The French botanist Jules Émile Planchon (1823-1888) studied pharmacy and medicine in Montpellier and returned to this university as professor of botany from 1853. In the meantime, he had worked at the Royal Botanical Gardens of Kew in England and as a teacher in Ghent and Nancy. In 1868, together with the vineyard owner Gaston Bazille (1819-1894) and the horticulturist Félix Sahut, he was commissioned to investigate the cause of the mysterious vine death that subsequently occurred throughout Europe. Within only two days, these three experts succeeded in identifying phylloxera as the cause. When they dug up some rootstocks of diseased vines, the roots seemed to be covered with yellow varnish due to the large number of vine lice.
Planchon immediately suspected that there must also be a winged form of these insects and indeed discovered such on the wilted foliage of the vine with a magnifying glass. These specimens were equipped with two pairs of transparent wings and resembled the oak parasite "Phylloxera quercus" in an astonishing way (however, the two insect species are not related). This is why Planchon aptly named the devastating pest "Phylloxera vastatrix" (devastating/destructive louse). Planchon, in collaboration with other experts, only became aware of the fact that phylloxera had been introduced from America years later during a study trip to the USA in 1873.
The French government had already created a commission to combat phylloxera in 1870, which examined over 700 proposals. Planchon had met the American entomologist Charles Valentine Riley (1843-1895) during his trip to the USA. With him, he found the solution known as grafting, which is still valid today, by grafting scions onto American rootstocks. It should be mentioned, however, that others, such as the above-mentioned Bazille and the biologist Georg Engelmann (1809-1884), had also proposed this solution before. However, it took nine years to allow the import of American vines and years of trials to select rootstocks resistant to phylloxera and compatible with the various European soil types.
Decisive work was done, among others, by Pierre Viala (1859-1936), who led a delegation sent to the USA by the French Ministry of Agriculture in 1887 and received important information there from the American botanist Thomas Volnay Munson (1843-1913). Further years passed before the grafting solution advocated by the "Americanists" prevailed over the chemical control solution advocated by the "Sulphurists". It is very likely that with the extensive import of American vines, the great third plague downy mildew spread. And again it was Planchon who identified this dangerous fungus in 1878. In 1880 Planchon described the grapevine species Vitis berlandieri and named it after the Swiss biologist Jean Louis Berlandier. In 1893 a monument with his bust was erected in Montpellier and in 1910 the square was named after him.
Portrait: By wellcomeimages, wellcomecollection, CC-BY 4.0, Link
Statue: Par S. Rouchaléou - From Montpellier, photo by DePlusJean, CC BY-SA 3.0, Lien
