Leaf Scald

Symptom

Symptoms are zonate lesion starting from the leaf tips and edges. Initial signs of leaf scald infection are the development of water-soaked lesions on the leaf and sheath. Lesions are oval or irregular shaped, grey-green in colour which change to a straw colour with a dark brown edge. Leaves may appear blotched and yellow lesions can merge, causing the whole leaf to wither and die. Leaf scald is a seed-borne disease, surviving from one season to the next on stubble, grass and infected seed. Initially, ‘hot spots’ of infection appear when plants are tillering, soon spreading via rainfall from plant to plant. Severe infections can occur particularly during spring when crop canopies are dense, and conditions are wet and warm. Often crops with high levels of applied nitrogen can cause infections to be more severe.