Tillage Update - 19th November

Mark Plunkett, Soil & Plant Nutrition Specialist reports from a number of tillage fields with Martin Bourke, Tillage Advisor, Wicklow on how crops have developed. Over the last number of weeks crops are emerging well with good leaf, tiller and root development.

Winter crops are turning greener in the fields which is a great sign that crops are healthy and establishing well despite the wet weather since sowing. The weather has been quite changeable with significant rainfall amounts over the last month, reducing the opportunity to complete field operations such as weed control and BYDV treatment in winter cereals.  

In the Fields Crop Update

Winter Oilseed Rape Crops of winter oilseed rape are developing well despite the majority of crops sown in September. To date broad leaf weed control has been good and there has been the opportunity to tidy up volunteer cereals.  Disease levels are reported to be low, continue to monitor crops for phoma and light leaf spot and where there is greater than 10% infection of either disease apply a proline / prosaro type fungicide.

The benefits of applying organic manures are very evident in OSR crops this year. Currently researchers at Johnstown Castle are evaluating the suitability of different types of organic manures for tillage crops on the farm of Sylvester Bourke, Arklow, Co. Wicklow. This trial (Nutri-Cycle) clearly demonstrates the benefits of applying organic manures to OSR crops, as crops have produced leaf canopies very rapidly despite the later sowing. This trial will provide a great insight into the fertiliser replacement value of different organic manures and their role in supplying and building soil carbon and biology on continuous tillage soils.

Winter Barley & Wheat Where pre-emergence herbicides have been applied weed control to date is good with good activity on difficult weeds such as cleavers, speedwells and grass weeds.  Good weed control can be attributed to good herbicide activity in the damp and warm soil conditions at time of application. Assess these crops and control remaining weeds with a suitable herbicide in the springtime. Where crops have not been treated for weeds to date apply a broad spectrum herbicide when soil conditions allow. Select herbicides based on field history, weeds present and adjust application rates based on weed size.

BYDV Early sown crops will be at higher risk to BYDV infection compared to later sown crops. The ideal time for applying an aphidicide is at the 2 to 3 leaf stage.  Mid-October sown crops will be at or approaching the correct stage for BYDV control.  Assess crops for the presence of aphids before treatment; aphids are two to three times more likely to be near field headlands than out in the field. Crops in coastal regions will also be at higher risk to BYDV infection.  Where aphids are present apply an insecticide.

Volunteer Cereals The effects of Storm Ellen & Francis are still visible especially in winter barley crops that follow spring barley crops. Volunteer spring barley plants are now showing signs of both net blotch and rhyncosporium (see figure 4). This will be a source of infection for newly emerging winter barley plants.  Monitor these crops over the coming weeks / months for disease development.

Monitor Pest Activity Crops planted in the last 10 to 14 days will be slower to emerge. Pay particular attention to emerging crops especially after oil seed rape / bean crops as the risk of slug damage tends to be higher.  Where seedbeds are cloddy there will be increased slug activity under current damp soil conditions.  Monitor crops for slug activity by placing a number slug traps in recently planted / emerging crops and treat crops where you see more than 5 slugs per trap.

Trace Elements There have been reports of trace element deficiencies on the lighter / black soil type’s especially in winter barley crops. Check soil test results and monitor crops regularly. Treat crops based on soil test results or where there is a known history of a trace element deficiency.  Aim to treat crops with a foliar trace element from the 2 to 3 leaf stage.