Research on plant spacing variation is mixed. Some recent research indicates that as plant spacing variation increases grain yield decreases by one bushel per inch of standard deviation above two inches. Other research indicates that grain yield decreases at similar rates, but the critical threshold is above 5 inches. Stands that have that much deviation would obviously be noticed by growers and repair and maintenance of the planter would occur.
For more information on this or other topics related to corn production, contact your state extension corn specialist or your local extension educator/agent.
The following is the link to the corn extension specialists: state extension corn specialist
