Agriculture Reference
In-Depth Information
There is a wide range of weed management
tactics available to wheat growers in Australia.
Some of these are used in the rotation prior to the
wheat phase, e.g., spray-topping pastures or crop-
topping pulse crops, while others such as time of
seeding, seed rate (or crop density), cultivar selec-
tion, and herbicide choice are implemented during
the wheat growing season. Integration of these
tactics has provided effective management of
weed populations in wheat.
REFERENCES
Anderson, R.L. 1993. Jointed goatgrass (
Aegilops cylindrica
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ecology and interference in winter wheat. Weed Sci.
41:388-393.
Anderson, R.L. 1997. Cultural systems can reduce reproduc-
tive potential of winter annual grasses. Weed Technol.
11:608-613.
Anderson, R.L. 2003. An ecological approach to strengthen
weed management in the semi-arid Great Plains. Adv.
Agron. 80:33-62.
Anderson, W.K., and D. Sawkins. 1997. Production practices
for improved grain yield and quality of soft wheats in
Western Australia. Aust. J. Exp. Agric. 37:173-180.
Andreasen, C., J.C. Streibig, and H. Haas. 1991. Soil proper-
ties affecting the distribution of 37 weed species in Danish
fi elds. Weed Res. 31:181-187.
Baumhardt, R.L., and R.L. Anderson. 2006. Crop choices
and rotation principles. p. 113-139.
In
G.A. Peterson, P.
W. Unger, and W.A. Payne (ed.) Dryland agriculture.
ASA, CSSA, and SSSA, Madison, WI.
Bell, A.R., and J.D. Nalewaja. 1968. Competition of wild oats
in wheat and barley. Weed Sci. 16:505-508.
Blackshaw, R.E. 1994a. Differential competitive ability of
winter wheat cultivars against downy brome. Agron. J.
86:649-654.
Blackshaw, R.E. 1994b. Rotation affects downy brome
(
Bromus tectorum
) in winter wheat (
Triticum aestivum
).
Weed Technol. 8:728-732.
Blackshaw, R.E. 2005. Tillage intensity affects weed com-
munities in agroecosystems. p. 209-221.
In
S. Injerjit (ed.)
Invasive plants: Ecological and agricultural aspects.
Birkhäuser Verlag, Basel, Switzerland.
Blackshaw, R.E. 2006. Evolving on-farm management
systems: The Canadian experience. p. 17-21.
In
C. Preston,
J.H. Watts, and N.D. Crossman (ed.) Proc. Australian
Weeds Conf., 15
th
, Adelaide, South Australia. 24-28 Sept.
2006. Weed Management Society of South Australia,
Adelaide, Australia.
Blackshaw, R.E., H.J. Beckie, L.J. Molnar, T. Entz, and J.R.
Moyer. 2005a. Combining agronomic practices and herbi-
cides improves weed management in wheat-canola rota-
tions within zero-tillage production systems. Weed Sci.
53:528-535.
Blackshaw, R.E., F.J. Larney, C.W. Lindwall, P.R. Watson,
and D.A. Derksen. 2001a. Tillage intensity and crop rota-
tion affect weed community dynamics in a winter wheat
cropping system. Can. J. Plant Sci. 81:805-813.
Blackshaw, R.E., L.J. Molnar, and H.H. Janzen. 2004. Nitro-
gen fertilizer timing and application method affect weed
growth and competition with spring wheat. Weed Sci.
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Blackshaw, R.E., J.R. Moyer, R.C. Doram, and A.L. Boswell.
2001b. Yellow sweetclover, green manure, and its residues
effectively suppress weeds during fallow. Weed Sci.
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Blackshaw, R.E., J.R. Moyer, K.N. Harker, and G.W.
Clayton. 2005b. Integration of agronomic practices and
herbicides for sustainable weed management in zero-till
barley fi eld pea rotation. Weed Technol. 19:190-196.
FUTURE PERSPECTIVES
Preventative weed management is highly effective
but routinely overlooked because it is complex
and involves the integration of many practices.
Greater understanding of the complex interac-
tions involved in the introduction, establishment,
and dispersal of weed species at the national,
regional, and farm levels is necessary for greater
adoption of these effective weed control
strategies.
Weed populations adapt to changes in farm
management. Farmers must strive to keep weeds
off balance by frequently altering management
practices and maximizing the competitive advan-
tage of the crop at the expense of weeds. A good
stand of healthy wheat can be very competitive
with weeds and more effort needs to be put into
developing integrated systems that maximize this
advantage.
Overreliance on herbicides for weed control
has led to weed resistance and weed shifts that
complicate weed management. With a limited
array of available herbicide classes, weed resis-
tance will remain a challenge to wheat production
in the future.
The ubiquitous use of glyphosate jeopardizes
the sustainability of no-till systems that have
proven so effective for diversifying and intensify-
ing wheat production systems in semiarid envi-
ronments. Proper glyphosate stewardship is
critical to maintaining these effective production
systems. Sustainable weed management in wheat
will best be achieved through continued develop-
ment and adoption of integrated weed manage-
ment and crop production practices.
