SIX YEAR STUDY SHOWS SHRINKING SECOND WHEAT DISADVANTAGE

The performance disadvantage of second wheats has continued to shrink over the past year, maintaining the clear trend evident since the beginning of the new millennium, according to the latest ProCam Agronomy study.

Harvest records from more than 1300 wheat crops drawn from the company's national 4cast performance database show second wheats yielding an average of 8.51 t/ha in 2006 against 8.9 t/ha for first wheats. This brought the yield gap down to less than 0.4t/ha for the first time ever, as against over 1t/ha in 2001 (Figure).

"Although crop performance has fluctuated from year to year, our six year study shows a steady upward trend in average first wheat yields from around 8.5 t/ha in 2001," points out ProCam technical agronomist, Nick Myers. "Over the same period, though, average second wheat yields have increased at more than double the rate from under 7.5 t/ha to over 8.5 t/ha.

"At a standard £80/t wheat price to eliminate the effects of market fluctuations, our analyses also show gross margin trends paralleling the yield improvements. Average first wheat margins have increased by around £29/ha since 2001 with second wheat margins going up by over £70/ha. So while second wheats were generating margins a good £80/ha less than first wheats five years ago, the gap is now only just over £40/ha.

"Encouraging too is the fact that the 2006 yield gap was even smaller amongst our top 25% crops, second wheats at 9.74 t/ha being only 0.3t/ha down on first wheats at 10.04 t/ha."

Nick Myers finds the narrowing of the second wheat performance disadvantage particularly welcome with improved prices persuading growers to think more positively about second wheats again for the coming season.

He sees it is as a just reward for the efforts their growers and agronomists have been putting into raising second wheat performance in recent years, underlining his long-standing belief that the performance of second wheats can be brought far closer to that of first wheats with improved agronomy.

"Until five years ago the only defence against take-all was to delay drilling until mid-October," he recalls. "While this helped avoid the disease, we know the best time to sow wheat if we want to maximise yields is September. So it was very much a case of swings and roundabouts.  Under these circumstances, most people just accepted that second wheats were the poor relation and made the best of the bad job.

"The arrival of the specialist take-all seed treatment Latitude in 2001, though, shone a fresh light on the problem. It has definitely improved yields in itself. We invariably see an extra 0.25-0.50t/ha benefit from treatment, with the greatest improvements from the earliest drillings. And the very fact that treated second wheats can be drilled earlier without an increased take-all risk has been a tremendous boon for growers keen to minimise the risk of failing to get drilled-up.

"Together with the effective take-all treatment, what we've really seen in the past six years is a change in attitudes. Growers have set out to cut the second wheat performance gap. And as they've done so they've started treating their second wheats as a distinctly different crops. Choosing varieties specifically suited to the slot, for instance, as well as drilling earlier, taking steps to enhance autumn establishment and improving spring fertiliser, fungicide and PGR management.

"It's this attitude change, more than anything else, I have no doubt is behind the particular second wheat progress we are recording these days," Nick Myers concludes.

"We still have more variability in second wheats that we'd like and there's no doubt that first wheats remain more profitable on average. However, with the 4cast figures showing our top 25% second wheat crops outperforming our average first wheats by a good 0.8 t/ha last year and earning gross margins of over £75/ha more, there clearly remains considerable room for further improvement on many units."