Weed Biology and Management (2009) 9, 46-53

Robert E. Blackshaw and Randall N. Brandt (2009)
Phosphorus fertilizer effects on the competition between wheat and several weed species
Weed Biology and Management 9 (1), 46-53
Abstract: Information on phosphorus (P) fertilizer affecting crop-weed competitive interactions might aid in developing improved weed management systems. A controlled environment study was conducted to examine the effect of three P doses on the competitive ability of four weed species that were grown with wheat. Two grass and two broad-leaved weed species were chosen to represent the species that varied in their growth responsiveness to P: wild oat (medium), Persian darnel (low), round-leaved mallow (high), and kochia (low). Wheat and each weed species were grown in a replacement series design at P doses of 5, 15, and 45 mg P kg⁻¹ soil. The competitive ability of the low P-responsive species, Persian darnel and kochia, decreased as the P dose increased, supporting our hypothesis that the competitiveness of species responding minimally to P would remain unchanged or decrease at higher P levels. As expected, the competitiveness of the high P-responsive species, round-leaved mallow, progressively improved as the P dose increased. However, wild oat's competitive ability with wheat was not affected by the P fertilizer. The results suggest that fertilizer management strategies that favor crops over weeds might deserve greater attention when weed infestations consist of species known to be highly responsive to higher soil P levels. The information gained in this study could be used to advise farmers of the importance of strategic fertilizer management in terms of both weed management and crop yield.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Robert E. Blackshaw

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Avena fatua (weed)	Wheat (Triticum)
	Bassia scoparia (weed)	Wheat (Triticum)
	Malva pusilla (weed)	Wheat (Triticum)
	Lolium persicum (weed)	Wheat (Triticum)