Selection of Kentucky Bluegrass for Drechslera poae Resistance under Greenhouse Conditions

Resistance to leaf spot and melting out caused by Drechslera poae was evaluated in eight cultivars and seven breeding lines of Poa pratensis under greenhouse conditions. The results obtained in this study were compared with levels of resistance scored after natural infection under field conditions during 1994–1997 in sun and shade lawn maintenance, as described before. It was found that resistance assessed in the greenhouse as leaf spots in the three-leaf seedling stage 10–14 days after the first inoculation (assessment I) and resistance assessed as severity of melting out on the crown 56 days after the first inoculation (assessment IV) showed the highest repeatability with the scores obtained in the field under sun and shade conditions during 1994– 1997.