In a groundbreaking study, Israeli researchers discovered that plants emit different ultrasonic sounds when they are stressed. The more stressed the plants are, the more sounds they emit.  Previous studies have shown that plants do vibrate when subjected to stressful conditions, and researchers at Tel Aviv University in Israel wanted to learn if these vibrations eventually become airborne sound waves. To check, the researchers grew tomato and tobacco plants inside an acoustic chamber and placed microphones between each plant.  The researchers discovered that each plant emits a specific sound depending on the type of stress they experienced. The detected sounds have frequencies between 20 and 250 kilohertz, which are inaudible to humans but can be heard by certain animals, such as bats and insects.  Plants also emit more sounds when they are more stressed, but the sound activity usually goes down after reaching a certain threshold, such as after being very dehydrated.  Through artificial intelligence (AI), the researchers were able to separate the nature of each sound and shared that the tomato and tobacco plants typically emit just one sound every hour if they are in the right conditions, but when subjected to stress, they usually emit dozens of sounds, and each sound is unique to each plant and each type of stress.  The discovery of ultrasonic sounds can soon be a useful way for farmers to better understand the condition of their plants. With AI-aided tools, the sounds can help plant growers increase their farm's efficiency. [Source](https://www.cbsnews.com/news/plants-emit-a-rather-noisy-cry-for-help-when-under-stress-scientists-find/) [Read more about farming and gardening at agriculture.com.ph](https://www.agriculture.com.ph/)