Incidence and severity of Septoria leaf blotch in winter wheat in relation to reduced dosage of fungicides

The trials were carried out over the period 1999-2000 with a view to testing the efficacy of reduced doses of triazole fungicides on winter wheat cv. Zentos. Septoria diseases (Septoria spp.) occurred on winter wheat annually. Full and reduced dosages of fungicides were highly effective against Septoria leaf blotch at an early milk stage, especially on flag leaf. Later the efficacy of reduced dosages of the fungicides was lower, than that of full doses. Due to full dosage of fungicides we obtained a sufficient yield increase annually. The yield increase through the use of 3/4 reduced doses was lower. But yield increase through reduced dosage to 1/2 was low and insufficient.