How do winter wheat varieties perform when sown very late?

Tuesday, 19 December 2023

With large areas of winter wheat yet to be drilled, many farmers are considering their options. Paul Gosling, who leads the Recommended Lists (RL) project at AHDB, explains what we know about the latest safe-sowing dates for varieties, as well as the potential yield impacts associated with very late sowing.

Long spells of wet weather have hampered winter wheat drilling in many areas. In such seasons, more attention is paid to the ‘latest safe-sowing date’ line in the winter wheat recommended list.

The late-sown trial series

Each year, a small set of RL trials is deliberately drilled ‘late’ – between 1 November and 31 January – with yields recorded. Most are drilled in late November, although some have been drilled into January.

After January, winter wheat is only tested in non-yielded vernalisation plots to provide latest safe-sowing date information.

The yield data from the late-sown series is usually added into the main trial dataset. However, because so much wheat potentially still needs drilling, the RL team has extracted and analysed the late-sown RL data (2019–23) to assess the impact on variety performance (for crops drilled in January).

What do the trials show?

Although the yield data is limited or very limited (for the newest varieties), the very-late-sown trial report can help growers decide whether to drill winter wheat late (if conditions allow) or to switch to a spring crop.

The good news is that all winter wheat varieties on the current RL (2024/25) can still produce respectable yields when sown in January.

Some varieties show better relative performance in this late-sown slot, such as KWS Cranium, RGT Bairstow and KWS Brium. High-yielding feed wheat Champion also continues to perform well. These varieties (among others) have latest safe-sowing dates that run into February.

On the flipside, some other varieties show a relative drop in performance, such as Gleam and SY Insitor.

Based on RL vernalisation data, the safest RL 2024/25 varieties for drilling until the end of February are:

  • Skyfall
  • KWS Brium
  • RGT Bairstow
  • Swallow

Without speculating on yield-potential impacts, these varieties have shown good (high to full) levels of vernalisation, even in plots sown into late March.

However, to minimise risk, we recommend that you stick to the latest safe-sowing dates published in the RL.

At the other end of the spectrum, the varieties at greatest risk of vernalisation issues after January include Crusoe, KWS Dawsum, Costello and RGT Wilkinson, with KWS Extase following close behind.

If you are considering drilling a variety after the latest safe-sowing date, check with the breeder/agent first, as they may have more information about the risks.

Futher information

Download the very-late-sown winter wheat trial report

See the latest regional planting intentions for harvest 2024