Implications of crop rotation and fungicide on the Fusarium and mycotoxin spectra in Manitoba barley 2017-2019

Citation

M.N. Islam, M. Banik, S. Sura, J. Tucker and X. Wang. Implications of crop rotation and fungicide on the Fusarium and mycotoxin spectra in Manitoba barley 2017-2019. 2022 annual meeting of Canadian phytopathological society (virtual), July 4-8, 2022.

Plain language summary

Fusarium head blight (FHB) is one of the most important diseases on barley in Manitoba. Little is
known about the Fusarium species and mycotoxin spectra associated with FHB of barley in this
region. Hence, barley grain samples were collected from 149 commercial fields from 2017 to 2019,
along with information on respective cropping history, and analyzed with respect to Fusarium
species spectra, abundance, chemotype composition, and mycotoxin profiles. The results show
Fusarium poae is the predominant Fusarium species associated with FHB of barley in Manitoba,
followed by F. graminearum and F. sporotrichioides; F. equiseti and F. avenaceum were also
detected but only at low levels. F. poae strains with the NIV chemotype and F. graminearum
strains with 3-ADON and 15-ADON chemotypes were commonly detected in the barley grain
samples. Nivalenol (NIV) and deoxynivalenol (DON) were the two most important mycotoxins
contaminating Manitoba barley. A substantially higher DON content was detected in grain samples from barley fields with cereals, compared to canola and flax, as the previous crop. Furthermore,
F. poae proved less sensitive to four triazole fungicides (Caramba, Prosaro, Folicur, and Proline)
than F. graminearum. Results from the current study can assist Manitoba barley producers in better
understanding FHB threat levels and optimizing practices for the management of barley FHB.

Abstract

Fusarium head blight (FHB) is one of the most important diseases on barley in Manitoba. Little is
known about the Fusarium species and mycotoxin spectra associated with FHB of barley in this
region. Hence, barley grain samples were collected from 149 commercial fields from 2017 to 2019,
along with information on respective cropping history, and analyzed with respect to Fusarium
species spectra, abundance, chemotype composition, and mycotoxin profiles. The results show
Fusarium poae is the predominant Fusarium species associated with FHB of barley in Manitoba,
followed by F. graminearum and F. sporotrichioides; F. equiseti and F. avenaceum were also
detected but only at low levels. F. poae strains with the NIV chemotype and F. graminearum
strains with 3-ADON and 15-ADON chemotypes were commonly detected in the barley grain
samples. Nivalenol (NIV) and deoxynivalenol (DON) were the two most important mycotoxins
contaminating Manitoba barley. A substantially higher DON content was detected in grain samples from barley fields with cereals, compared to canola and flax, as the previous crop. Furthermore,
F. poae proved less sensitive to four triazole fungicides (Caramba, Prosaro, Folicur, and Proline)
than F. graminearum. Results from the current study can assist Manitoba barley producers in better
understanding FHB threat levels and optimizing practices for the management of barley FHB.