Growing sweet corn at higher densities doesn’t increase root lodging risk

by Lauren Quinn, University of Illinois at Urbana-Champaign

Sweet corn growers and processors could be bringing in more profits by exploiting natural density tolerance traits in certain hybrids. That’s according to 2019 research from USDA Agricultural Research Service (ARS) and University of Illinois scientists.

But since root systems get smaller as plant density goes up, some in the industry are concerned about the risk of root lodging with greater sweet corn density. New research says those concerns are unjustified.

“Root lodging can certainly be a problem for sweet corn, but not because of plant density. What really matters is the specific hybrid and the environment, those major rainfall and wind events that set up conditions for root structural failure,” says Marty Williams, USDA-ARS ecologist, affiliate professor in the Department of Crop Sciences at Illinois, and author on a new study in Crop Science.

Williams and his co-authors used multiple approaches to understand the effects of planting density on root lodging in sweet corn. First, they planted sweet corn hybrid DMC 21-84—a density-tolerant type that happens to be one of the most widely grown commercial hybrids—at five densities in experimental plots on U of I farms. When plants were at the tasseling stage, the researchers simulated a natural lodging event by flooding the field and knocking the corn over with a two-by-four.

“We mimicked a root lodging event with pure brute force,” Williams says.

When corn is flattened in the process of root lodging, it can, depending on the growth stage, right itself through the plant’s natural inclination to grow toward the light. As corn grows back upward from its repose, the base of the stem often carries a curved reminder of its lodging legacy, known as a gooseneck.

Williams and his team found most plants recovered to a near vertical position, albeit with a bit of goosenecking, within a few days of the artificial lodging event. They also measured yield metrics, and found no statistical difference in sweet corn yield between lodged and non-lodged plants.

But a two-by-four and brute force can’t replace nature.

“Testing a crop’s root lodging potential experimentally is inherently difficult. Simply put, a natural root lodging event may not happen in any given field experiment. As such, phenotyping crops for root lodging often employs the use of artificially created lodging events, like the ones we created,” Williams says. “While artificially created root lodging events are helpful, used alone they often fail to capture a broad range of environments in which the crop is grown.”

> Source: PHYS.ORG