There are views aplenty, mainly driven by soil type, over the realism of British Sugar’s target yield of 70t/ha (28t/acre) within four years.

The national average last year was just over 60t/ha (24t/acre), notes Mr May.

“I suspect most growers can achieve another 5t/ha by more attention to detail, better harvest scheduling, better varieties and climate change and by not cropping poor field areas.”

However the BS target is hard to aim for with year-to-year consistency on thin, light soils such as the Brecklands, says Dr Turnbull.

For Mr Oldfield, whose five-year adjusted output average off sandy loam is only 56t/ha (22.5t/acre) says it is “totally unrealistic”.

For his land 60t/ha (24t/acre) is a more sensible aim, he believes.

The 70t/ha can only be a long-term goal, says Mr Ireland.

“Our soil type does not have the potential year in year out to yield that, mainly due to moisture problems.”

Former Barometer grower Tim Hardstaff’s sandland in Nottinghamshire averages 57t/ha (23t/acre).

“The BS target is realistic, but only in 10 years’ time, not five.”

“Our average is 65t/ha,” says Norfolk Farmer Focus writer Chris Harrold.

“But we’ve had some good beet years and don’t have to go back too far to put together a three-year average at 60t/ha.

“Assuming the current weather pattern continues, then with new varieties, better techniques and management maybe the top 25% can make it.”

But growers in mid-Norfolk, currently with yields in the 50s, have little room for improvement, he believes.

“Their soils are unstable and they rely on ideal conditions to get 60t/ha.”

However, Mr Young, already averaging 65t/ha (26t/acre) on his organic soils, believes 70t/ha over the next five years is “quite realistic.”

Eastern Barometer grower John Barrett also thinks better management, more fungicide and earlier drilling should help him get there from his present 56t/ha (23t/acre) mean.

Norfolk’s Robert Hambidge points out that he lifts for growers who are already above the BS target “by a considerable margin”.

“Of course it’s realistic.”

But early harvesting on his light land before full potential has been realised will be dropped.

“I don’t propose lifting early any more when the yield is perhaps 45t/ha.”