Evaluation of fungicides for curative activity against Tranzschelia discolor, cause of the rust disease of French prune (Prunus domestica L.)

Abstract

The ergosterol biosynthesis inhibitors, propiconazole, RH-2161 and RH-3866, exhibited strong curative activity against Tranzschelia discolor infections in French prune leaves. Foliar sprays (25-50 ppm) applied during the latent period, up to 7 days after inoculation, completely suppressed the disease. When these fungicides were applied after the appearance of symptoms, they inhibited further lesion growth and sporulation. Other fungicides having some curative activity were triforine and oxycarboxin. Fungicides with little or no curative activity against T. discolor were bitertanol, PP969, triadimefon and tridemorph.