A huddle of people are clustered around a few thorny durians. A fruit is picked up and assessed – first it is shaken, then hands are appraisingly clamped on the spiky exterior. Finally, an intrepid nose hovers inches away from the fruit’s sharp carapace.

“Not enough nutrients,” pronounces durian expert Lim Chin Khee solemnly. “Look at the black spots here – it shows a lack of calcium,” says Lim prodding a darker area surrounding the thorns on the fruit.