Giant Ragweed Plants (image) Purdue University Caption Purdue scientists found that soil microbes may play a role in how those weeds react to the popular herbicide glyphosate. Here, glyphosate-susceptible biotypes of giant ragweed react differently to the herbicide. The plant on the left is in sterilized field soil void of microbes, while the plant on the right is in unsterilized soil. Credit Photo provided by Jessica Schafer Usage Restrictions None 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.