Second Wheats Repay Management Attention

May 2004 - Putting more management attention into second wheats will pay handsome dividends in the coming season, believes ProCam technical agronomist, Nick Myers, pointing to second wheats on many of their customer's farms comfortably out-performing first wheats on many others.

"Second wheats have always been a poor relation for many," he explained. "But they need not be. For the past two years, for instance, our clients' Top 25% performing second wheats have generated gross margins at least £50/ha more than their average first wheats through a combination of higher yields and lower growing costs."

The secret of this success have been agronomic recipes designed to overcome the special challenges faced by second wheats, particularly take-all.

"If you grow second wheats, our experience is that you must manage them in every way possible to minimise the risk of take-all," Nick Myers insisted.

"We've found establishment is the first, most critical consideration. Be attentive. Cultivate the ground early and dry. Avoid compaction on the one hand and fluffiness on the other, rolling wherever conditions allow. Do everything you can to encourage strong initial root growth.

"Interestingly, ploughing seems to have a distinct edge for second wheats. Our comprehensive 4cast management system database shows an average 0.5t/ha yield advantage for ploughed as against min-tilled second wheats over the past four years. In all probability this comes from a combination of better initial soil conditions, trash burial and weed control.

"Having created a decent seedbed, drill your second wheat as early as you can before conditions deteriorate," he continued. "Don't take a week's rest once you've finished drilling your first wheat. Keep going to get the crop in as promptly as you can. One of the great advantages of putting first wheats in early is you can bring your second wheat drilling forward to give the crop better establishment conditions. Our best crops are invariably sown-up by the second week in October."

Good quality, appropriately-dressed seed of the right variety is Nick Myers' next second wheat priority. He sees big, bold and vigorous seed as essential in getting the crop off to the best possible start, so it can grow away from any take-all. And he has no doubt some varieties are better suited to the rotational slot than others.

"More of our customers' top performing second wheats are Consort than the three next most popular varieties put together," he observed. "Hereward and Napier also seem to perform particularly reliably in the second wheat slot.

"Regardless of variety, a specialist take-all seed treatment is vital," he added. "Especially so with earlier drilling. Latitude (silthiofam) has a clear edge in this respect. Last year, amongst our Top 25% second wheats it gave a yield advantage of 0.6 t/ha over other single and multi-purpose dressings." Nick Myers also believes many growers should maintain seed rates at close to traditional levels. Second wheat establishment tends to be more variable and at modern low seed rates crops are invariably too thin.

"You need a target of at least 200plants/m2 at post winter and this means 300 seeds/ m2 or more at drilling," he suggested. "Avoid putting the seed in too deep if you can, as well. Although drilling at 25-30 cm gives some protection from slug attack, we've found shallow drilling really helps in getting crops away."

"Sufficient and sufficiently early spring N is the other really important essential in our view. You need a good top dressing of 60kg/ha or more as early as you can get on in the spring to ensure the crop avoids nitrogen stress. And overall, we reckon 200 kg N/ha is probably the minimum rate for the crop under most circumstances. Wise use of key trace elements like manganese wherever conditions dictate is vital too."

Rather than a disease of second wheat, Nick Myers sees eyespot as primarily a disease of early sowing. He recommends an appropriate fungicide for all September-sown crops and generally considers it advisable in most seasons for all sowings of varieties which do not boast Consort-level eyespot resistance.

Aside from any possible take-all reducing value, about which he remains to be convinced, he also favours early strobilurin applications for the good physiological benefit they can give.

"By getting their management right in these important respects, many of our growers generate very handsome second wheat performances that more than justify the crop's place in the rotation," concluded Nick Myers. "And with the uncertain yields and management hassle a growing number are discovering in growing winter rape these days, this is probably just as well."