Fields across East Anglia have blossomed into a vivid yellow hue in the recent warm weather, as this year's oilseed rape shows its colours.

The crop has become an important part of the region's farming rotations in recent years, providing the raw material for high quality cooking oils and animal feed.

But this year there is less of it being grown in England, according to information compiled by the AHDB (Agriculture and Horticulture Development Board).

A survey of more than 1,300 growers aimed to estimate the amount of winter oilseed rape (WOSR) lost due to damage from cabbage stem flea beetle (CSFB), a pest which had previously been controlled by neonicotinoid seed treatments – now banned due to suspected harmful effect on bees.

About 11pc of respondents said they would have planted additional areas of WOSR if neonicotinoid seed treatments had been available, and 5pc of the area originally planted was reported to have been lost to adult CSFB.

About 1.5pc of this area was reported to have been successfully replanted and the remaining 3.5pc was estimated to be equivalent to 22,000ha lost in England.

The survey estimated the national WOSR area to be 633,000 hectares on December 1, representing a small drop of about 1pc from the total area of oilseed rape – both winter and spring varieties – harvested in 2014.

Tim Issac, east regional manager for the HGCA (Home-Grown Cereals Authority), said: 'According to the latest survey results, we estimate that if neonicotinoid seed treatments had been available, the area that might have been planted would have been equivalent to a 5pc increase over the area harvested in 2014.'

The estimated losses are slightly higher than those reported in the HGCA-funded 'snapshot assessment' at the end of September, when the crop loss estimate was 2.7pc (18,000ha). The report showed wide regional variations, with the worst-affected areas in Hampshire, Bedfordshire and Hertfordshire.

Has your oilseed rape crop been affected by cabbage stem flea beetle? Contact chris.hill@archant.co.uk