Optimization herbicide

In summary, the structural elements of optimal herbicidal activity in pro-pyzamide are the 3,5-dichloro-phenyl group, the dimethlypropynyl group and the carbainoyl function. 

These problems of sufficient available herbicide can be partly solved by using supra-optimal herbicide concentrations. Usually 0.1 to ImM solutions are used. These high Concentrations can lead to false positives. 

Numerous substituted p pmidine and tiiazine amines have found utility as precursors to highly active and crop selective sulfonylurea herbicides. In the process of optimizing herbicidal efficacy and crop safety within this class, a variety of structurally diverse heterocyclic amines have been synthesized and evaluated. This paper reviews the methods of preparation that have been developed for some of the different structural types used as intermediates to active sulfonylurea herbicides. These methods include cyclizations, rearrangements, and side-chain metalations that have led to furo[2,3-d]pyriiindines, pyrazinones, and selectively functionalized pyrimitoes, triazines, triazoles, and pyridines. 

Nonchemical or traditional practices, such as weed seed removal, optimal crop seeding rates, crop selection, enhanced crop competitiveness, crop rotation, and mechanical weed control are all important components of an effective weed management program (458,459). In the context of modern intensive chemical herbicide appHcation, nonchemical practices may even represent an innovative approach to weed management and should receive careful consideration. 

LC/MS/MS is the preferred means of detection, quantitation, and confirmation of sulfonylurea herbicides in biological and environmental matrices. Therefore, recommendations for establishing and optimizing LC/MS/MS analyses common to all matrices are given first, followed by specific rationales for methods and sample preparation techniques for plant, soil, and water matrices. 

Plant uptake, of herbicides, 13 310 Plant viruses, 3 135 Plant waxes. See Vegetal waxes Plant-wide optimization, 20 675 PlantWise software, 19 520-521 Plaque, 3 710-711... 

It will be noted that in isolated spinach chloroplasts, one hardly needs to worry about making an inhibitor too hydrophobic i.e. optimal log P = 5.2 for the N,N-dimethyl- and 5.4 for the methoxymethyl-ureas. In contrast to the isolated chloroplast studies, one sees from a list of commercially successful herbicides for which log P values have been measured or calculated, (Table IV) that getting the herbicide to the chloroplast in the living plant places much greater restrictions on its hydrophobic-hydrophilic balance. Indeed, the average log P of this set is only 2.54. 

Natural triketones and other natural products also inhibit The natural products tend to be competitive inhibitors of HPPD, whereas the synthetic herbicides have been optimized and bind irreversibly to the enzyme. 

Auxins produce many changes in cells, including increased wall plasticity, enhanced respiratory rate and alterations in nucleic acid metabolism. Although the primary mode of action of auxins is not fully understood the development of the chemistry has progressed rapidly. Early discoveries identified and exploited the herbicide potential of super-optimal concentrations of auxin (Chapter 2, Herbicides) but their... 

McLaughlin, R.A. and B.S. Johnson (1997). Optimizing recoveries of two chlorotriazine herbicide metabolites and 11 pesticides from aqueous samples using sohd-phase extraction and gas chromatography-mass spectrometry. J. Chromatogr. A, 790 161-167. 

Prosen, H., L. Zupancic-Kralj, and J. Marsel (1995). Optimization of an analytical procedure for the determination of triazine herbicides in environmental samples. J. Chromatogr. A, 704 121-130. 

Brandao et al. also applied the bottom-up approach to compare seed-protein profiles of herbicide-tolerant soybean and its near-isogenic line (60). Some 2-DGE parameters such as the loaded mass of the proteins, the pH separation range, and manual/automatic image editing were optimized prior to the evaluation (Figure 2). Of the 10 proteins with at least 90% variation found to be differentially expressed between the GM soybean and its counterpart, 8 proteins were successfully identified by MALDI coupled to a quadrupole (Q)-TOF MS. 

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