“We don’t know how bad, we just know it’s bad!” That’s the apparent expertise of those who blame corn for making all of us miserably sweaty this time of year. It’s a shoot first, aim later accusation.
There is no science that can accurately determine how much moisture corn ‘sweat’ will actually add to existing humidity on any given day. To smooth out that wrinkle, we’re told how many gallons of soil moisture corn could ‘sweat’ out of its leaves with the expectation that number applies when warm, humid air invades from the Gulf of Mexico. That expectation is actually counterintuitive.
We’ve all learned that a wet towel dries more slowly on a high humidity day compared to a low humidity day. We’ve also noted that our own sweat hangs around longer on a humid day. The same principle holds true for water evaporation from plant leaves. That’s because air that’s already saturated with moisture is less able to hold more moisture. In other words, as humidity increases, leaf evaporation decreases.
Every corn farmer has witnessed wilted (dehydrated) leaves in dry air and turgid (hydrated) leaves in humid air while all other conditions remain virtually unchanged. It’s the ‘smoking gun’ that proves corn prosecutors exaggerate.
Last mid-October we experienced a day of oppressive humidity. The midday radio meteorologist reported that it couldn’t be due to corn — the corn was all dead. Therein lies the hope that more people will learn to aim first, shoot later.