Transform Second Wheats With Bold New Approach

July, 2006 - UK growers should transform their second wheat performance by making the same leap forward they did with first wheats over a decade ago, suggests leading UK breeder, Bill Angus. And he should know, having been heavily involved with the earlier drilling revolution that boosted first wheat yield potential by a good 1t/ha in the 'Eighties and 'Nineties, as well as breeding some of the country's very best second wheat varieties in Deben, Einstein and now Hyperion.

"Moving first wheat drilling forward from early October to the third week in September was worth an extra 1t/ha," he recalls. "It enabled the germinating crop to make the most of the available soil temperature, emerging in little more than a week rather than nearer three. This gave it a critical establishment edge going into the winter, setting-up far better spring growth and development to optimise yield potential.

"What earlier drilling also did, though, was to create a new crop," argues Bill Angus. "One with very different weed, disease, pest and lodging control challenges from the past. So it demanded a bold new approach, with better varieties and altogether greater precision in their management to deliver the goods.

"This extra breeding and management effort has certainly been rewarded in the dramatic improvement in first wheat yields achieved by most growers over the past 10-15 years. "And, every bit as importantly, it has given far greater performance consistency from crop to crop and year to year."

Moving first wheats on in this way, of course, has widened the performance gap with second wheats in recent years, leaving them increasingly exposed as poor relations - and, for many, of questionable profitability in the post-subsidy world.

But Bill Angus is convinced this need not be the case, insisting that growers should seize the opportunity to improve second wheats in almost exactly the same way they did with first wheats. Especially so as wheat market prospects improve, better performing varieties are identified and the limitations of growing more oilseed rape in UK rotations become apparent.

"Yes, second wheats do present a distinct challenge - not least from root and stem diseases like take-all and eyespot," he accepts. "And inputs may have to be a little higher as a result. However, I have no doubt that a bold, forward-looking approach, growing and managing them for the different crops they clearly are, will more than repay the extra effort.

"After all, in terms of yield potential we know the best time to drill wheat across central and eastern England is mid-September regardless of whether it's a first or second crop. So if we're serious about making the most of second wheats, we should do whatever it takes to get the crop in the ground and established well from earlier sowing.

"It has only been recently, with the advent of the specialist take-all seed treatment Latitude (silthiofam), that this opportunity has really been available to us," points out Bill Angus. "At the same time, the significant extension of Recommended List trials on second wheats in recent years has enabled us to better identify varieties with the all-round toughness to fit this rotational slot."

Averaged across all current varieties, the RL shows second wheats at a yield disadvantage of more than 13% (1.4 t/ha) to first wheats. However, varieties like Savannah, Cordiale, Einstein, Ambrosia and Hyperion stand out for losing less than 12% of their first wheat yield when grown in the second slot. Equally at the other end of the scale, Claire loses nearly 16% and Robigus over 18% (or more than 2t/ha) even with the prophylactic eyespot sprays applied as routine in the RL trials system.

These figures clearly support Bill Angus' conviction that good variety selection is fundamental to second wheat success. He insists that only varieties with the right combination of characters will deliver the consistent annual performance so vital today.

Particular variety essentials in this respect, he believes, are stiff straw to withstand the higher levels of nitrogen required; good across-the-board disease resistance - especially to eyespot; and high specific weight plus the ability to 'finish' the grain well under less than ideal conditions.

"As far as eyespot is concerned, I'd certainly be looking for the much stronger VPM resistance as well as seeking RL ratings of 6 or more," Bill Angus advises. "Equally, I'd want a Septoria trictici resistance score of 5 or more in a strong overall disease package. And I'd go for varieties with a good stiff straw and specific weights of at least 76 kg/hl. I must stress, though, in my experience no one character makes a good second wheat. It's the best possible combination you really need.

"You also need to be sowing it in the final two weeks of September rather than early or even mid-October. Which means you can afford to reduce seed rates - from say 300-350 seeds/m2 to 200-250 seeds/m2 with Einstein, depending on conditions; particularly if you use vigour-tested seed.

"Reducing seed rates, of course, will be very valuable for your spring management, giving you more leeway to increase nitrogen use without increasing lodging risk," he adds. "What's more, it will make it possible for you to invest in the insurance of a Latitude take-all treatment where there is a significant threat from the disease at little or no extra cost."

As well as underlining the clear superiority of varieties such as Deben and Einstein over the likes of Claire and Robigus, Nickerson's variety trials at a consistently challenging take-all site in Suffolk confirm the advantage of Latitude over non-specialist seed dressings even with mid-October sowings (Table).

Table: Nickerson UK Take-all Challenge Trials (2004 harvest)

"All the evidence points to the take-all seed treatment giving a similar yield lift regardless of variety," notes Bill Angus. "So, while it may get a poor second wheat out of trouble, your greatest value will undoubtedly come from combining it with the best possible variety. This will be particularly critical when you're putting both to the challenge of September rather than October sowing.

"You'll also need to fine-tune your crop nutrition, fungicide and PGR management too," he suggests. "After all, it's absolutely no use boosting the growth and yield potential of your crop if you fail to adequate protect and support it with a good programme of fertilisers, fungicides and PGRs.

"Just like September-sown first wheats, a new approach to second wheat growing will undoubtedly make the whole job more demanding and may require a greater initial investment in inputs. But in boosting yields by even 0.5 t/ha, let alone the tonne I'm sure is available to most growers, it will substantially cut growing costs/tonne."

So what does Bill Angus see as the single most important ingredient for second wheat success?

Not the right variety. Not a specialist seed treatment. Not even earlier sowing at a lower seed rate. No, he has no doubt whatsoever that the magic ingredient has to be an approach to second wheat that recognises the crop is fundamentally different from first wheat and will repay the extra management effort.

"Either you treat second wheat as a necessary evil and make the best of a bad job," he challenges growers. "Or you recognise the opportunity it so clearly offers and make the very most of it by doing it as well as you can. The choice is yours.