Crown rot and take all can be easily confused as they both cause “whiteheads” after flowering.  The whiteheads caused by crown rot will be scattered throughout the paddock and not all tillers will affected, while take-all will tend to be in patches.  The base of the plant will also have different symptoms; Crown rot causes the base of the plant to be honey coloured or dark brown.  Take-all causes blackening of the roots, sub-crown, internode and stem base.

The fungus that causes Crown rot can survive on decaying stubble and is only transferred to the crop by direct contact.  To reduce the risk of infection inter row sowing is effective if your seeder is set up for this.  Otherwise the most effective management options for 2008 are to choose paddocks with low levels of disease and that finish well, match nutrition to potential yield (especially N) and choose tolerant cereal types.

The fungus that causes Take-all can only survive on a living host and quickly declines if the soil is moist and there are no hosts present.  To reduce the risk of take-all infection use fertiliser/seed treatments, use less susceptible cereal types, make sure there is adequate nutrition (especially P and Mn), control hosts at least 3 weeks before sowing.

AUTHOR: Cathy Paterson, Research Officer - Soil Compaction, SARDI

CONTACT: For further information please contact the Minnipa Agriculture Centre on 08 8680 5104.