GRDC stubble management guideline No. 15
Stubble borne diseases
Cereal dominated crop rotations combined with stubble retention practices can elevate the occurrence of stubble borne diseases such as;
- Yellow leaf spot (YLS)
- Spot form net blotch (SFNB)
- Crown rot
- Net form net blotch (NFNB) in wheat
- Scald in barley
Strategies for avoiding stubble borne diseases are:
- Rotation: rotation in a paddock minimises the risk of the same stubble type being a source of disease infection. Break crops are key!
- Planting resistant varieties: consult Winter cropping summary 2017 for disease ratings
- Fungicide regimes: timing the right fungicide rate, to the right growth stage is critical for optimal impact of applications
- Predicta B test prior to sowing can identify a number of diseases that may be prevalent in a paddock, allowing a change to the sowing program to occur.
- Controlling the green bridge: control weeds that can host stubble borne diseases
The removal of stubble as a means of controlling stubble borne diseases can be a risky practice as the benefits of stubble retention are lost. The management practices of slashing, cultivation, grazing or spreading will not eradicate stubble borne diseases rather, help to spread the inoculum.
As part of the ‘maintaining profitable farming system with retained stubble in Victoria and Tasmania’ project, Birchip Cropping Group (BCG), Southern Farming Systems (SFS), Irrigated Cropping Council (ICC) and Victorian No-Till Farmers Association (VNTFA) have investigated stubble diseases and their influence on stubble retained systems.
Field trials and observations from the grower groups have been conducted as part of this project which has been supplemented by previous research and anecdotal evidence from industry experts and experienced growers across Victoria. This output has been primarily focused in the Wimmera and Mallee region and the Victorian irrigated region.