scenario SENWES

52
••• DEVELOPING AGRICULTURE
Weed out
glyphosate resistant weeds
PRODUCERS WHO PLANT GLYPHOSATE
OR ROUNDUP READY RESISTANT
CROPS SEASON AFTER SEASON,
RUN THE RISK OF CULTIVATING
GLYPHOSATE RESISTANT WEEDS.
SINCE MOST MAIZE, SOYBEAN
AND COTTON CULTIVARS HAVE A
GLYPHOSATE RESISTANT TRAIT, THE
MANAGEMENT OF THESE WEEDS
OFFER AN EASY AND EFFECTIVE
SOLUTION.
> TEXT: JULIAS RAMOHLABI
When continuously planting
glyphosate resistant crops, the risk of developing
glyphosate resistant weeds can be significantly
redu ced by using a variety of herbicides that control
each weed species on your crops and by adhering to
certain guidelines. In doing so, you will be able
to apply a specific course of action that suits the
situation.
Glyphosate (N-[phosphonomethyl] glycine) is
a broad-spectrum systemic herbicide used to kill
weeds, especially perennials. It is typically sprayed
and absorbed through the leaves of the plant.
By engineering and inserting a glyphosate resistant
gene in the seed of cultivars such as soybean,
>
maize and cotton, these cultivars greatly improve
conventional farmers’ ability to control weeds, since
glyphosate can be sprayed on fields without damaging
the crop.
Phosphonic acids are non-selective, broad-spectrum,
post-emergence, systemic herbicides that are
active on leaves and other green parts of plants. It
works by disturbing various physiological and biological
processes in the plant. The most important effect
is the inhibition of aromatic amino acid synthesis,
which causes a chain reaction of inhibiting other
synthesis processes in the plant. The most common
symptoms of the phosphonic acids are termination
of growth and chlorosis of the foliage, followed by
necrosis.
AN INNOVATIVE SOLUTION
Glyphosate has revolutionised broad-spectrum weed
control in maize, soybeans and other crops, through
the insertion of a glyphosate resistant gene in the
seed.
Growers have widely embraced the technology,
because it provides convenient, effective and econo
mical weed control in maize and soybeans.
THE DOWN SIDE
Research has shown that intensive and long term
exclusive use of glyphosate can lead to the development
of glyphosate resistant weeds.
MANAGING THE PROBLEM
Integrated management practices can minimize this
senwes.co.za • April 2010