Citation:
Eva M. Mateo, F.M. Valle-Algarra, R. Mateo, M. Jiménez, N. Magan, Effect of fenpropimorph, prochloraz and tebuconazole on growth and production of
T-2 and HT-2 toxins by Fusarium langsethiae in oat-based medium, International Journal of Food Microbiology, Volume 151, Issue 3, 15 December 2011, Pages 289–298.
Abstract:
Fusarium langsethiae has been isolated from infected cereals in central and
northern Europe where it has been identified in the last decade as the main
species involved in the occurrence of high levels of T-2 and HT-2 toxins, mainly
in oats. The efficacy of three fungicides (prochloraz, tebuconazole,
fenpropimorph) for controlling growth of two strains of F. langsethiae isolated
from oats was examined at 0.96 and 0.98 a(w) at 15, 20 and 25 °C on oat-based
media. The concentrations necessary for 50 and 90% growth inhibition (ED₅₀ and
ED₉₀ values) were determined. The effect on the trichothecene type A mycotoxins
T-2 and HT-2 was also determined. Without fungicides both strains grew faster at
0.98 than at 0.96 a(w) and the influence of temperature on growth rates was
25>20>15 °C. Prochloraz and tebuconazole were more effective than fenpropimorph
against F. langsethiae. Strain, temperature and type of fungicide significantly
influenced the ED₅₀ and ED₉₀ values for growth. The concentration ranges under
different environmental conditions were: prochloraz (0.03-0.1 and 0.3-1.5),
tebuconazole (0.06-0.9 and 1.3-8.2), and fenpropimorph (22-59 and 125-215 mg
l⁻¹). Production of T-2 and HT-2 toxins was influenced by temperature, a(w),
type of fungicide and dose. Levels of T-2 were usually higher than those of HT-
2 under the same conditions. The biosynthesis of T-2 toxin increased after 10
day incubation, but was reduced with decreasing temperature and increasing
fungicide dose. At 0.98 a(w) T-2 levels increased in cultures containing
fenpropimorph while at 0.96 a(w) the toxin concentrations increased in response
to the other two fungicides. Low doses of prochloraz or tebuconazole enhanced
toxin production when compared with untreated cultures for strain 2004-59 at
0.96 a(w) and 20-25 °C. HT-2 was hardly detectable in the treatments with
prochloraz or tebuconazole at 0.98 a(w). This is the first study on the effect
of these anti-fungal compounds on control of growth of F. langsethiae and on
production of T-2 and HT-2 toxi