Appearance of strains of Puccinia horiana tolerant to triazoles and strobilurin in England
In England, there are recent reports of Puccinia horiana (Basidiomycetes: Uredinales – EPPO A2 quarantine pest) strains tolerant either to triazoles (propiconazole, myclobutanil) or to both triazole and strobilurin (azoxystrobin) fungicides. It is also noted that tolerance to carboxamide fungicides has also been reported elsewhere in Europe. It is stressed that the appearance of tolerant strains to various fungicides may render the control of P. horiana increasingly difficult in practice.
Cook, R.T.A (2001) First report in England of changes in the susceptibility of Puccinia horiana, the cause of chrysanthemum white rust, to triazole and strobilurin fungicides.
New Disease Reports, volume 4.