I’m inconsistent at times when watering my plants. Now, however, I think I’ll reform. Researchers in Israel report that stressed tomato and tobacco plants, whether from dehydration or having their stems severed, emit sounds comparable in volume to normal human conversation. The emissions are too high for our ears to detect, but insects, other mammals, and plants can likely hear them.
Microphones recorded healthy and stressed tomato and tobacco plants, first in a soundproofed acoustic chamber and then in a noisier greenhouse environment. They then stressed the plants by not watering them for several days or cutting their stems. The researchers trained a machine-learning algorithm to differentiate between unstressed, thirsty, and trimmed plants. Stressed plants emit more sounds than unstressed plants. The plant sounds resemble pops or clicks at a rate of 30–50 clicks per hour at seemingly random intervals that we can detect over a meter away. Unstressed plants emit far fewer sounds.
A machine-learning algorithm could accurately differentiate between stress from dehydration and cutting and could also discern whether the sounds came from a tomato or tobacco plant.
Growers can use sound recordings of plants in agricultural irrigation systems to monitor crop hydration status and distribute water more efficiently.
