West: Tough fungicide choices coming up

February again and is spring just around the corner? It certainly seemed like it 10 days ago with fields looking as green and advanced as a normal March. The cold snap has steadied things up and at least the Charlock looks a bit sicker now. Once again frost had the greatest effect where SOLA bifenox was applied previously.

A striking effect of the mild winter was seen last week in South Wales in a BYDV trial. Untreated plots and the guard area around the trial were heavily infected; plants in these areas had roughly half the biomass of those in the treated areas.

Most cereals have high shoot numbers and will require careful nitrogen and PGR management. Even with high levels of mildew winter barley still carries lots of tillers. Wheat is very similar with early drilled Grafton carrying 10 or more tillers. Don’t forget that HGCA lodging rating is not an absolute figure and can vary by several points depending on sowing date and shoot number. Root lodging is likely to be most severe in early sown, over thick crops so take every step to keep these crops in check.

Grass weed control has been generally good in cereals with virtually all the bad blackgrass fields receiving their full programme of treatments before Christmas. We even managed to treat a few fields with post emergence materials in January – they have worked very well. A few later ones will need a tidy up as soon as this cold snap passes and soil temperatures rise.

Oilseed rape continues to produce leaf and large canopies are the norm. We have been monitoring carefully for light leaf spot but so far have failed to find infection. All crops had a prothioconazole treatment in late autumn for Phoma. We will ensure that our stem extension PGR fungicide has good light leaf spot activity.

Looking ahead, my inbox and desk top are creaking under the weight of SDHI promotional material. I think fungicide selection this year will be like picking an England rugby team! Will it be a complete clear out of the old stagers or will there still be few places for the old heads? None of the older fungicides have retired yet but perhaps a few are showing their age! The triazoles certainly need more help to do the same as 10 years ago.

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