Kudos to the NC state team for setting up this control, and digging into the results, especially when the purpose of their experiments was different (their intent was to find a better way to deliver pesticides).
It is amazing how many times this happens - unintended or unanticipated results from an experiment, often peripheral results, which turn out to be extraordinarily interesting (usually for a different purpose as the original experiment), if observed and followed-up on with rigor and innovation.