Downy mildew

This fungus is distributed worldwide. It causes leaf spotting that spoils the quality and appearance. Leaf spots begin as indefinite yellowish areas on the upper leaf surface. A mat of grey to violet mould develops on the corresponding lower surface. With time under cool, wet conditions, the spots enlarge until the whole leaf turns black and dies. The fungus increases profusely in high humidity. The spores can over-season in mild climates in living spinach, in seeds and in the soil.