Impacts on Weeds - Climate Resilient Agriculture for Ensuring Food Security - page 198

controls would help minimize crop losses
(Pimentel et al. 1993 ). Nonchemical controls
include crop rotations, biological controls, alter-
ing planting dates and fertilizer and irrigation
applications, and soil management and tillage.
These technologies could help minimize pro-
jected weed losses and thereby help maintain
crop yields.

modifi ed to withstand the herbicide glyphosate
(the active ingredient in Monsanto's herbicide
Roundup). It is also known as “glyphosate-
tolerant corn.”
LibertyLink corn is genetically engineered for
tolerance to over-the-top applications of the non-
selective herbicide Liberty (glufosinate

ammonium).
Dicamba- , glufosinate-, and glyphosate-
tolerant corn is designed to build on the Roundup
Ready Xtend Crop System and provide farmers
with additional herbicide-tolerance options. This
product would contain multiple herbicide-
tolerance traits enabling use of herbicides with
different modes of action, expanding growers'
options to protect their crop from weed
infestations.
Using modern biotechnology, Monsanto
Company has developed Roundup Ready cotton
plants that confer tolerance to glyphosate, the
active ingredient in Roundup agricultural
herbicides.
LibertyLink cotton has been genetically modi-
fi ed to be tolerant to Liberty herbicide, allowing
for effective postemergence herbicide manage-
ment system in cotton.
Roundup Ready canola has been modifi ed
using gene technology to tolerate glyphosate, the
active ingredient in Roundup agricultural
herbicides.
The LibertyLink trait (glufosinate resistance)
is available in top-performing InVigor canola
hybrids.
Roundup Ready sugar beets have been
enhanced through biotechnology and contain
the Roundup Ready gene to tolerate applica-
tions of labeled Roundup agricultural herbi-
cides, which contain the active ingredient
glyphosate.
Ribas et al. ( 2006 ) introduced the bar gene in
Coffea canephora and C. arabica . The bar gene
inactivates the herbicide ammonium glufosinate,
which is normally used as a nonselective pre-
emergence herbicide and also for preharvest
desiccation.
Commercially available genetically modifi ed
herbicide-tolerant crops are presented in
Table 10.3 (Castle et al. 2006 ).

10.11.8 Transgenic

Herbicide-Tolerant Crops

Another important issue regarding pest manage-
ment in the future centers on the role of biotech-
nology in crop protection. The next 20 years will
likely see a substantial increase in the use of
genetically engineered plants. Some of these
plants have been engineered so that the applica-
tion of herbicides destroys weeds but not the eco-
nomic crop. Other genetically engineered plants
have been designed to resist pests such as stem
borers and nematodes without the need for pesti-
cides. Others are expected to combine both herbi-
cide resistance and insect resistance in one seed.
The Roundup Ready (RR) technology incor-
porates genetic resistance to glyphosate into crop
plants by inserting a single bacterial gene that
modifi es 5-enolpyruvylshikimate-3-phosphate
(EPSP) synthase, an enzyme essential for plant
growth.
GTS 40-3-2 (also known as Roundup Ready
Soybean) is a genetically engineered variety of
glyphosate-resistant soybeans produced by
Monsanto. The major problem in soy farming is
weeds; thus, GTS 40-3-2 is revolutionary. The
most widely utilized herbicide-tolerant crop in
production today is the Roundup Ready soybean
resistant to the broad spectrum herbicide Roundup
that contains the active ingredient glyphosate.
LibertyLink soybeans were introduced in
2009. These soybeans allow the use of Ignite her-
bicide as a postemergence treatment. Ignite is a
newer, more concentrated formulation of Liberty
herbicide. This gives soybean producers an
option to Roundy Ready soybeans.
Roundup Ready Corn (RR Corn) is a geneti-
cally engineered corn that has had its DNA