Leaf Disease Complex is a catch-all title for several cereal-affecting fungal diseases, including:

  • Septoria;
  • Scald;
  • Spot Blotch;
  • Tan Spot;
  • Speckled Blotch; and
  • and others.

These are common in the County and can be found to some degree in many fields. Some of the fungi live on the straw of the plant and some are soil-borne and may persist for many years.

How is it Spread?

They are more prevalent under warm and highly humid conditions.  These diseases spread easily with wind and rain and cause damage by reducing the photosynthetic area of the plant leaves, which results in yield reduction.

What to Look For

    Septoria Leaf Disease Complex       Speckled leaf blotch

                    Septoria                          Speckled leaf blotch

    Spot net blotch      Scald

     Spot net blotch                                          Scald

   Tan spot      Barley yellow dwarf

                  Tan spot                         Barley yellow dwarf

  Spot blotch on barley

                                Spot blotch on barley


There are many tools to use in the prevention of Cereal Leaf Complex. Some of the steps you can take to reduce the impact of this group of diseases are:

  • Rotate crops with non-susceptible host plants every second year to break the cycle;
  • Use cleaned seed, preferably certified;
  • Seed resistant cultivars;
  • Treat seed with a registered fungicide at recommended rates; and
  • Apply appropriate fungicide in crop at the correct stage of the diseases.

Related Links

Alberta Government Leaf Diseases