AgMemo Northern Agricultural Region

Minimise early disease risks in your crops

Powdery mildew
Risk of early powdery mildew in cereal crops can be minimised through some simple disease management strategies.

While waiting for the break of season, it is a good time to consider what pro-active management strategies you can employ to reduce early disease risks in your crops this season.

Summer rainfall created green bridge in some areas that may still remain and that could harbour disease or disease vectors (eg aphids).

The Department of Agriculture and Food, Western Australia (DAFWA) has some key tips to minimise your early disease risks:

  • Keep up to date with disease forecasts via the Crop disease forecasts page. Forecasts are currently available for canola blackleg, field pea blackspot and field pea seed borne mosaic virus.

  • Check out the PestFax map showing what diseases were reported from your area last season to give you an idea of what diseases might be a higher risk this season. Be sure to subscribe to the pestfax newsletter if you haven’t already to receive information on pest and disease finds across the WA wheatbelt this season. Pestfax has commenced for this season and powdery mildew has been reported on volunteer wheat in the Esperance region.

  • Protecting WA Crops is DAFWA’s new monthly eNewsletter providing agronomists and growers with an up-to-date review of the weed, disease and pest threats that impact on crop production. It is a rebranding of the E-weed newsletter.

  • Control green bridge - It is crucial to destroy any volunteer cereals and weeds at least 4 weeks prior to seeding to reduce risk of early rust, powdery mildew and wheat streak mosaic virus (WSMV) infection in your new crop this season. Weeds can also carryover other crop diseases such as grassy weeds and volunteers hosting root or crown diseases and root lesion nematodes.

  • Plan variety choices and crop rotations to minimise disease risks: Understand the factors contributing to disease risk in each paddock (eg. stubble, soil borne inoculum) to determine if that will influence your crop or variety selection for that paddock or adjoining paddocks this season. Be aware of the major diseases associated with each crop and variety in your area - give preference to varieties with some disease resistance. Crop rotation or removal, incorporation or burning of stubble can reduce risk of stubble borne diseases: canola blackleg, Fusarium crown rot, field pea black spot, barley net blotch, scald wheat yellow spot, wheat septoria nodorum blotch, powdery mildew in wheat or barley. Crop rotation is also effective for managing soil borne diseases and pests such as Rhizoctonia bare-patch, take-all, and root lesion nematodes. Sclerotes of Sclerotinia stem rot in canola, lupins, chickpeas and lentils can survive in soil for up to 6 years so non-host species (such as cereals) should be grown for at least 3 years in paddocks that were recently affected to reduce disease risk. Find out more crop specific disease management, research results and the disease ratings of different varieties on the Crop Disease webpage of the DAFWA website.

  • Soil test for root diseases and nematodes if you observed any uneven growth or bare patches in your crops last year. For more information see Root diseases under intensive cereal production systems and Root lesion and burrowing nematodes in Western Australian cropping systems.

  • Consider seed or in-furrow fungicide treatments registered for the diseases your crop could be at risk from (including smuts, and foliar and root diseases). Remember in-furrow fungicides will not control smut diseases. Information on registered seed dressing and in-furrow fungicides for cereals is available on the DAFWA webpage.

  • In the absence of seed or in-furrow fungicides, crop monitoring is very important to identify disease risks. Early foliar fungicide application applied in a timely manner can be effective.  Information on registered foliar fungicides for cereals is available on the DAFWA webpage.

For more information contact:

Plant Pathologists - cereals

Ciara Beard, Geraldton on +61 (0)8 9956 8504.
Geoff Thomas, South Perth on +61 (0)8 9368 3262.
Andrea Hills, Esperance on +61 (0)8 9083 1144.
Kith Jayasena, Albany on +61 (0)8 9892 8477. 

Plant Pathologists - canola

Ravjit Khangura, South Perth on +61 (0)8 9368 3374.

Root diseases

Daniel Huberli, South Perth on +61 (0)8 9368 3836.

Nematodes

Sarah Collins, South Perth on +61 (0)8 9368 3612