AbstractThe resistance of several white poplar‐clones against Pollaccia radiosa. Continuing the work of Weisgerber(1967,1968 and 1969) clone‐typical forms of resistance against spring defoliation (shoot‐dieback), caused byPollaccia radiosawere investigated in several Leuce‐poplarclones. The most obvious differences in attack occur under natural conditions. The observed differences concerning the type of resistance (infection versus spreading in the host) seem to depend on the anatomical structure of t