Context:
to overreliance on herbicides and, in particular, on glyphosate. In
the United States, glyphosate use has increased by a factor of more
than 250 - from 0.4 million kg in 1974 to 113 million kg in
2014. Global use has increased
by a factor of more than 10. Not
surprisingly, glyphosate-resistant weeds have emerged and are
found today on nearly 100 million acres in 36 states. Fields must
be now be treated with multiple herbicides, including 2,4-D, a com-
ponent of the Agent Orange defoliant used in the Vietnam War.
MOre:
http://www.nejm.org/doi/pdf/10.1056/NEJMp1505660