They hope that farmers may eventually encourage plants to flower or ripen by blasting sound into the fields, the British weekly says in its next issue, due out on Saturday.

Mr Jeong Mi Jeong of the National Institute of Agricultural Biotechnology in Suwon and his colleagues explored a long-standing hypothesis that, as plants react to light and also to touch, they may also respond to sound.

The team set up rice plants in a laboratory and played them 14 pieces of classical music, including Beethoven's Moonlight Sonata, and monitored various genes to see whether there was any change in activity.

The music had no effect, but things changed when the researchers played the plants sounds at specific frequencies, New Scientist says.

Two genes, called rbcS and Ald, became more active at 125 and 250 hertz, and less active at 50 hertz.

Both genes are known to respond to light, so Mr Jeong's team checked what happened when the test was repeated in the dark - and found that the two genes still responded to the sound.

These genes could be used as sound-sensitive switches to turn on and off other genes that control key plant functions, the researchers hope.

Genes are segments of DNA, the molecular blueprints of cells. The way that a living organism develops is a result of its genes interacting with one another and with the environment.

The research appears in a specialist journal, Molecular Breeding.

It has been greeted sceptically by other specialists, who question the scale and methods of the experiment and the practicality of using sound in a rural setting, where wind would disrupt frequencies, New Scientist adds.

The institute is a government-backed research body that aims to manage South Korea's biological resources and develop them for practical use, the institute said on its website.

AGENCE FRANCE-PRESSE