Factors affecting the germination of Septoria nodorum pycnidiospores

Most pycnidiospores of Septoria nodorum were released from pycnidia into water in 30 min, more than 50% being released in 10 min. The viability of pycnidiospores in aqueous suspension, assessed by germination on a selective agar medium, decreased more rapidly in daylight than in darkness but no spores germinated after 50 h. The presence of cirrhus extract stimulated germination of pycnidiospores in suspension.