Methods of reducing rhizoctonia patch of cereals in Western Australia

Cultivation reduced rhizoctonia patch of cereals. In a continuous cropping experiment where zero‐tillage and cultivation were compared over three seasons, cultivation reduced patch score in all seasons by an average of 83%. In the fourth season, when the treatments were reversed, the incidence of rhizoctonia patch was also reversed. Nitrogen (ammonium sulphate, sodium nitrate or urea) also reduced patch score under zero‐tillage, but sources of nitrogen did not differ significantly in their effects. In another experiment it was demonstrated that a contact herbicide used in the zero‐tillage system was unlikely to be responsible for the high incidence of patch in that system. One cultivation reduced total patch score by an average of 46% compared to zero‐tillage, but these scores were not reduced further by a second cultivation.