All-round strength earns variety consistency crown

For the fifth year in a row DK Exsteel has performed near the top of Agrii’s extensive national variety trials, earning it the accolade of the most consistent modern-day variety seed technical specialist, David Leaper and his team have ever seen.

Undertaken at between three and four sites spanning the main OSR growing areas of the country, each season’s trials involve 40-plus current and up-and-coming varieties grown under strictly commercial production regimes. As well as up-and-coming prospects, they always include the top-performing varieties on the AHDB Recommended List and employ the same controls.

“DK Exsteel is the most consistent variety we have ever had in our trials and one of only three to merit inclusion for more than five years,” Mr Leaper stresses. “It has a five-year average gross output of 4.9t/ha, putting it at 110% of the controls (Figure).

“It has never been lower than sixth place in our gross output table in any year either, with ratings of between 104% and 118%.

“What’s more, with a gross output of 5.3t/ha (107% of controls) it was the second highest performing variety last season – within a whisker of the top slot and ahead of all three top varieties on the 2023/24 RL. And this despite having been introduced several years before any of them and not carrying the TuYV resistance trait.

So, why does DK Exsteel show such consistency and continue to perform on a par with the very best of modern OSR genetics? Well, it really comes down to the all-round strength of its breeding rather than particular ‘headline’ traits.

Specifically, Mr Leaper sees four key areas of strength that really stand out.

• Rapid autumn development as well as vigorous establishment, giving an important edge in dealing with early pest challenges and less-than-ideal conditions;

• Fast and robust spring regrowth, enabling the most reliable recovery from any CSFB larvae and pigeon damage;

• Very high phoma (8) and light leaf spot (7) resistance ratings plus good verticillium resistance, ensuring the best foliar and stem health; and

• Strong standing power and stem stiffness with Dekalb pod shatter resistance, providing the best yield insurance and the greatest combining flexibility.

“Years of experience from a large number of our growers as well as performance in our trials shows DK Exsteel suits a wide range of situations and regimes,” he points out. “This is hardly surprising since, just like previous grower favourites, Excalibur, DK Extrovert, DK Expower and DK Exalte, it has been bred, first and foremost for on-farm reliability.

“We see the hybrid as ideal for anyone putting high output consistency above the latest (and far less widely proven) varieties. As well as being one of the best choices for sowing well into September if this becomes necessary, a rapid autumn growth habit makes it well-suited to those combatting cabbage stem flea beetle with earlier August drilling.

“DK Exsteel has been one of our best-selling varieties for several years now, and we confidently expect it to be so again for another season in which minimising growing risk continues to be one of the most important OSR priorities for many.”

Figure: DK Exsteel Performance in Agrii National Variety Trials 2018-2022