Risk factors to the wheat on wheat systems are disease and nutrition.
The foliar diseases yellow spot (YS) and septoria nodorum blotch (SNB) are particularly high risk when wheat is sown on wheat stubble.
Variety choice, timing of fungicide and nitrogen are tools to manage this system.
To maximise fungicide return on susceptible varieties, studies indicate the need for optimum nitrogen nutrition.
This relationship needs to be tested on newer varieties with improved disease resistance for disease management in a wheat on wheat system.
Determine the value of nitrogen and fungicide on the profitability of new wheat varieties with different disease resistances in the wheat on wheat system.