Key Points
- At this site on a Templeton silt loam the use of irrigation during the grain fill period produced a yield difference of 2.01t/ha (20%) over the unirrigated crop.
- The increase in yield may be attributed to the increase in green leaf area retention giving a further 14 days during grain fill to make use of the available water.
- Due to the distinct lack of foliar disease pressure it was not possible to make a link between strobilurin fungicide response and available water during grain fill.
- When irrigating crops decisions should be based on the expected yield response to maximise the cost of the water and returns from that crop.
- The return of grain kg/mm declined as irrigation increased and was well below the target of 15kg/mm.
- Full irrigation at a cost of $2/mm lost $248/ha.
- There is a benefit of using strobilurins if nitrogen and water availability are adequate to support continued crop growth and that the disease spectrum is such that it is not controlled by triazoles alone.