Pythium root rot

Pythium root rot


  • Pythium root rot is widely spread across cropping soils
  • Generally more prevalent when annual rainfall is greater than 350mm, in reduced tillage systems with high organic matter and acidic-neutral pH
  • All major grain crops and pastures in Australia are hosts to Pythium


  • Affects germinating seeds and seedlings
  • Continuous impact throughout the season
  • Seedling damping-off and spindly stunted seedlings
  • Root systems are yellowed/browned and stunted, with few lateral roots
  • The first true leaf in cereals is often short, twisted and cupped


  • Yield penalty can be severe


A diverse crop rotation, as well as sowing undamaged, robust seeds at the correct depth and with adequate nutrition can increase yields by reducing the incidence of Pythium. Pythium-selective chemical control with fungicide seed dressing can significantly reduce soil-borne inoculum levels and frequencies of root infections.





Links and Resources

DEPI VIC - Identification and management of field crop diseases in Victoria. - Pythium root rot

Symptoms, lifecycle, and management options. Information is in the pulse section. Published 2012.

GRDC - Curing the 'common cold' of cropping systems

Information on pythium infections, occurrence, symptoms, and control. Published 2004.

GRDC - Root Disease Fact Sheet

4 page PDF. Introduction, identification, symptoms, testing, management, and frequently asked questions. Published 2010.