United Kinjgdom
April 21, 2017

Bayer has confirmed the presence of two new mutations in German ramularia populations that severely impact the performance of SDHI and azole fungicides, respectively.

Although field efficacy of SDHIs and azoles against ramularia in the UK remains good, the findings in Germany provide a timely reminder of the need to follow guidance issued by the UK Fungicide Resistance Action Group (FRAG-UK). 

Fungicide resistance managment

Good resistance management is based on limiting the level of exposure of the target pathogen to the fungicide.

• Fungicide input is only one aspect of crop management and other integrated control measures should always be used, such as good hygiene through disposal of crop debris and control of volunteers which may harbour disease.
• Always aim to select varieties exhibiting a high degree of resistance to diseases known to be prevalent in your area, in addition to the main agronomic factors you desire.
• Avoid growing large areas of any one variety, particularly in areas of high disease risk where the variety is known to be susceptible. Only use fungicides in situations where the risk or presence of disease warrants treatment.
• Use a dose that will give effective disease control and which is appropriate for the variety and disease pressure. Make full use of effective fungicides with different modes of action in mixtures or as alternate sprays.
• Ensure that mixing partners are used at doses that give similar efficacy and persistence.
• Monitor crops regularly for disease and treat before the infection becomes well established.
• Avoid repeated applications of the same product or mode of action and never exceed the maximum recommended number of applications. Make full use of effective fungicides with different modes of action in mixtures or as alternate sprays.

FRAG-UK guidance, which is being reviewed in light of the latest information, can be found at cereals.ahdb.org.uk/frag

Website: http://cereals.ahdb.org.uk/

Published: April 21, 2017