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Have you ever noticed a difference in humidity in vegetation? It's called "Corn Sweat" | Hey Ray!

Hey Ray: Corn Sweat
Hey Ray: Corn Sweat 02:25

PITTSBURGH (KDKA) - Summertime is full of heat and humidity. Usually, the combination of the two makes for a very steamy situation. You may have noticed though, that in the hotter parts of the year, when you're out and about it feels much more humid and steamy when you walk from low vegetation to higher vegetation.

So why does this happen? 

Well, the non-scientific name of this phenomenon is "corn sweat." Yep. So people call it "corn sweat."

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Notice that moisture when you're walking through the corn?  Getty Images

Since this has to deal will all vegetation, we'll mainly call this process by its scientific name of "transpiration." 

It is the evaporation of moisture that comes from plants. All plants, not just corn. Corn is very efficient at this process though. Since it is most prevalent when the corn is knee high and higher, corn sort of gets the bad wrap, even though all vegetation takes part in this process.

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It's not just the corn that takes part in this process - it's all the vegetation.  Ray Petelin

When the roots of a plant take in water from the soil, that moisture moves through the plant to help it grow and stay alive. The water is eventually released through the leaves.

You can't really see this process happening, but plants can give off a lot of water. I mean A LOT!

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Plants give off a lot of water! Ray Petelin

Plants give off many more times their own weight in water. The United States Geological Survey says an acre of corn gives off 3,000 to 4,000 gallons of water each day! A large oak tree can transpire 40,000 gallons of water in a year.

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Well hey...that's a lot of water! Ray Petelin

Transpiration just accounts for the moisture passing through the plants!

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All that water helps everything! Ray Petelin

Transpiration gets added to all the other moisture that is released into the atmosphere from groundwater, soil, bodies of water and everywhere else through evaporation. When you add up all the evaporation and the transpiration the sum of what you get what is called evapotranspiration. Evaporation and transpiration work together, making things feel hotter.

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We may call it "corn sweat" but it's really evapotranspiration!  Ray Petelin

So, we have corn sweat, but there isn't yet corn deodorant!

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