Glyphosate, applications

Cole, E.C., W.C. McComb, M. Newton, J.P. Leeming, and C.L. Chambers (1998). Response of small mammals to clearcutting, burning, and glyphosate application in the Oregon Coast Range. J. Wildl. Manage., 62(4) 1207-1216. 

Figure 6.15 Deuterated glyphosate application with formulation onto maize leaves, (a) Spontaneous Raman spectrum of deuterated and nondeuterated glyphosate showing the bands generated in the silent region by deuteration (inset shows the hydrogen atoms within the molecule which have been replaced with deuterium), (b) Stimulated Raman spectra of the C—D bands in the deuterated glyphosate. (c) Deuterated gylphosate crystals on a maize leaf...

This classical C-P bond-forming reaction (51) has seen limited application in the glyphosate arena, presumably for lack of suitable substrates that can tolerate the vigorous reaction conditions. Typically, C-P bond formation occurs when an alkyl halide reacts with excess neat trialkyl phosphite at temperatures exceeding 100 °C, near the boiling point of the phosphite. An Arbuzov-based strategy for glyphosate requires the synthesis of the... 

Just as atrazine is important in com, simazine is a pre-emergence triazine that provides broad-spectrum residual weed control in many of the important fruit and nut crops when applied either alone or in combination with a contact product such as glyphosate to control weeds at the time of application (Figure 1.5). 

Atrazine use in ecofallow usually is supplemented with other herbicides. For example, the first herbicide application to wheat stubble often uses glyphosate and 2,4-D or dicamba, with the atrazine application postponed until later in summer to coincide with the emergence of volunteer wheat, cheat, and downy brome. Atrazine can be applied with glyphosate, but antagonism with some atrazine formulations is associated with this tank mixture (Stahlman and Phillips, 1979 Wicks and Hanson, 1995) because of physical binding of inert components in the atrazine formulation with glyphosate (Ahmadi et al., 1980). Farmers know that if rainfall does not move atrazine off the wheat residue and into the soil, control of weeds, and volunteer wheat will be unsatisfactory. 

Atrazine plays a central role in ecofallow because of its low cost, effective weed control, and extended soil activity. Atrazine controls volunteer wheat and most of the winter annual weed complex - including cheat, downy brome, wild mustards, and henbit, plus many spring annuals. No alternative herbicide has similar characteristics. Repeated applications of nonresidual, foliar-applied herbicides such as glyphosate or paraquat are not as economical. 

Lockhart, W.L., Billeck, B.N. and Baron, C.L. (1989) Bioassays with a floating aquatic plant (Lemna minor) for effects of sprayed and dissolved glyphosate, in M. Munawar, G. Dixon, C.L Mayfield, T. Reynoldson and M.H. Sadar (eds.), Environmental Bioassay Techniques and their Application Proceedings of the 1st International Conference held in Lancaster, England, 11-14 July 1988, Kluwer Academic Publishers, Dordrecht, Netherlands, pp. 353-359. 

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