Many of you have at last some corn planted – some have all of it planted. How well did it emerge, and did it emerge evenly?
Those are questions Bob Nielsen, Purdue University Extension specialist, believe you owe it to yourself to answer. You won't know unless you make trips into the field as corn emerges. Waiting two weeks is too long. You may pick up differences in plant height still then. But it may not be as obvious as if you looked earlier.
Nielsen has done lots of work in the past, documenting possible yield loss to both poor plant spacing within the row and uneven emergence. Plants which emerge more than one leaf collar behind their immediate neighbors often end up like a weed, producing a nubbin at best. They compete for nutrients and moisture, but typically lose out on getting as much as they need.
What factors can delay some kernels from germinating at the same time as other kernels in the same row? Soil temperature is likely number one, agronomists say. If some kernels are deeper where soils are cooler, it could take longer for those seeds to germinate and emerge.
However, Indiana Prairie Farmer Tippecanoe County Extension plots conducted over three years show difference in yield from planting at 2, 3 or 4 inches deep.
Another factor that can affect even emergence is moisture. If it's on the dry side, as it was in the southern half of the state on some planting days earlier this month, the difference may lie on whether every seed is placed at the same depth, in the same amount of moisture as other seeds in the row. If some seeds are so shallow that moisture is limiting to started germination, emergence may not be as uniform as you like.
The only time in three years in the depth experiment there has been a significant difference in yield was during year one, when the surface dried out and the shallow, 1-inch planting did not emerge or grow evenly.
Continued reading: Corn depth: How deep do you plant?