Wet, windy weather, sometimes marked by hail in the central Plains may have some corn growers wondering if stand loss means they should replant their crop, a Kansas State University agronomist said.
Stand loss in corn usually causes relatively little yield loss, at least at populations greater than 24,000 plants per acre, says Kraig Roozeboom, K-State Research and Extension crop production specialist. The amount of yield reduction from stand loss depends on the stage of growth, he adds.
Research by Barney Gordon at K-State's North Central Experiment Field near Belleville evaluated the effect of stand loss on yields, ear number, and ear size by removing plants at various stages of growth. This study showed that:
* Yield loss was much less than stand loss at every growth stage.
* Yield loss was greater when stand losses occurred at later growth stages.
* Ear number per plant increased slightly at 50% stand loss, and more at 75% stand loss.
* Seed weight did not change as a result of stand loss.
* Ear size increased with greater stand loss at early stages of growth.
When a producer is considering replanting due to poor stands, they should keep in mind that planting corn in early June in much of Kansas can result in yield losses of up to 50% compared to a typical planting date, Roozeboom says.
"It would probably be better to keep an existing stand even with as much as 30-40% stand loss than to replant in early June in most of Kansas. Of course, much depends on the actual number of plants remaining, uniformity of the remaining stand, and the weather for the rest of the growing season," he says.