Crops sat under snow for a couple of weeks in February, but generally they are looking good. Some of the earlier drilled wheats were looking quite thick, and on some of the dirtier varieties were carrying quite high levels of Septoria. The frosts in February should have helped dampen down yellow rust.
Plenty of crops were drilled in the last week of September, but then didn’t get a pre-emergence herbicide as 100mm of rain fell in the first week of October. Where residual herbicides were applied they tended to be applied post-emergence where control is not as consistent.
That means there is likely to be crops that will need weeds tidying up this spring with a mesosulfuron-based product. With less black-grass in our area
Feedback from those that used Pacifica Plus (mesosulfuron + iodosulfuron + amidosulfuron) last season was very positive. It’s good for controlling a range of broadleaved weeds and grassweeds, including bromes and black-grass.
Rye brome is becoming more of an issue in Scotland. If you’re in a mixed weed situation then Pacifica Plus is a good choice, but if you’re specifically targeting rye brome then Monolith (mesosulfuron + propoxycarbazone) is also an option.
Yellow rust will be the main driver for T0s in wheat crops, especially without chlorothalonil to control Septoria this season.
Most growers will use either strobilurin fungicides or tebuconazole for yellow rust at T0 – whether that will be in late March or into April will depend on how crops and disease develops. Coastal areas are likely to be most at risk.
There are high levels of light leaf spot in Scotland this season. Our Spotcheck service with ADAS, where you can send oilseed rape leaves to be assessed for disease, is showing very high levels of light leaf spot from samples sent in December, January and February.
So applying an oilseed rape fungicide, such as Proline (prothioconazole), as soon as you can travel will be a priority for many growers.
There were some thicker crops of August-sown oilseed rape, which might need some growth regulatory activity to bring them back, if the snow or pigeons haven’t done the job. If you need growth regulatory activity mix in some tebuconazole – you need around 25 g/ha tebuconazole / leaf for the best effect.
As growers look ahead to spring 2021, the picture is a lot better than many feared. In general, winter cereal crops were drilled in good time, and although it was wet in early October, most crops have got up and away and looking much better than they did in January 2020.
Find out more information on the key disease threats to your wheat crop. For each disease you will find out the importance of the disease in terms of potential yield penalty, how to identify the disease in its early stages and our advice on the best control strategies.
Bayer’s SpotCheck initiative, which helps oilseed rape growers identify light leaf spot (LLS) and other diseases in the crop, will re-open to receive leaf samples from October. The previous season saw epidemic-levels of disease so growers are advised to be alert to early signs of LLS and apply fungicides early.