Climate change and more extreme weather events will add to the challenges and unpredictability faced by growers in the years ahead, Lancaster University Environment Centre professor Bill Davies told the fruiterers conference.
"We are already having to deal with the changes mapped out in Beddington's report six years ago. Climate change is happening and we will reach tipping points in some variables such as ocean currents, which will have cataclysmic effects on climate. There are more people to feed and they want to eat different things. The consequences of this are beginning to dawn."
He warned: "We should be very concerned about a global temperature rise of two degrees or more, though the consequences for crops aren't straightforward - for example, precipitation. Higher CO2 levels increase yields of major crops, but pests love high-CO2 crops so those problems will increase. Meanwhile, tropospheric (near-ground level) ozone is also increasing and crops don't like it. However, we are making massive strides in my own area of abiotic plant stresses."
Davies highlighted the work of Dr Mark Else at East Malling Research (now NIAB-EMR) on precision irrigation, which he said "has all sorts of benefits through the supply chain", adding: "The same thing can be extended to fertiliser."
Giving the keynote address, National Fruit Show president Michael Jack said this only adds to the various forms of "turbulence" that growers have to deal with now and in the future. "Retail turbulence stems from price and political turbulence brought on by an oil spike 10 years ago and hasn't stopped yet," he said.
"The next five years will see a reduction in consumer spending power. The retailers understand that so will continue to attract them using pricing, meaning continued pressure on margins. You can't avoid this but you can plan for it."
Meanwhile, he added: "There are export markets out there to go for, thanks to a growing middle class. Africa's population will double in the next 30 years. Turbulence is here to stay but we can deal with it in a positive way."
On Brexit, Jack said: "We won't be able to answer what it means until after the French and German elections and the Treasury reveals how much money it will put into agriculture. We export £18bn of food but £32bn comes in. No one knows what will happen to this.
He added: "We have to do a Brexit audit, on the law on chemicals, the environment, logistics, health and safety. If these are impacted, how do we deal with that? What if your company brings produce in from Spain and suddenly that takes three or four hours to clear the ports? Our strategy should be: 'How do we become the most risk-proof industry?'
"We need good science but presenting that to the public can be difficult. Leaving the EU is an opportunity here but we have to take the public with us."
Produce World director of agriculture Andrew Burgess wondered: "What will post-Brexit support go on? Research and development? Upland farming? These are big questions." On the relative merits of responding to agronomic pressures with production shifts compared to varietal development, he said: "It has to be a multi-pronged approach."
Davies added: "Pests and diseases are moving as the climate changes and we should be concerned. But varietal development shows great promise. Modern glasshouse salad growers use integrated pest management and it has to be pretty bad before they use chemicals. New systems for growing like urban farming are part of the answer."