Many agricultural producers apply glyphosate to glyphosate-resistant crops to control weeds, including Palmer amaranth. Populations of this weed in Tennessee not completely controlled by glyphosate were examined. Field and greenhouse research confirmed that two separate populations had reduced biomass sensitivity (1.5× to 5.0×) to glyphosate compared to susceptible populations, although the level of resistance was higher based on plant mortality response (about 10×). Shikimate accumulated in both resistant and susceptible plants, indicating that 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) was inhibited in both biotypes. These results suggest that an altered target site is not responsible for glyphosate resistance in these Palmer amaranth biotypes.

Preplant applications of two 2,4-D formulations and dicamba were evaluated for injury to no-till soybean. Herbicides applied 28 or 21 d before planting (DBP) at 0.56 kg ae/ha for the 2,4-D formulations and 0.28 kg ae/ha for dicamba did not injure soybean. At 14 DBP soybean injury was lower (< 6%) with applications of 2,4-D than with dicamba (13% to 17%). Injury increased when herbicides were applied at 7 DBP with soybean injury from both 2,4-D (< 11%) and dicamba (< 38%). When the herbicides were applied at planting soybean injury was < 18% with the 2,4-D formulations and < 73% with dicamba. Soybean yields were unaffected by the injury from herbicides applied 21, 14, and 7 DBP. However, soybean yield was decreased to 870 kg/ha in 2005 when dicamba was applied at planting compared to the nontreated check (1,950 kg/ha)

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This annual review of X-ray fluorescence covers developments over the period 2007-2008 in instrumentation and detectors, matrix correction and spectrum analysis procedures, X-ray optics and micro-fluorescence, synchrotron XRF, TXRF, portable XRF and on-line applications as assessed from the published literature. The trend set in previous years continues with an increase in the number of papers published on applications for XRF, including sample preparation, geological, environmental, archaeological, forensic, biological, clinical, thin films, chemical state and speciation studies. Earlier literature has not been ignored in that some of Archimedes oldest writing, previously hidden from sight in a medieval prayer book has now been revealed thanks to the power of modern m-SRXRF. X-ray optics now benefit from the use of poly-capillaries systems, equipment portability has been extended to include the TXRF configuration and readers will find several papers on the use of both two and three dimensional imaging to support environmental, geological and biological studies. The writing team would welcome feedback from readers of this review and invite you to complete the Atomic Spectrometry Updates questionnaire on www.asureviews.org. 9 Applications 9.1 Sample preparation 9.2 Geological and industrial minerals 9.3 Environmental 9.3.1 Aerosols and particulates 9.3.2 Consequences of industrial activity 9.3.3 Other environmental studies 9.4 Archaeological, cultural heritage and forensic 9.5 Industrial 9.6 Clinical and biological 9.7 Thin films and coatings 9.8 Chemical state and speciation 10 Abbrevations 11 References

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