Harvest Highlights Huge Second Wheat Variability

Second wheat performance is exceptionally variable across the country this harvest, reports Masstock agronomist, David Vine. Some crops have delivered a very healthy 4.2 t/acre (10.4 t/ha) while others have struggled to reach 2.4 t/acre (6 t/ha).

"We can normally rely on an average 3.5 t/acre (8.6 t/ha) from good heavy land second wheats in central England," he observed. "This year we're probably averaging under 3 t/acre (7.4 t/ha) on the same ground. And the overall range of second wheat yields is incredible - I'd certainly say double the normal variation.

"Very dry weather at establishment followed by a wet winter with a surprising amount of frost, six weeks of drought in the spring, and that incredibly hot summer spell has played havoc with rooting systems," pointed out David Vine.

"Take-all wasn't so obvious earlier on, but the roots of harvested second wheats, wheats after set aside and barley have shown us just how bad this season's take-all problem really was. And there's been plenty of fusarium about too, on both the stem-base and the ear.

"Not surprisingly, light land crops have suffered badly. Those sown before the third week in September, into min-till seedbeds or direct-drilled also appear to have come under particular pressure."

Under these conditions, take-all seed treatment and spring rolling have been the saving graces for a number of David Vine's crops. The specialist seed treatment, silthiofam has, indeed, helped one of his growers buck this year's trend, turning a normal 2.5 t/acre (6.2 t/ha) second wheat crop into an impressive 3.9 t/acre (9.6 t/ha) producer. Equally, rolling badly frost-lifted ground in the early spring has meant a difference of between 0.5 - 0.75 t/acre (1.2 - 1.9 t/ha) for several.

"Spring rolling has helped keep take-all infections at bay while improving rooting," he explained. "Many people haven't appreciated just how much frost we had last winter. But in some cases we saw wheat crops lifted almost out of the ground. This year has really highlighted the value of the roller - a piece of kit badly underrated by many in recent years.

"Latitude has proved a real star for us this season too. In our experience it's the only take-all treatment worth using, allowing drilling dates to be brought forward 7-10 days at no extra risk.

For the season ahead, David Vine advises growers to plan for another difficult take-all year, given the high levels of disease carryover likely from first wheat crops, set aside and barley. In particular, he recommends:

• Choosing a variety proven to perform in the second wheat slot - Option or Einstein as millers and Consort, Deben or Napier in the feed sector;
• Treating it with the specialist take-all fungicide, Latitude - together with a standard single-purpose seed dressing;
• Rolling in the spring if necessary as well as after sowing - to ensure consistently good season-long soil consolidation;
• Ensuring sufficient root-stimulating seedbed phosphate - on the basis of good soil sampling; and,
• Getting the first spring nitrogen on just as early as soil conditions allow.