A field of young sugar beet plants growing on a Norfolk farm last spring could easily have been mistaken for a land art installation, as blue and red rectangles decorated the plot.

In fact, it was a trial of a novel way of protecting crops from insect pests, known as ‘camo-cropping’. This is just one of a vast range of non-chemical methods now being tested, or used, as an alternative to toxic pesticides such as neonicotinoids. New approaches are needed as use of these pesticides is being increasingly restricted around the world for environmental reasons.

Camo-cropping involves spraying non-toxic fabric or food dyes on the field — covering the soil and the young plants — so as to reduce the colour difference between the bare earth and beet leaves. Aphids rely partly on this colour contrast to home in on crops. And these insects can be a devastating pest for beet growers, not because they eat the leaves but because they transmit a group of plant pathogens called virus yellows.