Tillage: Nitrogen is the best weapon to tackle septoria in winter wheat
Published 17/02/2016 | 02:30
This time last year, field work was underway in many areas. This year, however, it is a different story. There's no need to panic though - there will be plenty of time to get the work done, and given the proportion of land that has already has been sown with winter crops, the spring workload will be lower than normal.
When the land does dry out sufficiently to bear the weight of machinery, the first crop that will need attention is winter oilseed rape crops. Many crops had very strong growth coming into the winter to the point that there would have been problems had that growth continued into the new season.
The huge population of pigeons however, sorted that out and many fields now more closely resemble carefully mown meadows than the lush greenery they sported a few weeks ago. Crops with well-established root structures will recover rapidly once they get a small amount of nitrogen and sulphur, perhaps in urea form, to replenish leaf area as soon as conditions allow.
One issue that may occur in open crops is weed occurrence. If ever there was a demonstration in selective grazing, the ability of pigeons to graze oilseed rape plants to the clay, while leaving adjacent charlock plants completely untouched, is amazing. Where weeds are a problem, it is past the date for use of propyzamide based herbicides.
However, there is now a range of herbicides available for oilseed rape for use in warm conditions. These herbicides are more selective and expensive than residual herbicides, so correct weed identification is necessary before the correct product to use can be established.
Most winter wheat crops have emerged from the winter in rude health, and although recent temperatures have been low, there is a fear that these strong crops will carry a lot of latent disease into the spring.
Given the knife edge we are told that fungicide families are on in relation to control of septoria, careful management of these crops is essential. At this early stage in the season, controlling the leaf canopy, and therefore the environment in which septoria will proliferate, is essential.
Therefore the most effective fungicide to use at this point in the season is granular nitrogen, or to be more correct, lack of granular nitrogen.