Abstracted from an article in Wired Magazine:
The testing ground for the Italian experiment is a postcard-worthy, 24-acre Tuscan winery called Il Paradiso di Frassina.
In 2006, the researchers set up speakers in front of young plants in wooden tubs and older plants in a small vineyard on an isolated area of the estate. Shoots and tendrils exposed to this sonic fertilizer were tested once a week from May until December, when the plants go dormant.
They examined, among other variables, chlorophyll and nitrate content with a handheld Konica Minolta Spad-502 meter; photosynthetic and transpiration rates were checked with a Ciras-I infrared gas analyzer.
“Sound exposure has some positive effects on vine growth in the vineyard, especially shoot growth,” says lead researcher Stefano Mancuso, a professor of agriculture at the University of Florence. “The results aren’t conclusive yet, but total leaf area per vine was always higher in sound-treated vines, both in the vineyard and in the pots. The silent control pot-grown vines also showed delayed development.”
This was also reported in the Sydney Morning Herald.
Since the 1950s, researchers have been conducting formal and informal experiments on music’s effects on plants. Although there have been a few null-results or negative results, the vast majority of studies report that plant growth is significantly enhanced by classical music. The music in this vineyard is played at a very low level, so clearly the volume isn’t a factor, and it’s turned up for human visitors. So at least for plants, not only does classical music not have to be loud enough to hear for the music to affect them, it’s clear that one doesn’t even have to have ears!