Roy Bailey writes
In article , Ophelia
writes
[snipped]

Crops (75% worldwide) have been modified so that these herbicides can be
sprayed directly onto the plants without killing them. This, of course, so
that the weeds will die, but the plant will not.
How does the glyphosate know which are weeds and which are plants?

It doesn't have to know. What the article is claiming is that crops have
been modified so they are no longer susceptible to it. Therefore the
glyphosate kills off all plants (whether crops or weeds) that haven't
been modified to be resistant, and fails to kill those which have been
modified.
--
Kay