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Include ARIZONA in Winter Barley at T2 for Ramularia protection

T2: the optimum time to protect against ramularia

Even though conditions have remained largely dry in recent weeks, and the majority of winter barley crops look relatively clean, it is still important to protect the upper canopy against the latent threat of ramularia, especially as any stress caused by the ongoing dry period could increase the risk of infection.
Include ARIZONA in Winter Barley at T2 for Ramularia protection

The most effective timing to protect against ramularia is at T2 (GS39-49): applying a broad spectrum of fungicides (including the multi-site active, folpet) at this timing will protect the emerging flag leaf and help to reduce spikelet mortality, prolong canopy duration and increase the final number of grains per ear.

Efficacy and resistance management

Resistance to single site chemistries means that controlling ramularia has become more challenging in recent years: prothioconazole and SDHI chemistries are less effective due to a developing resistance problem, while strobilurin-based fungicides are no longer effective against the disease. Likewise, whilst Revysol delivers some activity against ramularia, it is not fully effective.

Ramularia can therefore only be controlled effectively through the application of a multi-site fungicide such as ARIZONA (500g/l folpet): this should ideally be used at T2 when its inclusion within the tank mix at 1.0-1.5l/ha will provide robust protection against ramularia and provide some useful supplementary activity against brown rust and mildew (plus additional activity against rhynchosporium). ARIZONA can also be used at T3 (up to, but not beyond, GS59).

The inclusion of ARIZONA will also give the added benefit of protecting other chemistries as part of a resistance management strategy.