Before phylloxera, the vineyards of Europe had been battling with powdery mildew or oidium (Uncinula necator), a fungal disease that, like phylloxera, had come from America. Unlike most fungi, oidium prefers dry conditions. The first symptoms of infection are whitish powdery patches on the undersurfaces of basal leaves, but canes, flowers, and fruit can also be affected. Diseased berries fail to thrive and may split open. The original solution of spraying or dusting sulphur onto the vines is still practised, assisted by canopy management techniques that increase air and light penetration.