Yellow leaf spot in stubble retained systems

Property owners: Pete and Vicki Stuckey.

Property size: 10,000 ha

Enterprises: Cropping, merinos and fat lambs, beef cattle (Shorthorn and Angus).

Soil and pH: Red soil with pH of 5.6.

Overview:

Pete and Vicki farm a dryland property 25 km north of Condobolin.  They crop wheat, barley, oats and canola and also grow field peas and lucerne as break crops.

Their farm is divided into areas of continuous cropping and grazing for livestock and traditional mixed farming, though this regime isn’t set in concrete and may change in the future.

They use an agronomist, Chris Baker. The wheat crops followed field peas, canola or long fallow with only one paddock of wheat on wheat. One paddock of Suntop wheat however showed a small amount of the disease that was noticed by his agronomist though Pete noticed none himself.

Sowing:

Although not a big issue in the past to prevent a re-occurrence in one particular paddock (of older farming country) this year they applied good early nutrition with 80kg MAP followed by 60kg of urea as the season progressed with good rains and plentiful soil moisture.

The paddock affected followed a long fallow and Pete believes any yellow leaf spot that was present survived on grasses during a pasture phase.

Disease management:

Pete and his agronomist decided nutrition was a better form of control than fungicide application and the disease seemed to disappear after that.

They missed the opportunity for a second application of urea but the disease is now barely noticeable in the paddock and expected yield loss from it will be minimal.

Next year they plan to grow barley in that particular paddock.

In the future if wet seasons persist, Pete sees there could be a problem with yellow leaf spot in situations where wheat is continually cropped. However if the break crops they are now growing become uneconomical other options may be considered.

At this stage though they will not burn stubbles even if affected by yellow leaf spot as Pete feels the benefits of retaining stubbles far outweighs that of burning and would prefer to grow a break crop.

Yellow leaf spot is it worth spraying?

For some additional information on the identification of yellow leaf spot feel free to watch the video below with Steven Simpfendorfer.

 

 

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Project Name: Maintaining profitable farming systems with retained stubble in Central West NSW

Project Number: CWF00018