Careful selection key to control of septoria
Final sprays are going on wheat crops, and controlling septoria is the main target. Fusarium, rusts and mildew also need to be taken into consideration when making product selection.
Controlling septoria has become more difficult over recent years, with changes in the disease's sensitivity to certain chemical families. Careful product selection with an eye to protecting the effectiveness of the control options currently available is needed by all growers.
Septoria tritici has been resistant to MBC fungicides since the 1980s. Since 2003 it has been resistant to strobilurin fungicides.
A shift in sensitivity to the triazole fungicides, Folicur and Caramba, was detected between 2004 and 2005 by the research team in Oak Park.
Sensitivity to the two most commonly used triazoles, Opus and Proline, remained stable between 2003 and 2008 and both products gave effective septoria control.
Then, in late 2008 and early last year, samples collected from some wheat crops showed reduced sensitivity to Opus and Proline in laboratory tests. The degree of insensitivity was greater for Proline than Opus.
Initial results from field trials indicate that the performance of epoxiconazole and prothioconazole appear to have been affected to some extent.
However, the other triazoles, Folicur and Caramba, were found to be effective against these particular strains of the disease.