After the disasters in viticulture caused by powdery mildew and phylloxera, the fungal disease "downy mildew" was introduced into France from America in 1878. Alexis Millardet (1838-1902), a professor of botany at the University of Bordeaux, developed what he named "Bordelaise pulpe" and recommended it in 1885 as a successful remedy against this new and hitherto unknown fungal disease. The discovery was more or less due to a coincidence. Millardet noticed that the vines of one vineyard were infected with this disease, but the neighbouring vineyard was not - with the grapes of these healthy vines covered by a light blue layer. He asked the vintner and he said that he had sprayed the grapes with a mixture of lime and copper sulphate to deter thieves (a common practice at the time). Millardet then began experimenting and created the light blue mixture of copper sulphate, lime and water. The remedy still proves its worth today in the fight against many vine diseases caused by fungi and bacteria. However, prolonged use can lead to an accumulation of copper in the soil, which can be counteracted by adding lime to the soil. Bordeaux broth is one of the few chemical preparations that are also permitted in organic viticulture. See also under vine enemies.
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