Occurrence of two seed-borne pathogens, Alternaria radicina and Alternaria dauci, on imported carrot seed in New Zealand

摘要

Abstract Of 86 imported carrot seed lines screened during 1968-69, 19 were found to transmit Alternaria radicina, the cause of black rot disease, and 7 transmitted Alternaria dauci, the cause of alternaria leaf blight. The occurrence of black rot infection in two commercial carrot crops and on packaged carrots is also reported. It is suggested that field occurrence of black rot and alternaria leaf blight in New Zealand could be attributable to seed-borne infection in the absence of other sources of inoculum. It is advocated that infected seed lines be identified by routine seed health tests and treated by seed merchants before being released to growers.