The long awaited sunshine and increasing day length has been welcomed by growers and agronomists alike. Most of the crops have returned to a more normal green colour than the more familiar yellow colour we have been experiencing, after receiving nitrogen and nitrogen sulphur applications.
A T0 fungicide is planned for the first two weeks of April for early-drilled cereal crops and growth regulation will be applied in the form of chlormequat and Moddus (trinexapac) once final leaf 4 has fully emerged – Moddus giving added growth regulation effect as well as strengthening the stem cell walls.
Depending on variety, fungicide choice has largely been either Bravo (chorothalonil) or Cherokee (chlorothalonil + propiconazole + cyproconazole) or tebuconazole plus Bravo. Rust pressure is generally low and septoria pressure high coming out of the winter, although the drier February and March will have helped. Protection against septoria is far more effective than eradication, Chlorothalonil provides a good base with its multi-site protection.
T1s are being planned for the coming weeks based around an SDHI and triazole, with chlorothalonil again added for essential septoria protection. At the time of writing, a small amount of mildew has been seen in forward winter oats, but not in wheat or barley. If the situation changes later on and into April, a mildewicide will be added at T1. Chlorothalonil cannot be mixed with Atlantis-type herbicides so recommendations for grass-weeds were made earlier so there would be no clash when it comes to T0 applications. Gout fly has been seen in many of the early-sown crops, but we have not treated for this as these crops are strong enough and will easily outgrow it after an application of nitrogen.
Barley will most probably not be receiving a T0 this year, as disease to date has not been seen out in the field, but now I have written this no doubt it will appear. T1s are being planned for winter barley, this is likely to be kept simple with an application of Siltra (bixafen + prothioconazole). Crops are really starting to pick up after a couple of weeks of dry, sunny weather at the start of March.
Axial (pinoxaden) or Topik (clodinafop) recommendations have also been made for wild oat control in barley and wheat crops, and if tank mixes allow will be added to T0s.
Winter oilseed rape crops have all had tebuconazole in February or March for light leaf spot protection and pigeons have provided growth regulation in some crops. The next application will be green/yellow bud spray for alternaria and sclerotina control. But crops are a little way off this yet.
Spring drilling is being completed, with the first crops of spring beans and spring barley having been sown at the end of February/start of March, the pre-emergence sprays have worked well in both crops, so far. Spring barley nitrogen applications will need to be completed as soon as possible for malting crops. Soil nitrogen tests are showing low levels this spring following the high offtakes last year and so rates may be increased slightly to allow for that.
Our growers are producing malting barley to export for lager production, so a 1.65-1.85% N is the target, and higher nitrogen also increases yield so it can be a difficult balance to get right. Spring beans should be watched from emergence for weevil damage and should be sprayed as soon as the characteristic ‘u’-shaped notches are seen; it is not the adult feeding which causes the yield loss but the larvae which feed on the root nodules which are fixing nitrogen.
Ground is being sprayed off ready for maize drilling, some growers may start drilling the end of April if soil conditions are warm enough – usually 8degC plus and rising, and the risk of frost has disappeared.
Sarah Symes is an independent agronomist working with the Hampshire Arable Systems partnership. Based in Hampshire, she advises clients growing cereals, oilseed rape and pulses.