Winter has been a very brief affair so far, with the recent snow and frost being replaced by high pressure pushing warm weather from the south.
With land now drying out, I have been clocking up the miles around these fields again and making a few very tentative plans – though it doesn’t pay to get too carried away in February up here.
It is fairly obvious just from the greenness of the countryside that nitrogen carryover has been more plentiful this winter. To help assess this, we’re doing as much mineral nitrogen testing as we can in order to guide our nitrogen plans. The results that have come in so far point to some high readings, although there is some variation depending on field history. There are obvious peaks where organic manures have been applied but there are also results over 100kg even in its absence in some cases.
Winter barley crops are starting to discolour as this nitrogen starts to diminish and so will be a priority for early nitrogen splits. I always remind growers that with barley, it’s all about biomass to support high tiller numbers and as such you need to keep the crop going. Mildew has continued to linger in many of our crops and will be a priority for control when we are clear of frost. Interestingly, the handful of crops that received mildewicide last autumn now look markedly greener.
Yellow rust in winter wheat has been suppressed by recent frost but will need watching as the weather warms. Septoria is also very prevalent but no action is required at this stage. Many of our wheat crops have a good plant population and high biomass which should lead to good potential.
Early nitrogen management will need careful consideration this year so that we don’t encourage too much early growth and tillering and end up with flat crops. As a general rule, I’m suggesting reducing the early dose on the high biomass crops and bringing in more later on when there is less chance of increasing the lodging and disease risk. I think plant growth regulators (PGRs) will also feature strongly this year.
So far temperatures are not quite there for grassweed sulphonylurea, although I have started to plan some pinoxaden on a few fields. I am, however, hoping to get on with sulphonylureas earlier this year as many of the targets such as brome are already quite large.
Pigeons are continuing their ‘canopy management’ of oilseed rape and thoughts are starting to turn to the first fertiliser splits. We need to remember that in OSR yield is not directly linked to excessive crop biomass early in the season and that we are trying to keep the crop open before building to an optimum GAI of 3.5 in early flowering. In other words, we’re trying to produce seeds not leaves. Crops with high levels of flea beetle larvae damage need to be treated as a low biomass crop to try and counteract the impact of this pest. I’m recommending sulphate levels of 75 to 100Kg/ha and if you can split it, I think it makes sense.
Light leaf spot has been slow to make an appearance in all but the lowest rated varieties. There is no doubt that varietal resistance is helping greatly in this arena. As crops start to take off we’ll need to make an assessment of the need for PGR fungicides.
Cover crops have grown well for us this winter and we are just starting to think about desiccation ahead of drilling. I’m hoping also that, by the time you read this, we may have a few beans in the ground.