Bob Nielsen calls it the ugly duckling stage. It's when corn is small, maybe two to four leaves, maybe a bit yellowish. Things don't help if the weather is cool and wet, like it has been in part of the state over the past couple of weeks. But giving up on that corn could be a big mistake.
Nielsen, the Purdue University corn specialist, who likes to refer to the crop he researches as King Corn, says it can recover quickly. As he puts it in the May 14th Pest and Crop Newsletter, published by the Purdue University Entomology Department on -line, the 'ugly duckling' can become a beautiful swan' later in the season. That's assuming that warmer temperatures return, which is traditionally the case- sooner or later.
Others have referred to this stage, before corn reaches knee-high and the growth point gets above ground, even if it's not cool and wet, as the 'awkward young calf;' stage. The plants are slender, the full capacity of their roots haven't kicked in yet,. Especially if starter fertilizer wasn't applied, and there's far more bare soil than there is plant. The net effect is a rather disappointing look to a field of corn, kind of like a young animal looks when it's more legs than anything else. Then the growth spurt kicks in!
Corn can grow several inches per week in the V8 to V9 stage. We've even set up yardsticks in past years to measure how much corn grows in a week's time when it reaches this stage and kicked in the afterburners. The growth can be substantial, with plants covering up several inches of a ruler within a single week.
Waiting for that point takes patience. It's sort of like early no-tillers used to tell their landowners- yes, it looks ugly as the weeds die and the corn emerges. But just go on vacation and come back in a couple of weeks. It will look much better. Most no-tillers have learned the wisdom in doing so.
Nielsen expects it will be the same for farmers in any tillage system this time. The only problem may come if insects or disease actually thinned stands in certain spots in the field. If that happens, refer to the Purdue University Corn and Soybean pocket Field Guide for help in determining replant options. Be sure to check the tables that show what percent of optimum yield you would achieve replanting on the first possible date you can replant, vs. leaving the stand planted at an earlier date. Often, the thinner stand planted earlier still has a chance to reach a higher overall yield potential. It also has the advantage of no replanting costs.