16 June 1995

Beet growers must work harder

SUGAR beet quota is set to fall by at least 2% over the coming five years and maybe as much as 5% (see page 53). So growers must work harder than ever to protect yield and quality.

That is the message to growers from a series of British Sugar meetings around the country.

Irrigation can give an instant and worthwhile response, yet many growers with irrigators fail to treat beet, says Mike Armstrong, head of agriculture R&D at British Sugar.

Rationed applications

On sandy loams at Gleadthorpe, Notts, ADAS has shown rationed applications which apply half the usual amount of water, but at the same timings as a scheduled system, can give a 3t/ha (1.2t/acre) sugar yield boost.

That was just 1t/ha (0.4t/acre) behind a full scheduled approach and well ahead of applying the same amount either early or late alone.

What is more the approach could be safer where rhizomania is a worry, avoiding excess applications which encourage symptoms, he adds. Amino-N impurities were also reduced with irrigation, from 220mg/100g to 163mg/100g in the trial. "For each 25mm of water applied this way you can expect an extra 4t/ha of beet."

With a 100% powdery mildew infection warning from Brooms Barn for the Ipswich area "everyone needs to spray". Use sulphur once symptoms appear in August, he urges. At £10/ha (£4/acre) the cost is more than covered by the typical 6t/ha (2.4t/acre) root yield response, even at C-beet prices. Yet only 28% of growers spray, despite 57% of the UK area typically being infected.

Rust and ramularia are not worth treating unless a belt lifter is being used or the tops are to be fed, Mr Armstrong claims. "Spraying Tilt or Radar maintains a greener leaf but it doesnt improve yield."

&#8226 Harvest and storage is a big concern for British Sugar. Field losses are typically 5.2t/ha (2t/acre). Better machine setting and operation could cut those to 2t/ha (0.8t/acre). With that in mind, BS fieldsmen will check crops at harvest to assess losses and advise on machine settings. "Each year 9% of the national crop stays in the field. We need to get that down," says Mr Armstrong.

Very fragile

Sugar losses from damage can also be cut. "Sugar beet is a very, very fragile vegetable, just like potatoes or carrots. But you cant see the sugar you are losing. You should handle the crop much more like potatoes." He suggests operating turbines as slowly as possible and reducing drop heights.

"An 8ft drop on to other beet loses 0.05% sugar. A 16ft drop loses 0.1%. Thats 1400t nationally. The same drops on to concrete or the trailer bottom lose 4000t of sugar. It simply oozes away."