Earlier Second Wheat Drilling Extends Performance Advantage

February 2004 - Using careful take-all management to bring second wheat drilling forward by around three weeks to mid-September improved yields and specific weights markedly for the second year in a row last season, according to comprehensive Allied Grain trials. What is more, both the yield and quality benefits were greater in 2003.

In the 2002 season the 12 varieties drilled as second wheats in the second week of September with the specialist take-all seed dressing, Latitude out-yielded controls drilled in the first week of October with a single-purpose seed dressing by an average of just over 0.5 t/ha. Despite apparently lower take-all levels across the site in 2003, the yield advantage of the take-all treated September sowing was increased to nearly 0.8 t/ha.

At the same time, the earlier-sown treated wheat recorded a 5.3 kg/hl specific weight advantage over the later sown untreated crop, as against the 1.7 kg/hl improvement seen in 2002.

Second Wheat Trials (Allied Grain, Haywold)

Year 2nd Week Sept Drilling 325 seeds/m2 with Latitude + single-purpose treatment) 1st Week Oct Drilling (350 seeds/m2 with single-purpose treatment) Latitude-treated Sept Drilling Advantage Yield Spec Wt Yield Spec Wt Yield Spec Wt 2002 11.73 t/ha 77.4 kg/hl 11.21 t/ha 75.7 kg/hl + 0.52 t/ha + 1.7 kg/hl 2003 11.14 t/ha 76.8 kg/hl 10.36 t/ha 71.5 kg/hl + 0.78 t/ha + 5.3 kg/hl

Reflecting the experience of many south-eastern growers, yields across the second wheat trials last year were noticeably lower than 2002. While the September-sown controls only produced 0.12 t/ha less than 2002, the October sowings were fully 0.85t/ha down.

Specific weights were also down across-the-board, with the October-sown controls at 4.2 kg/hl lower than 2002 particularly badly affected.

"Our October-sown second wheats seemed to be hit far harder by the challenging season than earlier drillings," explained Allied Grain trials and technical manager, Jim Carswell. "With rooting likely to have been restricted by the very wet October of 2002 and far less establishment time, they really suffered in the spring drought. And the scorching July cut short their later grain fill opportunity. This would have seriously compromised both yields and specific weights.

"Even though our root assessments recorded a late season surge in take-all infection, 2003 levels were markedly lower than the year before," he continued. "This allowed the inherent yield advantages of earlier sowing to be less badly eroded than usual by the disease, even in the absence of a specialist take-all seed dressing."

Under these conditions, the yield boost given to the September-sown wheats by Latitude (silthiofam) treatment in the trials was lower than the 1.17 t/ha recorded in 2002. The fact that it still averaged 0.7 t/ha, however, confirms the extent to which take-all continued to affect the season's crop.

"One of the really important messages emerging from our continuing series of annual trials is the consistent value of bringing second wheat sowing forward to September with good take-all protection, rather than relying on the conventional approach of take-all avoidance through delayed drilling," stressed Jim Carswell.

"In a bad take-all, but generally good growing year like 2001/2, early sowing Latitude-treated seed gave us a 0.52 t/ha yield and 1.7 kg/hl specific weight advantage over conventional practice. Equally, in a moderate take-all year like 2002/3 when challenging growing conditions really penalised later drillings, the same policy delivered a boost of 0.78 t/ha and 5.3 kg/hl respectively.

"With wheat at £75/t, the yield benefit from our early-drilled second wheat alone was worth nearly £60/ha last season. This was well over twice the cost of the take-all treatment, making it a particularly economic proposition.

"Our experience underlines the opportunities now available for increasing cereal yield and quality potential by bringing second wheat drilling forward as early as mid-September," he concluded. "Our results indicate that, as well as reducing the risk from take-all, the specialist seed treatment approach can also help reduce the risk of lower yield potential through poor crop establishment in later sown crops."