How to correctly measure corn height

Many corn herbicide labels will give both a growth stage and height in inches (whichever comes first) as to the latest point an herbicide can be applied. An example: Armezon PRO can be applied up to V8 or 30" corn (whichever comes first.) There have been some misconceptions on how to properly measure a corn plant. The biggest misconception is to measure the highest point on the plant- that is NOT the correct way. The proper way to determine a corn plant height is to measure from the soil surface to the highest point of the arch of the leaf that has the last visible collar, such as shown in the picture below. Please note, with the stresses out there this year, corn may not be at its normal height for where we would expect it to be at for a growth stage. Due to this, it's important to count leaf collars as well rather than just go off plant height.This corn plant is at V5 and has a height of 7 inches.