CROPS WATCH: Controlling volunteers in spring barley

Many spring barley crops are due their first spray of the season in the coming days or when the weather allows.

This year has sparked new challenges for some growers, as the remains of forage and cover crops, from the winter just past, begin to emerge.

While these volunteers may look problematic at present – many forage rape plants are towering over spring barley – they are easily controlled.

In this installment of CROPS WATCH, in association with TerraChem, John Mulhare starts a plan for this crop of spring barley.

The crop of Prospect was planted on March 22 and received 4,000 gallons of pig slurry per acre.

As the crop was sown in March and is at a lower risk of Barley Yellow Dwarf Virus (BYDV) John is considering leaving out the aphicide.

Herbicide application

Volunteer forage rape is a problem in this crop. Other weeds include small broad-leaved weeds like speedwell and fumitory.

Cameo Max will be used to target the small broadleaved weeds. Where wild oats are being sprayed John would usually use Galaxy as the second herbicide to ensure a broad spectrum of control and to implement an anti-resistance strategy.

However, this year he will be using Kinvara, which contains MCPA as well as fluroxypyr and clopyralid. The hormonal element of this product (in the MCPA) will result in a quick turn down of the forage rape’s leaves.

Wild oat spray cannot be added to a tank mix with Kinvara and should not be applied until two weeks have passed following the application of the hormonal product.

As the field has a known manganese (Mn) deficiency, John recommended 0.75L/ha of manganese Aloy. K2 will also be applied to promote tillering and even out the crop.

Herbicide application:
  • Cameo Max – 45g/ha;
  • Kinvara – 2L/ha;
  • Manganese Aloy – 0.75L/ha;
  • K2 – 1L/ha.

Omnera – which is a sulphonyl urea in liquid form – provides an extra kick of fluroxypyr where resistant chickweed is a problem. It can be applied at the full rate of 1L/ha or at the reduced rate of 0.75L/ha where additional fluroxypyr is added.

Fungicide application

Proline and Treoris is the plan for the T1 fungicide at present, but this could change as the season progresses. The variety rates at a score of eight for mildew and so should not need a mildewcide.