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Strong T2 treatments needed to control increasing septoria risk

Reports are coming in thick and fast from across the UK of significant levels of disease in wheat crops, with septoria lesions rapidly building in many areas.
Septoria infections are particularly severe this year, thanks in large to the prolonged wet and mild conditions that dominated the winter and early spring.

In fact, disease pressure is so intense in some regions, that even those varieties that usually remain relatively clean are showing significant septoria lesions – all the way from the stem base to the tip of newly emerging leaves. 

Those same wet conditions prevented many early season (T0 and T1) treatments from being applied on time, with some growers also choosing to reduce the level of protection provided at these timings as they were wary about spending too much on crops with relatively low yield potential. 

However, historical evidence and recent experience tells us that crops which receive a lighter treatment at T0 and/or T1 will be at higher risk of infection developing in the upper canopy. 

Applying a well-timed fungicide treatment containing a cost-effective array of active ingredients at T2 will therefore be critical to ensuring the top two leaves remain as clean as possible so that crops can go on to perform to their true potential. 


With that in mind, T2 treatments should contain a combination of curative single-site active ingredients as well as a protectant multi-site active, the latter of which will help the crop’s upper canopy to remain greener for longer, therefore providing a significant boost to yield and quality potential.  

Using ARIZONA in partnership with single site actives can also help to enhance their efficacy, as shown in the graph below. 

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Including ARIZONA in T2 treatments with Univoq gives a clear yield benefit. Trials have clearly shown that the best approach is to use ARIZONA at T1 and T2, but it still provides a clear advantage even if it wasn’t applied at T1. 


Where possible, three modes of action should be used at T2. For example: 

  1. an azole  
  2. an SDHI or Qil fungicide (e.g. fenpicoxamid) 
  3. a multi-site (folpet) 

Whilst the azole and SDHI components will provide strong protection against septoria and other fungal diseases, the efficacy of some of these single site actives is under pressure as a result of sensitivity shifts in the septoria population. As a newer active ingredient, fenpicoxamid isn’t yet under the same resistance risk as older azole and SDHI chemistries, but it is a single site active and must therefore be protected. 

A combination of active ingredients including folpet should therefore be used to provide maximum protection against diseases and to slow down the erosion in efficacy of the ‘at risk’ chemistries. 

Including ARIZONA (500g/l folpet) in the T2 tank mix will protect these single site actives by reducing their exposure, and will also provide an additional, cost-effective layer of protection in its own right.  


  • Use a balanced mixture of compatible fungicide modes of action 
  • Include ARIZONA (500g/L folpet) to improve septoria control and reduce the resistance risk for single site active ingredients 
  • ARIZONA should be included at 1.0-1.5 l/ha: the optimum dose rate will depend on the prevailing risk factors (varietal disease resistance rating, drilling date, time gap since the T1 treatment was applied, underlying disease pressure). In most scenarios 1.0 l/ha of ARIZONA in mixture with partner products will suffice, but in higher risk cases the rate should be increased to 1.5 l/ha 
  • ARIZONA helps to extend the green leaf area duration of the upper leaves of wheat plants. This puts the plant in the best position to capture available sunlight during the grain fill phase, which translates through to a direct yield benefit. 

For more information about ADAMA’s folpet-based fungicide, ARIZONA, click on the product image below. 

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ARIZONA® (500g/l folpet) is a unique multi-site protectant fungicide for wheat and barley, providing an anti-resistance strategy for the control of septoria and a range of other cereal diseases.