RESPONSE OF SUBTERRANEAN CLOVER VARIETIES TO CERCOSPORA DISEASE UNDER A CONTROLLED ENVIRONMENT AND IN THE FIELD

Seventeen commercial cultivars of subterranean clover and 10 introduced lines were screened for resistance to cercospora disease (caused by Cercospora zebrina) under a controlled environment, and responses were compared with their performance in the field. There were large differences between varieties in the severity of cercospora disease under both conditions. There was, overall, good correlation between data from the field and those from the controlled environment for the different parameters. Daliak, Dalkeith, Esperance, Mt Barker, Nungarin and Rosedale were highly susceptible to cercospora disease under both controlled environment and field conditions, while Clare, Larisa, Meteora and Yarloop were assessed as having a high degree of resistance under both conditions. A few individual resistance rankings varied widely between the 2 conditions. The results indicate that controlled conditions can be used to identify resistant lines.