Later Drillings May Necessitate a Variety Switch Says Consultant

Mike Jeffes

According to variety consultant, Mike Jeffes later drilling generally leads to shorter crops and reduced lodging risks, as well as lower disease concerns. In addition, milling wheat growers can benefit from reduced protein dilution and there may be opportunities to use glyphosate to clear up problem blackgrass.

However, trials show that from mid-October onwards yields can drop by over 1t/ha compared to optimum mid-September timings, so it is important to pick the right variety for the later drilled slot.

On analysis from Recommended List late drilled trials, he confirms that Conqueror is likely to give the highest yield, followed by Oakley.  “In truth though, there would be little to choose in yield terms between these front-runners and Ketchum, Viscount and JB-Diego,” he says.

Mr Jeffes points out that Viscount, KWS Sterling and Humber, of the KWS varieties, seem well adapted to both early and late sowing dates, although Oakley will still probably give a little more yield.

Varieties where the yield drop between early and late autumn drilling is on the high side include Claire and Grafton, along with, perhaps, Duxford, Zebedee and KWS Quartz, so here it may well pay to switch orders if you can.

Whatever variety that is selected, with later drilling comes a need to increase seed rate, as plants have less time to tiller in the autumn before growth closes down, and, depending on variety, there may be no extra time in the spring for additional tillering as stem extension is mainly driven by day length.

Mr Jeffes’ advice is to generally increase rates by 25 – 30 seeds per square metre for each week’s delay from those you’d normally use at the end of September.  “Clearly though, seedbed conditions and soil type will impact greatly on this decision.”