When it comes to water, some plants are picky drinkers. For example, grapes grown for the premium cabernet and merlot varieties require very precise amount of water to produce fruit of just the right sweetness. But modern measurements of plant water levels are far from ideal, says Alan Lakso, a professor at Cornell University who has been studying plant physiology for 40 years. Most commercial methods measure water levels by placing moisture readers in soil. But grapevine and apple tree roots like to travel — they can sprawl far from the reader location and skew the picture.
“They all measure water in the soil which is sort of indirect, because you’re not harvesting the soil,” Lakso says. “You are harvesting the plant.”
Measuring water levels inside the plant itself is a more accurate way to do it, but it’s a manual, labor-intensive process. Measurers cut off a leaf, place it into a pressure chamber and apply pressure to it until water comes out of the severed trimming. Because the method is time-consuming and slow, growers don’t use it often. Neither does it provide a continuous picture of the plant’s health, Lakso says, likening the process to taking a blood pressure on a patient once a week. “It tells you what it is, but it doesn’t tell what it was the week before,” Lakso says. “I wanted to have a way of monitoring plants continuously.”
To measure plant water levels continuously, every plant has to be equipped with its own personal water sensor — and that’s exactly what the Cornell team went for.
So he went inside the plant, “Fantastic Voyage” style. Read Full Story