Effect of three systemic fungicides on deoxynivalenol (vomitoxin) production by <i>Fusarium graminearum</i> in wheat

Abstract

The effect of triadimefon, propiconazole and thiabendazole fungicides on the growth of Fusarium graminearum and the production of deoxynivalenol in wheat was investigated in a field trial. The heads of wheat plants were infected with F. graminearum spores (1 × 10 5 conidia mL −1 , approximately 62.5 mL m −2 ) 2 d following anthesis. Triadimefon (Bayleton 1.8 E.C), propiconazole (Tilt 3.6 E.C) and thiabendazole (Mertect 340-F) were sprayed at the dosages of 60, 120, and 360 g a.i. ha −1 , respectively. Treatments of wheat plants with the fungicides were conducted at three time schedules: (1) one application at 2 d before inoculation, (2) one application at 2 d after inoculation, and (3) two applications at 2 d before and 2 d after the inoculation of wheat plants with F. graminearum. Treatments with triadimefon and propiconazole fungicides resulted in 39–61% and 34–79% decreases in F. graminearum infection and deoxynivalenol levels, respectively. Although treatment with thiabendazole resulted in the maximum reduction (83%) in deoxynivalenol level, it had no significant effect on F. graminearum infection.Key words: Fusarium graminearum, deoxynivalenol, vomitoxin, fungicides, triadimefon, thiabendazole, propiconazole