Turfgrass Cross-Section (IMAGE) Penn State Caption The white mycelium that cause thatch collapse are easily seen in this photo of a turf sample from a diseased patch. Credit College of Agricultural Sciences, Penn State Usage Restrictions non commercial use 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.