Climate change could alter the face of apple growing in Britain03 October 2018
The home production of internationally-bred apples favoured by UK consumers might be increased in Britain in future due to climate change.
A warmer UK climate has already resulted in earlier apple flowering and harvest, and is enabling late-ripening apple varieties to be produced across more of the UK. Now, one of the largest climate change crop impacts experiments in the UK is beginning at Brogdale Farm in Kent, funded by the National Fruit Collections Trust.
It seeks to learn how warmer temperatures and altered rainfall patterns, expected in future decades, will affect UK apple production - potentially allowing popular international varieties like Granny Smith (Australia) or Golden Delicious (West Virginia, US) to be grown more widely in Britain and increasing UK growers’ share of the UK apple market.
Professor Paul Hadley of the University of Reading, and an NFCT Trustee, said: “Climate change is affecting top fruit already, but this is given less attention by researchers than annual crops. Our data shows that apple varieties are now flowering on average 17 days earlier each spring than 60 years ago.
“There are pros and cons to changes to apple flowering and harvest times, but these are likely to change the face of apple growing and lead to different varieties of UK fruit on supermarket shelves in the UK. This research will enable both professional growers and gardeners to learn how to adapt production techniques to cope with possible changes in the climate, and also identify varieties which are suitable for the UK’s future climate.”
Experiments at the National Fruit Collection, at Brogdale Farm near Faversham, are taking place in a new 0.6 hectare facility under polythene covers. Trees of more than 15 varieties of apple were established in 2014 and have been grown in modified environments since last winter. Traditional UK, such as Cox’s Orange Pippin and Bramley, and newer international varieties, such as Fuji, Gala and Golden Delicious, are included in the study. The experiments are planned to continue for at least a decade to monitor long-term changes and factor in year-to-year variation in ambient temperatures.
Some apples are grown under ambient conditions, while others are grown in climates either 2°C or 4°C warmer to simulate future warmer UK climates. Each is split with sprinklers providing actual rainfall, or 20% more or 20% less, to simulate changing weather patterns expected due to climate change.
The varying conditions produce diverse flowering and harvest times, as well as growth habits and winter chill requirement. Earlier blossom and harvest times may affect fruit quality and storage potential, but how significant these changes will be is not yet known.
Tim Biddlecombe, of the Fruit Advisory Service Team and Secretary to the National Fruit Collections Trust, said: “Over the last 20 years, growers have been adapting to earlier seasons, but it is important to understand the implications if this trend continues. Obvious changes like earlier flowering could increase the risk of damage from frost during blossom, while earlier harvest would provide English apples to consumers earlier in the year and so extend the marketing period for UK apples.
“English-grown Gala apples are valued for their colour, texture, and taste. Earlier harvest from a warmer climate could result in poorer colour development because this depends on a wide difference in day and night temperatures in the two to three weeks before harvest. Wide differences are much less likely in late August than in September when Gala are normally picked at the moment. High-temperature stress during late summer can also affect ripening rate and reduce fruit firmness, texture, and eating quality.”
Professor Richard Ellis, of the University of Reading and an NFCT Trustee, said: "Most research focuses on the short-term, but perennial crop growers, particularly of orchard fruits like apples, require greater advance knowledge of future climate impacts because variety and growing decisions are only changed when orchards are replanted every 15-20 years.
“The commitment of the National Fruit Collections Trust to initiate this long-term study is therefore remarkable. The vision is to expand the study to look at how different climates may affect the impact of pests and diseases. We are seeking further donors to enable this unique and exciting long-term vision to be realised.”
The new research facility at the National Fruit Collection, Brogdale Farm, near Faversham, Kent, will be opened formally by Helen Whately, MP for Faversham and Mid-Kent on 13 October.