Comportement des cultivars de peuplier envers la rouille

Abstract

Between 1987 and 2010, more than one hundred poplar cultivars were tested in order to assess their behaviour towards larch rust (Melampsora larici-populina). For most of them, we determined in the laboratory the virulences required to infect them. Then all clones were submitted to infection in three nurseries with a selected inoculum that reflected the diversity of the pathogen races. Susceptibility levels are provided for two periods and the virulences required for infection are given. Almost all the clones selected for complete resistance have lost this characteristic and the resulting infection level is often heavy, especially on inter-American clones.