Crown rot puts another sting in the tail for 2006

The 2006 winter cropping season has been a tough one across much of the northern grain zone. Unfortunately losses due to crown rot may make it even tougher.

High levels of crown rot are now being found in northern wheat crops - even in the most resistant varieties - prompting a warning for advisors and grain growers to get into their paddocks now to check which ones are affected.

The warning has come from the Northern Grower Alliance (NGA) and NSW Department of Primary Industries (DPI) who are running large scale ‘inter-row sowing’ trials across northern New South Wales as part of ongoing research into the intractable disease.

NSW DPI plant pathologist Steven Simpfendorfer said growers should now be looking for basal browning in every wheat crop planted in cereal stubble or with a one-winter break.

“Many of the crops appear to be performing quite well, but with closer inspection it is clear that extensive basal browning is occurring in many crops,” Dr Simpfendorfer said.

“This is likely to disappoint growers who traditionally look for whiteheads to appear; which is not a reliable indication of the full extent of the problem.

“We are urging growers to get a better picture of their crown rot status before considering locking into contracts which they then may not be able to fill.”

Crown rot causes a honey brown discolouration at the base of infected tillers. Under moisture stressed conditions the disease grows rapidly through the plant, restricting water movement and resulting in whiteheads which contain little or no grain.

NGA Chief Executive Officer Richard Daniel said while nothing can be done to manage the disease in affected crops, it’s vital that growers know the extent to which individual paddocks are infected so they can better plan rotational strategies.

“The disease will survive in stubble for long periods, so it’s important to identify high risk paddocks and then adjust the long term management,” Mr Daniel said.

“We need to assess and record the level of crown rot in these crops before harvest, to ensure high risk paddocks do not get planted back to back with wheat.”

Rotation with broad leaf crops such as chickpeas, faba beans and brassicas or summer crops is the best management tool. It is critical to ensure grass weeds are well controlled during the entire rotation phase.

NGA is fully funded by the Grains Research and Development Corporation who also fund the collaborative crown rot research with NSW DPI.

Email: