Gardening
can be very relaxing, especially when we are looking after our plants indoors.
When nobody is watching, many of us talk to them. Of course, whether or not
this cheers them up or it’s just for our benefit is still a subject for debate
over a glass or two.
As
usual, the focus is on our communication skills and we totally ignore those of
the plants. Not so with Gagliano et al who
have been taking an interest in the communication skills of red hot chili
peppers – not the rock band you understand, but the plants and you can read
about their adventures in the Public Library of Science (1).
They
had noted that plants are known to communicate chemically, both through the
soil and through the air, in addition to using light at the far-red end of the
spectrum. So they set out to see if that was the limit of their repertoire. They
chose chili plants and watched the progress of baby plants, firstly on their
own, but then in the presence of adult chili baby sitters or, more
threateningly, adult fennel plants. I must admit that I was blithely ignorant
about the long-standing issues between chili and fennel.
The
experiments were set up so that seed germination and early growth could not be
affected by chemical messages nor by light signals. The results showed that not
only did more of the chili seeds germinate when fennel plants were present, but
the plants grew longer roots and stems.
The
question remains open as to how the seeds and seedlings knew that fennel plants
were lurking around out of site, but they responded positively in two years
worth of experiments. The authors speculate on weak magnetic fields and sound,
but maybe the lab techs gave it away by talking to them. Whichever is the
cause, chili-fennel communication is effective.
- http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037382
