In every Iowa cornfield, there’s a lot going on. You just need to know where to look.
Of course, it might also help to have an Iowa State University Field Agronomist like Mark Johnson along. Johnson says there’s no shortage of information, even in just a single corn plant.
“This is the mesocotyl,” says Johnson after digging up a representative plant. He’s pointing to a stem-like tube running from the below-ground seed to the above-ground plant. “You want that to be really nice and healthy white.”
The plant Johnson is holding has some slight deterioration on its mesocotyl: not a good sign. “Now, we’re getting close to V6,” Johnson explains, “So it’s not crucial, but if that started happening at V2, we’d be a little concerned.”
One possible cause for concern is pathogens in the soil. Johnson says that’s where seed treatments come in, and that’s why sometimes you’ll see green or pink seeds.
V1 and V6 refer to the plant’s vegetative stages, which begin with VE or emergence and end with VT or tasseling. Between those stages, the plant has up to about 22 other vegetative stages, depending on the hybrid, from V1 through V22, all referring to the number of collared leaves.
Based on that metric, the plant Johnson dug up is at the V4 stage.