Understanding Blackberries at New Covent Garden Market was organised by fruit plant nursery and researcher Hargreaves Plants.
The company's head of blackberry research, Jane Fairlie, presented the results of a collaboration between Hargreaves and Professor John Clark of the US University of Arkansas to breed sweeter primocane varieties.
"They fruit on this year's canes, which are upright rather than trailing, and are sweet enough to eat straight from the punnet," she declared.
"People say that black berries taste best straight from a hedgerow, but an independent tasting panel put primocane varieties ahead of both wild fruit and established varieties," she explained.
She added that the popularity of blackberries was growing fast, and starting to catch up on that of blueberries as their health benefits become similarly appreciated.
"There has been a fivefold increase in demand since 2005," she said.