VARIETIES AND LINES OF WINTER-WHEAT WITH STABLE TOLERANCE AND LOW-YIELD LOSS TO SEPTORIA-NODORUM (BERK)

Inoculated field tests determined the reaction of winter wheat to Sept oria nodorum during 1991-93. Tolerance to the pathogen was found in on ly 4 % of the 750 entries screened. Only 11 varieties and one breeding line showed very stable tolerance. In eight of these entries, the ear s were more infected than the flag leaves. The variety Turda was the m ost tolerant entry, as determined by low loss of yield. In this group of entries, there was no significant correlation between visual sympto ms of infection and yield reduction. Six entries were highly susceptib le and gave consistently high yield losses. These entries and the stab le tolerant ones could be used as comparative standards for screening tests on the field.