The area planted with oilseed rape (OSR) has been forecast to fall to its lowest figure for 13 years – with a particularly steep decline in the East of England.

Results from the Early Bird Survey published by the Agriculture and Horticulture Development Board (AHDB), predicts the 2017 OSR area at 557,000ha, down 4pc compared with Defra's estimate for 2016.

Millie Askew, AHDB cereals and oilseeds analyst, said: 'If realised, this would be the fifth consecutive fall in the OSR area, but it's expected that there will be key regional differences. For instance, there has been a dramatic decrease in the east of the country, a 28pc decline attributed to cabbage stem flea beetle damages, and a lack of moisture which made establishment very difficult. In other areas of the country - the Midlands, south and Scotland - however, the area sown to oilseed rape has increased.'

Meanwhile, the wheat area is predicted to fall 1pc against the previous year to 1.8m hectares, with grass weed challenges expected to be the main limiting factor on many farms.

Following the trend of recent years, the area planted to spring barley continues to rise, and is predicted to be 17pc higher for harvest 2017 than harvest 2016, at 799,000ha.

Ms Askew said: 'The survey suggests that this increase is in areas most affected by black-grass. But some farmers will also have been influenced by poor winter barley yields for 2016. However, it is possible that if the price of wheat continues to rise above barley, some of this area could be sown to spring wheat instead of barley.'

Data for the Early Bird Survey is taken from 262,500ha arable land across Great Britain, and was carried out by the Andersons Centre and the Association of Independent Crop Consultants (AICC).

The AHDB pointed out the survey only represents a snapshot of actual plantings and more tentative intentions, so factors such as weather, cultural controls and potential crop margins could still impact on whether the surveyed spring planting intentions are realised.