A fungal disease which affects the leaves of daylilies. It is caused by Aureobasidium microstictum*, however an injury to the plant may be required for infection to take place – pest damage, for example. Symptoms include yellowing along the central leaf vein followed by browning, and reddish-brown spots. The damaged areas may join together and spread along the leaf in streaks, and infected leaves may eventually die. Cultivars vary in their susceptibility to leaf streak. Minimize overhead watering and avoid working among the plants when the leaves are wet.