Favourable weather conditions throughout 2011 and plentiful supplies have made potatoes as cheap as chips in recent months. But this could be about to change, as the recent heavy rain and flooding have delayed planting of the UK’s main potato crop and are slowing down lifting.

Last year was a particularly good year for the main potato crops of the UK and most of Western Europe. Planting in 2011 was helped by a dry start to the year and the weather held up, delivering dry conditions at the right time and excellent rainfall later to produce an unusally large crop. Overall, North Western Europe produced 26.6m tonnes of potatoes - 11% more than in 2010.

As a result, potato prices on the UK wholesale markets are, on average, currently trading at well below their five-year seasonal norm, with prices at £114/tonne compared with average prices of £146/tonne.

Wholesale prices 5 May 2012: plastics

Soaring naphtha prices and technical problems at some EU producers, which resulted in supply shortages in March, continue to take their toll on plastics. Lower demand over Easter temporarily eased the market, but many producers are still operating at reduced capacity, keeping supplies tight and prices elevated.

At £1,328.8/t, HDPE is 6.1% more expensive than last year, having moved up by 6.6% in the past month. LDPE film prices have also risen month-on-month, but remains 7.1% cheaper on last year.

High coconut oil prices in the Philippines recently drove buyers to opt for cheaper palm kernel oil, increasing available supplies, so prices have fallen by 11.9% in the past month and 28.8% year-on-year.

Prices have remained low despite the recent deluge because stocks from 2011 are still tiding us over. Last year’s main crop potatoes have kept well in cold stores, so there are still plenty of UK potatoes available and quality is good.

But these don’t last forever, and main crops - including King Edward, Maris Piper and Desiree - are not suitable for all uses. Early or new potatoes, for example, do not store well, meaning buyers have to rely on a good early season every year.

This is where the heavy rains are starting to make an impact, delaying lifting of new potatoes in early May. More worrying for the wider potato market is the fact that rains and floods have delayed main crop planting, with total plantings currently estimated to run to just over 70,000ha compared with almost 100,000ha this time last year and 75,000ha in 2010.

With the weather showing little sign of settling, the days of cheap-as-chips spuds could soon be over.