Weather

The weather forecast over the coming days shows scattered showers and temperatures are cooler, with some colder nights, so spraying might be hard to get right. However, colder weather may reduce disease levels.

BYDV

There are plenty of yellow leaves, in spring barley crops in particular. Late sowing in April and May was always going to result in a high threat of virus. Most farmers did their best to spray at the optimum timing, to control aphids which spread the virus, the three- to four-leaf stage. However, barley yellow dwarf virus (BYDV) is very hard to stop and maybe infection would have been worse if crops had not been sprayed. For now though, you will have to look at those yellow leaves for another while. There is no benefit to spraying a second time. The damage is done now. Crops are infected and a second spray could contribute to resistance build-up.

Fungicides

T1s are now due on many spring cereal crops. On spring barley the ideal timing for the first fungicide is mid- to late-tillering. You need to keep leaves clean and stop disease from getting into the crop. At T1 something like Proline plus Comet is a good choice. A strobilurin like Comet is needed for net blotch control on susceptible varieties like Planet. Some people will prefer to go for an SDHI based product like Mandarin or Elatus Era at T1. There are a number of mixes available. On oats, a Proline and Comet mix could be used, along with a mildewcide if needed. T3s on winter wheat should be applied at mid-flowering. This spray should have an azole like Proline or Prosaro.

Wild oats

If spraying for wild oats or canary grass later in the season keep to high rates of 0.6l/ha of Axial. If canary grass is present and the crop is advanced, you may need to use 0.8l/ha of Axial Pro. If a hormone herbicide has been applied to a crop, do not apply Axial Pro until three weeks after its application. Axial Pro can be applied with sulphonyl urea-based products and products like fluroxypyr. However, if these products have been applied, Axial Pro cannot be applied for 21 days after this.

Growth regulators

Some spring barley varieties with poor straw strength will benefit from a plant growth regulator. Moddus should be applied before GS33 on spring barley. Medax Max and Terpal should be applied before the flag leaf has fully emerged. You should not need more than one of these products. For spring oats Teagasc advises Ceraide at GS30-31 to crops with a high lodging risk and Moddus or Medax Max at GS32 to give a maximum shortening effect.

Beans

Use beans to control grass weeds and apply Falcon or a similar product where grass weeds are present before flowering. Signum, Amistar or Elatus Era are choices for the fungicide at the start of flowering. Some foliar phosphorus and potassium might help with downy mildew control.