix the Copper Sulphate solution and lime suspension by pouring them together into a third vessel and constantly stir the mixture with a wooden stick while pouring. Test the neutrality of the mixture by either dipping an old knife or do the litmus test. I kg of Kondody's Copper Sulphate requires only 700gms of chemically pure hydrated time to precipitate all the copper.

If a large quantity of Bordeaux Mixture is made, it will greatly facilitate the work to prepare stock solutions in advance. To make a strong solution, hang a jute sack of Copper Sulphate so that the bottom of it dips a few inches only in the water. The Copper Sulphate will dissolve overnight. Kondodys Copper Sulphate dissolves in water to the extent of about 2.5 kg per 10 litres (25 kg per 100 litres). If more than this is placed in the sack described above, then a saturated solution will be obtained and it may be used without serious error to prepare a 1% Bordeaux Mixture.


  Test Bordeaux Mixture before use

Performing any of the following tests can test the safety of the Bordeaux Mixture:

Litmus test: The Bordeaux Mixture is alkaline in reaction if it contains more proportion of lime. It should, therefore, turn red litmus paper blue. An excess of copper compound in the mixture may be dangerous to foliage of many plants and is indicated by solution turning blue litmus paper red.

Copper deposition test: To test the neutrality of the mixture, dip a brightened iron knife for a minute in the mixture. If the knife remains bright, the mixture is correctly prepared. If the knife turns rusty brown or if its brightness is lost, add more lime solution and the test repeated till no such deposit appears on the clean metallic surface.


  How to get best results from the best Bordeaux Mixture
  • Use Kondodys most superior Copper Sulphate dark blue crystals / Granules or Sugar crystals.
  • Use the best quality lime for a neutral mixture only 700gms of Calcium Oxide (Quick lime) for lkg of Copper Sulphate (1%).
  • pH of the mixture, between 9 to 10 for maximum efficiency.
  • Adjuvants like spreaders and wetting agents may be added to the mixture to enhance the sticking efficiency.
  • The mixture tends to sediment easily. Therefore, its stirring while using is desirable (a wooden stick is ideal)
  • Do not use the Bordeaux Mixture in combination with any other chemicals or pesticides.
  • The application of the mixture should be done on time with adequate coverage underneath the leaf surface for the effective control on the spread of the fungus to newly generated young shoots.
  • Avoid spraying in exceptionally hot days, when the plants are showing signs of temporary wilting or in case of continuous and heavy rains.
  • The left over Bordeaux Mixture should not be dumped in the field, as this may prove toxic to the subsequent sowings.