THE wettest summer for 100 years has resulted in England producing its lowest wheat yields since the 1980s.

The NFU 2012 harvest survey shows overall wheat yields fell by 14.1 per cent on the five-year average, down from 7.8 to 6.7 tonnes per hectare.

The area planted was up from 1.916m/ha to 1.988m/ha but, because of the weather, estimated production has fallen from 14.916m/t to 13.250m/t.

Guy Gagen, NFU chief combinable crops adviser, said yields could have been even worse if farmers had not invested in technology.

He said: “Investments in grain drying and handling facilities have been vital, while improved combine harvester capacity meant significant progress was made when breaks in the weather allowed. Although 2012 may be a harvest to forget for many, it has underlined the need for continual investment in agriculture.”

The survey revealed mixed results among the main arable crops, with average results hiding extreme variations across the country.

Mr Gagen said: “Yields for some crops have performed better than average in 2012 with results for barley reported as good for malting and around average for rapeseed in terms of oil content and yield.

“Much of the 2013 rapeseed crop is now planted and farmers will be looking for further breaks in the weather to complete winter cereal crop planting.”

The poor UK harvest conditions coupled with droughts in North America, a heatwave in Russia and challenging weather in other countries had pushed up agricultural commodity prices around the world “Cereal prices impact directly on other sectors, especially pig and poultry farmers who are already struggling with higher feed costs,” he said.

Commenting on the knock-on impact on poultry farmers, Tom Hind, NFU director of corporate affairs, said recent volatility in feed costs had been unprecedented and likely to stay.

“Feed is the single biggest cost to poultry producers and many are reporting to me the significant outlay they are having to make to purchase feed compared to last year,” he said.

“It’s now really vital that the whole UK supply chain works together to ensure these additional costs farmers are facing are recognised or else we see a risk of critical mass in domestic production eroding.”

The NFU survey also found winter barley yields to be up 1.6 per cent on the five-year average, from 6.3 tonnes to 6.4 t/ha. The area grown rose by 0.5 per cent to 391,000 ha and estimated production was up 0.6 per cent, from 2.472m/t to 2.486m/t.

Spring barley yields were down 7.4 per cent on the five-year average, from 5.4 to five tonnes per hectare. The area was down 1.2 per cent on the five-year average – from 604,000ha to 597,000ha – and estimated production down 9.1 per cent, from 3.255m/t to 2.958m/t.

Oilseed rape yields were up 5.9 per cent on five-year average, from 3.4 to 3.6t/ha. The area was up 18.6 per cent from 639,000ha to 758,000ha, with estimated production up 25.5 per cent on five-year average, from2.196m/t to 2.755m/t.

The British Retail Consortium has warned the impact of the weather, particularly on wheat, is likely to see rises in the cost of food.