I heard this on the radio a few days ago, and it seems like nonsense to me. Grass can’t run away or defend itself, so sending out a signal doesn’t seem much use. And even if it could, how does grass sense nearby grass being murdered?
On the other hand (leaf?), this is not new news, and this makes perfect sense, as the scent release attracts a predator that will do something about the plant’s attackers…
