Ear Diseases

Ear diseases can affect your crops by reducing grain fill, leading to low Bushel weights and high screenings. Certain types of infections e.g. Fusarium, can also result in mycotoxin production, which can cause problems for end users. Sooty Moulds and similar diseases can cause a blackening of your grain, which in extreme cases can lead to rejection.

Ear diseases in Barley
• Effective seed-treatments have effectively eliminated seed-borne diseases Smuts and Bunt etc.
• Foliar diseases such as Ramularia, Rhycho, Net Blotch and Mildew can spread to the ears and awns.
• Specific ear and grain diseases such as Botrytis, Fusarium and Sooty Moulds tend to be prominent when wet weather occurs during flowering and grain filling.

Delaying the last fungicide until the ear is fully emerged, or applying an additional ear spray helps reduce the incidence of ear diseases in barley. However, research in Ireland has shown that in most years applying the final fungicide earlier gives a greater yield response and applying an additional fungicide late is uneconomical. In addition there are restrictions on how late you can apply fungicides depending on the crop (winter, spring and malting) and product.

Key point: In most years, the best yield response in barley is achieved by applying your final fungicide no more than three weeks after the previous fungicide even if the ear is not fully emerged (best timing to help reduce ear diseases).

Ear diseases in Wheat
Foliar diseases that affect the ear include Septoria nodorum (different from Septoia tritici which is the main foliar disease in Ireland), can potentially cause very significant yield losses (over 50%).

Specific ear diseases include:
• Sooty Moulds are common in wet weather and discolour grain but cause little yield loss.
• Fusarium ear (or head) blights are caused by a range of fusarium species.

Fusarium in Winter Wheat
Fusarium (ear blight)
Wet weather during flowering can lead to Fusarium ear blight and possibly mycotoxins.


Control of Fusarium
Control of ear blight is difficult and costly as high doses must be applied close to the infection period. Fungicide treatment can help reduce ear blight (and mycotoxin risk) provided the recommended rate is used as near to infection time as possible. This means applying your T3 spray during early flowering (GS61–65). 

Key point: Timing of the T3 i.e. during early flowering (GS 61-65) is critical for control of Fusarium.

It is important to choose a product with activity against ear diseases at T3 while also ensuring they offer additional protection against late season foliar disease. While the yield response from the T3 on average only gives a 7% yield response, in certain years the response can be very significant (in a low disease pressure year the response is very low). The results of a 2012 Teagasc trial shows the three products Dairygold recommend-Prosaro, Magnello and Gleam can give a very significant yield response in certain years.  It should however, be noted that even with these products timing is critical and that the level of disease control is lower than you would expect from foliar disease targeted apllications.


Use of Strobilurins at T3
In 2012 extensive monitoring by Teagasc showed that Microdochium species (one of the key species that cause Fusarium) had developed complete resistance to the strobilurin fungicides. For this reason strobilurins can no longer be relied upon for control of Microdochium or Fusarium head blight in Irish cereal crops.  However, despite this, it appears that they still deliver an average yield response of 0.3 tonne/hectare; making their use economical. Dairygold recommends Curator (Amistar plus Bravo-anti resistance strategy) in crops with a high yield potential

In a bad year Fusarium can be very prominent in fields

Summary of T3 Wheat Recommendations
• Use Prosaro, Magnello or Gleam at robust rates
• Include a strobilurin where crops have a high yield potential
• It is best practice to include chlorothalonil as an anti-resistance strategy

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