Tillage Update - 18th February 2021
Shay Phelan, Teagasc Crops Specialist has the update on winter barley and winter oilseed rape crops for the week. He advises carrying out plant counts at this time in winter barley. He refers to pigeon grazing and light leaf spot in winter oilseed rape and also has advice on dealing with cover crops
Winter Barley
Winter barley crops have progressed well over the recent weeks with very little “yellowing” of crops so far. While growers may be happy with this it may also point to a lower demand for nitrogen, phosphorous and potassium due to the crops crop being thinner or having lower tiller numbers than normal. Either way farmers should try over the next week or so carry out some plant counts to establish is this is the case or not.
Many growers are asking the question again this year should they go with early nitrogen to drive the crops on? While many growers are convinced that there is a benefit, research work form Oak Park has repeatedly shown that where plant numbers and tiller numbers are adequate there is no advantage in applying nitrogen in February, especially if soil temperatures are low.
However the research has also shown that where nitrogen fertilisers are applied in late February that the yield penalty is relatively small. Therefore growers with large areas to cover, can in some confidence, spread the workload in the knowledge that yield penalties shouldn’t be too big.
Winter Oilseed Rape
Most crops are progressing well with small green buds starting to appear on some crops. Nitrogen strategy will depend on the green leaf area of the crop so before any fertiliser is applied all crops should be assessed for their GAI. Remember each one point of GAI signifies that crop already has approximately 50 Kgs/ha of nitrogen stored within the leaves and this is a real saving in fertiliser costs.
Pigeon grazing is a bigger issue in crops this year and some crops have been severely grazed in the last few weeks. Remember that they are removing leaves that contain nitrogen so in order to get most out of the fertiliser nitrogen that is being applied then every effort needs to be made to move them on.
Light leaf spot will probably need to be treated in the coming weeks, most crops received no fungicide last autumn so the likelihood is that they will needed treatment in the next couple of weeks. Choice of products will depend on whether the crop needs a PGR effect or not, products containing metconazole or tebuconazole will give some effect while prothioconazole will have no pgr effect.
Dealing with Cover Crops
Before many fields can be drilled this spring the existing cover crops will have to be handled. Some have been grazed but many have not, these will need to be destroyed as soon as possible especially if they contain volunteer cereals and you aim to grow cereals. These volunteers can carry over diseases and pests such as rynchosporium or aphids which can transfer directly onto the emerging crops. Most crops will be burned off with glyphosate while others will be disked in. Ideally crops should have six to eight weeks between destruction and drilling the next crop.
Drilling into standing cover crops is now becoming more common but again beware of the potential risks involved with direct transmission.
Tillage Conference Part 2
The second part of the National Tillage conference was held on Wednesday 17th. The topics discussed were:
- Developing IPM strategies for controlling septoria tritici in winter wheat – Steven Kildea
- Herbicide resistant grass weed; Problems and the way forward – Vijaya Bhaskar
- Crop establishment systems and rotations in combination - Dermot Forristal
View Conference recording below:
More information on the 2021 National Tillage Conference is available here