On January 21, 2022, sorting out and releasing: as time goes on, the steady improvement of plant density tolerance has greatly promoted the increase of genetic yield of field maize. Although our recent research shows that the plant density tolerance of modern sweet corn hybrids can be used to improve yield, the historical change of plant density tolerance of sweet corn is unknown, "said Daljeet Dhaliwal, a doctoral student in the Department of Crop Science of Illinois and the main author of the frontier article of plant science.
Dhaliwal and Marty Williams, an ARS ecologist and part-time professor of the Department of Agriculture, tested the crowding tolerance of sweet corn hybrids from 1934 to 2014. They found that in 80 years, the marketable spike quality per acre increased by 2.85 tons in total when planted at high density, or 0.36 tons per acre every decade.
In order to quantify these historical changes, Williams established contacts in the sweet corn seed industry. Many early hybrid vehicles are no longer available, so the company proposes to rebuild hybrid vehicles from scratch.
"The seed industry is willing to make a lot of efforts to create these hybrids for free. It took us about five years to put the germplasm together," Williams said. "Without broad industry support, this project cannot be realized. I think it reflects the value provided by our research plan."
Williams and Dhaliwal planted one or more hybrids representing every ten years at low density (4000 plants per acre) and high density (32000 plants per acre) within three years. Then they measured the characteristics that are important to growers and processors, including key harvest indicators, such as marketable ear quality, crate output, recovery rate, etc.
In addition to improving the quality of marketable panicles per area of hybrids planted under high density, the crate yield of modern hybrids has also increased. Fresh grain quality and recovery - a measure of how much of ear quality consists of marketable grains - have not changed much over time.
