There's a phrase in German for those who react too quickly to new information - they "can hear the grass growing." But perhaps they merely have good ears.
A team of researchers under Douglas Cook at New York University have now made the growing of corn - a type of sweet grass - a "hearable" phenomenon in an attempt to better understand the micro processes and "breaks" in the structure of the corn shaft as it grows. The findings are meant to help reduce the destruction of corn stalks due to wind breakage.
At a meeting of the Acoustical Society of America (ASA) in Honolulu, Cook reported that when corn grows, it sounds almost identical to the sound of it breaking.
"We now think that plant growth involves millions of tiny breakage events, and that these breakage events trigger the plant to rush to 'repair' the broken regions," Cook said. "By continuously breaking and repairing, the plant is able to grow taller and taller."
The constant breaking and repairing of the stalk leads to the plant's growing taller and taller, just as repeated stress muscle training leads to aches and then growth.
Corn, which is produced in the US at a rate of nearly one million tons per day, is the most important domestic cereal. But the lanky crop is also vulnerable to wind breakage.
Scientists therefore approached the problem using methods like those in the field of structural engineering during materials research.
"Material breakage is a lot like a microscopic earthquake - the sudden release of internal stresses sends sound waves radiating in every direction," says Cook. The waves were measured by researchers with piezoelectric contact microphones.
In measuring the process researchers found, for example, that the leaves of the plants contribute particularly toward the stability of the plant during periods of rapid stalk growth.
Should plant breeders succeed in developing new corn types with more robust leaves, they might also help the plant survive strong gusts of wind.