White, powdery fungal growth which develops on the top surface of the leaf and sometimes over the entire plant. Commonly affects greenhouse plants, herbs, leaf vegetables, perennials and some fruits. The affected leaves can become distorted especially if the foliage is young. Affected fruits may crack and split becasue they are unable to expand normally.
Vegetables commonly affected: Some brassicas including swede, courgettes, cucumbers, beans.
Product solution: There is currently no chemical registered for the control of powdery mildew on swede.
Cultural measures: Ensure that plants are kept well watered in dry spells and are not over fed. Remove infected plants, and any affected leaves to slow down the spread of the infection. Some cultivars show some resistance to powdery mildew.