Setting up Blue Dye Sprayer (IMAGE) American Society of Agronomy Caption Matthew Walker (left) and Genevieve Ali (right) mixing blue dye with water from a nearby on-farm reservoir before the experiment. Credit Merrin Macrae 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.