Abstract
Perithecia of Mycosphaerella graminicola (Fuckel) Schroeter and Leptosphaeria nodorum Müller developed on the dead leaves of wheat stubble soon after harvest. The ascosporeswere liberated in the presence of free water on the dead leaf surface. They were still being liberated 8 months after harvest, when spore-trapping stopped. It is suggested that wind-borne ascospores initiate infections on young crops growing at a distance from wheat stubble.