Plants were inoculated with a suspension of pycnidiospores when they reached the three- to
four-leaf stage. The isolate used (Mp 91.31.12) was very aggressive on pea and representative
of the French collection. The pycnidiospore suspension was prepared as previously described
(Onfroy et al. 1999) and its concentration was adjusted to 106
spores per ml. One drop of
Tween 20 was added as a wetting agent and the spore suspension was applied (0.5 ml per
plant) with a hand-held garden sprayer. After inoculation, each tray was covered with a clear
plastic cover to maintain 100% relative humidity and plants were regularly sprayed with