Michael Pollitt, agricultural editorA large-scale survey of a major pest problem for beet growers is to be carried out this summer.The British Beet Growers' Research Organisation aims to assess the extent of beet cyst nematode, which is already recognised to be a long-term problem in many lighter soils.Michael Pollitt, agricultural editor

A large-scale survey of a major pest problem for beet growers is to be carried out this summer.

The British Beet Growers' Research Organisation aims to assess the extent of beet cyst nematode, which is already recognised to be a long-term problem in many lighter soils.

While it has been known for 80 years on the edge of Breckland and around Feltwell and further afield, it has come to light in west and North Norfolk.

A new variety on the 2011 Recommended List for sugar beet has been bred with resistance to rhizomania or sugar beet madness and also tolerance to BCN.

Richard Powell, of Hilleshog, said that Sentinel could deliver yield increases of 85pc in seriously infected patches of BCN.

Lessons from Sweden had shown the extent of the BCN problem where this season, 45pc of the acreage was so-called double-tolerant varieties.

In Sweden, where Hilleshog employs about 250 staff in research and development at Lanskrona, an estimated 30pc of beet land exceeded a guideline threshold of 1 egg/larva per gram of dry soil for BCN.

Mr Powell warned: "BCN is not easy to spot at lower levels of infestation. You could consider growing a strip of Sentinel across an infected field to see the difference that will show the presence of nematodes. With virtually no yield penalty on uninfected land this is an economic way to find out."

Trials at Feltwell had been carried out last year to look at the impact of growing on BCN-infected soil.

"When there is visibly no nematode infection, we're still getting an eight per cent yield advantage. In a hot spot, against the leading control rhizo-tolerant, that got arguably taken apart.

"Its yield was reduced to 37.5 tonnes per ha and Sentinel was yielding 85pc more under a high level of infection. If you built that into a whole field scenario, we still have a 28pc yield advantage worth �400 per ha.

"Sentinel is an ugly variety and is the best looking beet variety but it yields like stink.

"It is a case of telling the grower to let the harvester decide.

"Some growers know they have had it - it has been problem for 80 years but it is building up and at last there is something that we can do about it," said Mr Powell.