The tough season has meant big losses for some potato growers, but others "have hit the jackpot", agronomy consultant Denis Buckley told the ADAS/Syngenta UK Potatoes Conference in Newark on 22 November.
"The net yield will be around 4.5 million tonnes, maybe even less, which is about in line with 1976 rather than the six-million tonnes we'd expect in a typical year," he said.
"Most growers have lost bits of fields to flooding and some have lost whole fields. They will be more careful about field selection in future. But yields are still down 15 per cent even where canopy has been retained, due to the dull weather."
However, within this gloomy overall picture lies a great deal of variability, he stressed. "We have never seem such variation in net returns, nor are we likely to again. Heavily contracted growers have been hit hardest, given the combination of low yields, moderate prices relative to the free market and lack of excess tonnage to buffer the contracts."
He added: "But there have been some real winners too. Growers who are selling now on the free market are enjoying a bonanza that has not been seen since 1995."
The main lesson from the season, he suggested, is that "the risks involved in potato growing are greater than we thought", adding: "A price of ú30 a tonne would be a reasonable figure to cover those risks. A force majeure clause in contracts would also give growers some safety in years like this."
But despite recent weather extremes, long-term trends show neither rainfall nor sunshine is trending up or down, though temperature has risen by one degree over the past 50 years, he added. "Climate change models are becoming less certain and more circumspect."
Blight Resistance still a stumbling block
Another lesson from 2012 is that "blight is still a disease to fear", Denis Buckley told the UK Potatoes Conference.
"You see a decline in a variety's blight resistance over time anyway. But with some new varieties we seem to be going backwards here. We will be on a treadmill of having to use more and more fungicide."
But he is sceptical that trials to develop blight resistance through genetic modification will prove to be the answer.
"It's all too easy to imagine a scenario where the national potato crop is dependent on a single source of blight resistance and were that to break down then blight would rip through the crop. Phytophthora has form when it comes to overcoming resistance genes."