Latest Study Shows Shrinking
Second Wheat Disadvantage

July, 2006 - The performance disadvantage of second wheats has shrunk appreciably over the past five cropping years as growers across the country have taken increasingly positive action to improve their crop management.

This is the encouraging finding of a new study conducted by ProCam Agronomy with its national 4cast crop performance database.

Although crop performance has, understandably, fluctuated from year to year, the study shows a steady upward trend in average first wheat yields from around 8.5 t/ha in 2001 to 8.9t/ha last season. Over the same period average second wheat yields have also trended upwards, but at approximately double the rate - from under 7.5 t/ha to nearer 8.4 t/ha (Figure 1).

Figure 1: UK Wheat Performance Trends (2001-2005)

"Altogether the yield gap has declined from around 1t/ha in 2001 to 0.5t/ha last year," points out ProCam technical agronomist, Nick Myers who undertook the study.

"What's more, at a standard £70/t wheat price to eliminate the effects of market fluctuations, our analyses show gross margin trends paralleling the yield improvements. Average first wheat margins have increased by around £25/ha since 2001 with second wheat margins going up by around £50/ha. So while second wheats were generating margins of £75/ha less than first wheats five years ago, the gap is now little more than £50/ha.

"This is hugely encouraging," he observes. "It is a great reward for the efforts our growers and their agronomists have been putting in to raise second wheat performance in recent years. And it underlines our long-standing belief that the performance of second wheats can be brought closer to that of first wheats with the right approach."

To what particular second wheat improvements then does Nick Myers attribute the shrinking performance gap ?

Well, he believes, it is certainly no coincidence that 2001 saw the introduction of the first-ever specialist take-all seed dressing, Latitude (silthiofam). Nor that a significant extension of Recommended List trials on second wheats in recent years has given growers far better information on which to base variety choice.

"Until five years ago the only defence against take-all was to delay drilling until mid-October," recalls Nick Myers. "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 Latitude, though, shone a fresh light on the problem. The take-all seed dressing 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.

"What the availability of an effective take-all treatment really did, though, was change attitudes. Now growers could seriously begin thinking about cutting the second wheat performance gap. And as they did so they started seeing second wheat as a distinctly different crop. 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 better second wheat growers outperforming our average first wheat growers by more than 0.65 t/ha last year and earning gross margins of nearly £55/ha more, there clearly remains considerable room for further improvement on many units."