West: Warm rain increases disease pressure
Welcome warm rain at the end of April has increased the potential of all recently sown spring crops. Slug activity is still surprisingly being found on some winter wheat crops, so vigilance is needed to ensure safe emergence of spring crops. Some flea beetle damage has been observed on emerging linseed.
Autumn sown crops are generally looking well. Oilseed rape canopy management treatments have suppressed apical dominance. We now have well branched canopies. Sclerotinia treatments have also been applied. Significant investment in these crops has been needed to ensure good weed and disease control – we hope they fulfil their potential.
Winter wheats also are looking well with T1 treatments being completed according to growth stage. Yellow rust has been well controlled where robust T0 treatments were made – but the risk of reinfection in many varieties is still very high as we go into May, so further treatments are planned. Septoria risk will have increased with rainfall and higher temperatures, and we have used SDHI chemistry to boost the T1 mixes.
Winter beans look so much better than last year and look promising. Plant populations are good and flowering has started and the first fungicides are being applied.
Our thoughts are now turning towards next year’s cropping and the spotlight is again based around blackgrass. I recently came across an old [1993] Farmers Weekly feature on Cheetah [fenoxaprop]. The main point of the article was that with this new contact acting product for wheat, there would be less need in the future for soil acting chemistry (in those days IPU). It was suggested that residual chemistry was more unpredictable being affected by moisture and seedbed conditions.
Twenty years on with inability to rely on contact products, we again need to go back and base our blackgrass control policy on soil acting chemistry. Luckily this last autumn we had very good weed control from autumn residuals in our wheat crops. This was partly because it was possible to control flushes of blackgrass before crops were sown, and also because good moist seedbeds allowed the autumn residuals to work really well.
However, we could easily have high dormancy blackgrass and dry cloddy seedbeds this autumn, in which case patience to delay drilling may be crucial – even if unpopular.