Disease severity of fungicide resistant Leptosphaeria maculans isolates, 14P286 to 14P291, on different aged leaves in the presence or absence of fluquinconazole compared to the susceptible isolate, D13.

All fungicide resistant isolates caused significantly more disease on fluquinconazole-treated seedlings than the sensitive isolate at all growth stages. Although not fully virulent on cotyledons, the fungicide resistant isolates were equally virulent on both bare and fluquinconazole treated seedlings at the 1st, 2nd and 3rd leaf stages. Disease severity scores are an average of eight replicate plants.