CropAlert — Early Disease Risk July 2022

CropAlert — Early Disease Risk July 2022

Diseases are being observed in cereals and pulse crops in Victoria that warrant proactive fungicide applications to avoid losses. Diseases include stripe rust in wheat, ascochyta blight in lentil and bean, and botrytis grey mould/chocolate spot in bean, lentil and vetch. It is relatively early in the season for these diseases indicating that there will be high disease pressure for crops in spring.

Given the outlook for an average to wetter than average August/September, growers and advisors are encouraged to inspect these crops and monitor closely for these crop diseases with a view to timely fungicide application if warranted. It is important to consult a 2022 disease guide to check variety ratings as ratings may have changed.

A copy of the 2022 cereal and pulse disease guides are available from Apple Books (just search ‘Victorian disease guide’ in the Apple Book store) or the AgVic website for just click Pulse disease guide or Cereal disease guide.


Stripe rust

Relatively early reports of stripe rust were expected given the widespread green bridge across eastern Australia this season. The early detection indicates that stripe rust will be common across Victoria during the spring months and proactive management will be required in susceptible varieties to avoid losses.

Wheat crops across the state should be monitored for rust with a view to timely fungicide application if warranted. Given the early detection, two fungicide applications may be required to avoid losses in susceptible varieties. The StripeRustWM App can be used to help make decisions about fungicide application timings. It is important to consult a 2022 cereal disease guide to check variety ratings to this strain. Note that some wheat and durum cultivars are now more susceptible to this new strain of stripe rust.

Stripe rust identification, management, and epidemiology can be found in ‘Identification & Management of Field Crop Diseases in Victoria’.

Growers and advisors are encouraged to adopt a three-step approach to assess stripe rust infection.

  1. Review variety ratings using a current cereal disease guide. To ensure the ratings are current do not use one from previous years. The current Victorian guide can be found here.
  2. Monitor crops closely
  3. Use the StripeRustWM app to support decision making. The app can be downloaded from the Apple and Google Play stores. A user guide is also attached for those unfamiliar with the app.


Ascochyta blight

Current cool, wet conditions have been ideal for the development of ascochyta blight in pulse crops. If heavy rainfall occurs during podding, this often results in pod infection.

The ascochyta blight pathogen that infects chickpeas is particularly aggressive and growers will need to monitor their crop carefully and be very proactive in their disease management.

In other crops the disease can reduce crop yields under severe conditions. Early detections and consistent moist canopies will allow the disease to spread and may become severe if conducive conditions persist. Early infection will result in a higher chance of pod infection later in the season if rainfall occurs during podding. Pod infection can lead to seed discolouration which results in discounted prices or grain being rejected by some buyers.


Botrytis grey mould (BGM)

Early intervention is critical to minimise damage as this disease can develop rapidly with the right weather conditions. If symptoms are visible, then fungicide application is recommended, even pre-canopy closure.

If no symptoms are visible pre-canopy closure, then the preventative fungicide at canopy closure as per normal recommendations should provide adequate protection against botrytis grey mould in lentils. If rainfall continues a follow up fungicide may be necessary.

The same pathogen that causes BGM in lentil also causes BGM in vetch. Therefore, vetch crops can act as a reservoir and spread from vetch to lentil crops. All vetch varieties are susceptible to botrytis grey mould. Growers are encouraged to consider the end use of the crop when making fungicide decisions, in addition to the adjacent crops.

With recent wet conditions, all pulses growers will need to be pro-active with their disease management. This applies to all diseases in all crops. It is advisable to check the latest disease ratings and the relevant definitions for the disease ratings in the 2022 Pulse disease guide.


Further information

Further information on these and other field crop disease can be found in the online Identification & Management of Field Crop Diseases in Victoria manual.


Horsham Field Crop Diseases research group (Agriculture Victoria)

For further information and assistance in diagnosing field crop diseases, contact the Horsham Field Crop Diseases research group.

Ph: (03) 4344 3111

Email: [email protected]


Kind regards,

The Horsham Field Crops Pathology and CropSafe teams

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