Agronomy Update - March 2022
Richard Harris - Bartholomews Agronomist
As we approach March, it feels like winter is finally behind us, although you wouldn’t bet against some more cold wind from the east, which seems to be forming a pattern over the resent seasons.
Autumn cereals are looking generally well to forward taking the pressure off the need for big nitrogen applications and might even reduce the overall crop requirement going into the spring. What comes with this positive (given the current high fertiliser market) is disease pressure, these forward wheats, barleys, and oats are carrying some significant septoria and mildew. Without a sustained cold period, these diseases will carry into the spring. Although these diseases are on sacrificial leaves, it gives us a gauge of inoculum levels and the disease pressure we are likely to face.
Another important factor when evaluating disease pressure will be drilling date. The AHDB have recently designed a simple graph to quantify the effect of early and late drilling. The blue early sown line indicates drilling around the 22nd of September, not uncommon on heavy cold sites. The grey line indicates drilling around the 7th of October, and the green line indicating drilling around the 20th of October. Although a cautionary note to add to this will be geographic location, as crops grown in coastal areas and the south will accumulate more biomass during the winter, and therefore increased disease pressure.
On average the early sowing decreases the septoria score rating by 0.6, with the later sowing increasing the rating by 0.6. Careful consideration of drilling date and crop biomass should be evaluated now allowing for timely and precise crop protection management decisions this spring, with a varieties disease score only being one part of several management factors.
Winter oilseed rape has come out of the winter well in most areas and starting to develop visible buds in places. Disease levels seem to be low at the moment but that could all change by stem extension. The main pest to note is the pigeon - there are a number of severely damaged crops coming out of the winter which will need careful nitrogen and canopy management this spring. Fortunately, we seem to be managing the flea beetle well with our toolbox of cultural controls, enabling us to once again establish a viable crop going into the spring, something almost thought to be unachievable 4/5 years ago when we were transitioning away from the seed treatment. Certainly, a good news story for IPM.
If you want to get in touch with our agronomy team, call 01243 755610.
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