The Need to Use Different Ways of Applying Pesticides

In a previous Editorial, the emphasis was on the need to adopt Integrated Pest Management (IPM), but for the majority of farmers, there is the need to spray a pesticide, which hopefully will increasingly be a biopesticide, but to control certain pests, a chemical pesticide may still be required. The need to control a disease, downy mildew (Peronospora viticola) on some grape seedlings from America was detected by Millardet in France back in 1878. The disease was not adequately controlled using sulphur, but after a farmer sprinkled some water, containing copper sulphate to deter children and travellers along the highways picking the grapes, Millar det developed a mixture of copper sulphate and lime as a fungicide that was named Bordeaux Mixture, which he tested on the foliage and the mildew. According to Lodeman (1896) the first systematic applications of copper sulphate, mixed with lime were in about 1884, when it was decided that this was the most promising of all the various mixtures that had been tried. The recipe was dissolving 8 kilos of commercial copper sulphate in 100 litres of water. In another container 15 kilos of quicklime were mixed in 30 litres of water. This was then mixed with the copper sulphate and stirred well and then some was taken in a pail and sprinkled using a small broom on the vine foliage. Interestingly, Millardet thought that in the case of severe rains, it might be advisable to make a second application.