Pest Management Science (2013) 69, 228-232

Martin M. Vila-Aiub, Pedro E. Gundel, Qin Yu and Stephen B. Powles (2013)
Glyphosate resistance in Sorghum halepense and Lolium rigidum is reduced at suboptimal growing temperatures
Pest Management Science 69 (2), 228-232
Abstract: Background
Glyphosate resistance in populations of the C₄ perennial Sorghum halepense (Johnsongrass) and C₃ annual Lolium rigidum (rigid ryegrass) has evolved and been documented in many cropping areas around the globe. In S. halepense and in the majority of reported cases in L. rigidum the glyphosate resistance trait has been associated with a mechanism that reduces glyphosate translocation within plants. Here, the significant decrease in the glyphosate resistance level when resistant plants of S. halepense and L. rigidum are grown at suboptimal cool temperature conditions is reported.
Results
Lowering temperature from 30 to 19 °C in S. halepense and from 19 to 8 °C in L. rigidum significantly reduced both plant survival and above-ground biomass produced by glyphosate-resistant plants. Thus, glyphosate resistance parameters significantly decreased when glyphosate-treated resistant plants of both species were grown under non-optimal temperature conditions. The results suggest that the resistance mechanism against glyphosate damage is less efficient at optimal growing temperatures.
Conclusion
It is possible to increase the control of glyphosate-resistant S. halepense and L. rigidum populations by treatment with glyphosate during growing conditions at suboptimal low temperatures. Conversely, glyphosate failure will continue to occur on glyphosate-resistant populations treated during periods of higher temperatures.
(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): Martin M. Vila-Aiub, Qin Yu, Stephen B. Powles

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sorghum halepense (weed)
	Lolium rigidum (weed)