Im not sure what this could be. Had a large bare patch reseeded in May and the grass came in great. Looked awesome and i thought we were in good shape. About 10 days ago I started to notice patches that seemed unhealthy. On closer inspection it looks like there is this white fuzz wrapped around the grass that seems to be killing it. Touching it i get this chalky substance on my hand. It’s continued moving through the new patch of grass but, not affecting my older established grass. We have had a lot of rain and its been very humid here in the Northeast.