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AteToday?
Thank a Farmer.
Better Farming
December 2016
CROPS:
THE
LYNCH
FILE
Stop spreading weeds
You need to be proactive to reduce the spread of resistant weeds. Here are some tips.
by PATRICK LYNCH
A
recent email got me thinking.
It started, “Pat, can you offer
us some help on how we can
control/kill this weed? This is mostly
a problem with our livestock custom-
ers. Some are growing corn in their
rotation and some are not. The
roadside ditches and waste areas are
full of this so we know how this weed
is spreading into most fields. It is
really taking over many fields, both in
direct-seeded forages as well as cereal
under-seeded with alfalfa-grass
mixtures.” The email sender was
referring to wild carrot, sometimes
called Queen Anne’s lace – and
sometimes called other things.
This email made me think of two
things.
1) Weeds spreading to a farm from
off the farm.
2) Dealing with resistant weeds.
Wild carrot was the first-known
resistant weed in Ontario. In the late
1950s, wild carrot developed resis-
tance to 2,4-D because the townships
sprayed yearly with this herbicide.
Weed resistance is a lot worse than
most growers believe. If more Ontar-
io growers knew how bad this issue is,
I believe they would take weed
control more seriously.
Here are some facts. There are
farms in the United States where the
land cannot be rented because of
weed resistance. These weeds did not
just “appear;” they were spread. Some
growers are now hand pulling weeds,
which can be costly. There are also
counties in the United States where
weed control is strictly enforced. You
are not allowed to let certain weeds
go to seed.
In Ontario, maybe we need to do
this on a township basis. Have
growers voluntarily agree to control
weeds, and encourage their neigh-
bours to do so as well. In Europe,
farmers may lose the use of glypho-
sate for the 2018 growing season. But
many producers there are not upset
since glyphosate has lost its purpose
on many farms. Rather, they are
promoting crop rotations, fallow and
tillage to control weeds.
If you seriously want to delay the
development and spread of weeds to
your farms there are a number of
simple steps you can take.
Stop the spread of weeds from
roadsides and fence rows. Ask your
township what the local regulations
are – but we have to try to control the
spread of weeds from public land.
Some growers level the roadsides and
clip them. This helps to give access to
fields at many points and keeps weeds
under control.
Some of you are planning on using
the new Roundup Ready 2 Xtend
soybeans to control weeds, but you
cannot rely solely on the new Round-
up XtendiMax herbicide to solve your
weed resistance problems. You must
use multiple modes of action of
herbicides when you spray glypho-
sate-resistant weeds. Otherwise you
will quickly develop weeds that are
resistant to multiple herbicides.
The next step is to get serious
about selecting your herbicides – and
record them. You should keep a
record of what was sprayed each year
and try to use a different herbicide
group in the following year. If you
never plant the same crop twice in a
row it is easier to rotate herbicides.
One of the reps I work with in the
crop protection industry says, “Using
a different mode of action from year
to year is not enough. That’s an old
recommendation and it won’t work
any longer. I am a firm believer that
using multimodes of action acting on
the same species needs to become an
annual practice.
“And going forward immediately,
multi will need to mean more than
This year was another classic one in which weeds got too big to be easily controlled.
Some growers level the
roadsides and clip the weeds.