A survey of New Zealand certified barley seed for the presence of pathogenic Drechslera species

Two Drechslera spp., D. teres (conidial state of Pyrenophora teres ) and D. sorokiniana (conidial state of Cochliobolus sativus ), were found on New Zealand certified barley seed produced during the 1974–75 and 1975–76 seasons; 74% of barley lines tested were infected with D. teres and 15.5% with D. sorokiniana . Seed lines from the North Island carried the most infection, 100% being infected with D. teres and 40% with D. sorokiniana , and in South Island lines, 59% were infected with D. teres and 2% with D. sorokiniana . The mean percentage infection per seed line averaged 21% for D. teres and 2% for D. sorokiniana (44% D. teres and 5% D. sorokiniana in the North Island; 8% D. teres and 0.3% D. sorokiniana in the South Island). No differences in cultivar susceptibility were detected. D. graminea (conidial state of P. graminea ) was not detected.