Plants can use underground communication to find out when neighbors are stressed.
Corn seedlings that grow close together give off underground signals that impact the growth of nearby plants, reports a study published May 2, 2018 in the open-access journal PLOS ONE by Velemir Ninkovic from the Swedish University of Agricultural Sciences, Sweden, and colleagues.
Read more at: https://phys.org/news/2018-05-underground-neighbors-stressed.html#jCp
More information: Elhakeem A, Markovic D, Broberg A, Anten NPR, Ninkovic V (2018) Aboveground mechanical stimuli affect belowground plant-plant communication. PLoS ONE 13(5): e0195646. doi.org/10.1371/journal.pone.0195646