A new study conducted by the University of Illinois at Urbana-Champaign found that the yield of sweet corn, when grown at high density, has increased steadily over the past 80 years. This historical analysis underscores the importance of growing modern density tolerant maize species in their optimal density and suggests ways to further improve their density tolerance.
“Over time, the constant improvement in plant density tolerance has made a major contribution to increasing the genetic yield of field maize. While our recent research suggests that plant density tolerance in modern sugar corn hybrids could be used to improve yield, historical changes in plant density tolerance in sweet corn were unknown, ”said study leader Daljeet Dhaliwal, PhD student in the Department of Crop Sciences at the University of Illinois.
Together with Marty Williams, an adjunct professor of ecology, Dhaliwal tested the displacement tolerance of sweet corn in hybrids from 1934 to 2014. They found that the marketable ear mass increased by a total of 2.85 tons per acre at high crop densities during this period and an average of 0.36 tons per decade.
The researchers grew one or more hybrids over the course of three years, representing each decade with both low (4,000 plants per acre) and high density (32,000 plants per acre). Next, they measured key harvest metrics like marketable ear mass, box yield, and recovery. They found that marketable ear mass and box yield improved in hybrids grown under high density. Thus, modern hybrids appear particularly suitable for growth in high density.
“The system architecture has become more compact. Plants put fewer resources into the vegetative tissue, so there is less fresh biomass and less tillering. This means that modern plants are really suitable for growing at higher densities. There is less interference, right? But if you plant them in low density, where there is no competition, these plants will no longer produce older hybrids, ”explains Dhaliwal.
On the other hand, the scientists found that the fresh kernel mass and recovery did not change significantly over time.
“No improvement over 80 years indicates a potential breeding goal. What if we could improve recovery? ”Said Williams. “Until the last decade, few sweet corn breeding programs have measured recovery. Instead, breeders focused on other important traits, particularly eating quality and disease resistance. But now that we know how little recovery has improved, it may be worth aiming for. “
The study is published in the journal Frontiers in Plant Science.
By Andrei Ionescu, Earth.com Staff Writer