Evaluate Perennial Groundcover (IMAGE) American Society of Agronomy Caption Researcher Jeremy Singer evaluates perennial groundcover grass growing between rows of corn. Credit Iowa State University photo credit Dan Kuester. Usage Restrictions Please use with story only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.