Developing an effective disease control programme this season

Even though the inclement weather conditions have prevented field activities across the country, disease has been advancing throughout crops.

The increasing temperatures and high humidity are ideal conditions for the growth of the common cereal foliar diseases.

Crops of winter barley (variety specific) have mildew and rhyncho present, whereas winter wheat crops – particularly in coastal regions – are presenting with mildew, septoria and, in some cases, yellow rust.

Disease control programmes are going to start in the next few days and product choice has never been as important.

Winter barley

Due to its growth habit, winter barley is a crop that needs to achieve optimum growth between the periods of GS29 to GS32.

This is a key yield-building phase in the life cycle of the plant and if it is lost, it can be very difficult to regain later in the season.

With regards to a primary winter barley programme applied at GS31/GS32, Terrachem agronomist John Mulhare states that the programme of choice will contain a SDHI+triazole+chlorothalonil mixture. This recommended programme has proven to be very cost effective over the last number of years for its resistance and high yields.

Varieties

Disease control strategies will vary according to the disease present. For example, Mulhare states that in varieties Cassia and Infinity, using the fungicide Treoris® (2.0L/ha) plus Proline® (0.6L/ha) will be the core programme.

However, where mildew is present in Cassia or Infinity (both scoring five on the national list), the addition of a knockdown mildewicide – such as Corbel® – combined with the preventative mildewicide, Talius®, is recommended.

In the hybrid varieties, using a slightly different programme such as Treoris® (2.0L/ha) plus Proline® (0.4 L/ha) will suffice.

Mulhare notes that where mildew is active, it is essential to allow for the addition of a knockdown and/or a preventative mildewicide.

Winter wheat

In winter wheat, the principal disease is septoria. However, varieties like Avatar and Torp are also presenting with mildew.

Mulhare said: “Septoria in particular can quickly spread to the active growing tips of plants if not tackled quickly and effectively.”

In order to prevent both septoria and mildews, Mulhare recommends a programme containing Vareon® (1.0L/ha) plus Treoris® (2.0L/ha).

In coastal regions north of Dublin, where yellow rust is presenting in crops, exchanging Vareon® to an epoxiconazole or cyproconazole triazole fungicide mixed with Treoris® will be a more appropriate option.

Treoris® as a wheat fungicide contains the SDHI penthiopyrad and the active ingredient chlorothalonil found in the brand Bravo®.

From a non-disease perspective, Treoris® and specifically the SDHI element of the mix has proven to boost root and shoot development compared to any other members of this SDHI chemical family.

Treoris® has been proven to add to the plant biomass and the subsequent yield potential of the crop. Click here for more information on disease control