Grass spectrum

A broad-spectrum grass and broadleaf corn herbicide Regulated metabolites in groundwater include the parent, isoxaflutole (RPA 201772), and its metabolites RPA 202248 [2-cyclopropylcarbonyl-3-(2-methylsulfonyl-4-trifluoromethylphenyl)-3-oxopropanenitrile] and RPA 203328 (2-methanesulfonyl-4-trifluoromethylbenzoic acid)... 

Sulfentrazone is a broad-spectrum, pre-emergent herbicide that provides good control over broadleaf weeds, grasses and sedges in crops and turf. The metabolism of sulfentrazone in animals and plants is similar. The major plant metabolite of sulfentrazone is 3-hydroxymethyl sulfentrazone (HMS). The soybean tolerance of 0.05 mg kg includes residues of sulfentrazone plus its major metabolite, HMS. The rotational crop tolerance includes residues of sulfentrazone and its major metabolites, HMS and... 

In contrast to the broad-spectrum herbicides, others are more selective. The phenoxy herbicides, which include chemicals such as 2,4-D, 2,4,5-T, and MCPA, are toxic to broad-leaf plants but do not affect narrow-leaf plants such as grasses. 

The term "herbaceous" applies, botanically, to any plant that does not form a persistent woody stem. Confusingly, though, "herbaceous" is commonly used as shorthand for "herbaceous perennial," to mean plants such as hostas, delphiniums, and the like, that die down in the winter, and return every spring. These plants may also be referred to simply as "perennials." This chapter, however, covers the whole spectrum of herbaceous plants—annuals, biennials, bulbs, and half-hardy perennials grown as annuals, as well as herbaceous perennials, and including grasses. 

Imidazoles. Imidazole herbicides arc generally used for selective pre-nnd post-cmcrgencc control of grass and broadleaved weeds In croplands. Bulhida7olc and ima/upyr arc used for broad-spectrum, nonselcctive weed control in noncroplands. 

On the other hand, the broad weed control spectrum of chloramben, which was introduced in 1959, brought with it widespread acceptance. As an over-the-row band for control of both broadleaf and grass weeds, cost was minimized. With good crop tolerance, chloramben dominated the early soybean herbicide market. During 1972, 85% of the product was applied as the granular formulation (Table 4.2). However, as application practices changed for the soybean crop, banded applications became an inconvenience. Herbicides such as metribuzin (a triazine herbicide), linuron, and bentazon, which could be applied as an affordable broadcast treatment, soon became products of choice, and the marketing of chloramben was eventually discontinued in 1990. 

Triazines are selective herbicides used to control a wide spectrum of grass and broadleaf weeds in cereal, oilseed, and horticultural crops. Triazine herbicides kill weeds by interfering with the electron transport chain in photosystem II (PS II). These herbicides bind to the QB protein in the PS II reaction center and block the flow of electrons through the photosynthetic electron transport chain. 

Broad-spectrum weed control Atrazine and simazine control a broad spectrum of broadleaf and grass weeds. In fact, of the 28 weeds species considered in the analysis, atrazine provides a higher level of control of a greater number of them than any other herbicide. 

Uses nonselective, post-emergent, broad spectrum herbicide to control annual and perennial grasses, sedges, broadleaf, and emerged aquatic weeds also used to control insects on fruit trees. 

Structure-activity studies have shown the crucial role of the trifluoromethyl group in optimum biological activity of bleaching herbicides [38], Isoxaflutole (Balance , Merlin ) is a root or foliar uptake systemic herbicide with broad-spectrum control in corn and sugarcane of both grass and broadleaf weeds [39], Isoxaflutole is rapidly converted in plants and in soil to the diketonitrile form, which is the biologically active species (Fig. 7) [40],... 

Flufenacet (Cadou , Drago ), the 5-trifluoromethyl-1,3,4-thiadiazol-2-yloxy acetanilide herbicide developed by Bayer CropScience, belongs to the oxyacet-amide class of herbicides. Flufenacet is effective in controlling a broad spectrum of annual grass, hedges, and small broadleaf weeds [74]. 

Uses Glyphosate is a phosphanoglycine and does not inhibit cholinesterase activity.12,13 Glyphosate is a broad-spectrum, nonselective systemic herbicide with moderate toxicity. Essentially, it is useful on all annual and perennial plants including grasses, sedges, broadleaf weeds, and woody plants. It is used on noncropland and on a variety of crops.17,28-34... 

Selective herbicide with broad spectrum grass control and control of some broad leaved weeds in maize, soybeans, sunflower, wheat, rice... 

Broad spectrum Animals. Rapidly excreted by rat, goat, and herbicide controlling hen. Metabolism via cleavage of the molecule grasses followed by conjugation of flurophenyl... 

For heavy species, the many ionization states coupled with their many open shells in intermediate coupling can lead to a grass-like spectrum. For this quasi-continuum it is not practicable or informative to separate or distinguish individual lines. In ADAS, the composite emission as a function of wavelength, in a spectral interval is described by an envelope feature emis-sivity coefficient or FPEC for short. As for a PEC, it is associated with a... 

Unsubstituted uracils have no herbicidal activity but certain derivatives substituted in the 3,5,6-positions are active. The most important examples are bromouracil, terbacil, and lenacil. These compounds were introduced by DuPont in 1963. These herbicides are applied to the soil and are used for selective weed control. Bromacil and terbacil are pre- and postemergence herbicides they control a wide spectrum of grass and broadleaf weeds when applied early in the growing season. These compounds must be carried to the roots by soil moisture, where they are absorbed and translocated to the rest of the plant. This family of herbicides is used for asparagus, sugar cane, pineapple, apple, and citrus crops. 

Halogenated aiyloxyphenoxypropionic acids are a new class of herbicides used for the selective removal of grass species. In commercial preparations, they are present as alkyl esters. In negative-ion ESI, haloxifop, fluazifop, and diclofop all show similar behaviour. The deprotonated molecule is the base peak in the spectrum. Weak formate and acetate adducts occur, and a fragment due to the loss of the propionate part [45]. The analysis of fluazifop and its butyl ester, fenoxaprop, quizalofop and haloxyfop and their ethyl esters, and diclofop and its methyl ester was reported. The free acids were analysed in negative-ion mode, and the esters in positive-ion mode. The esters showed sodium and potassium adducts next to the protonated molecules. The adduct formation was suppressed by the addition of 25 mmol/1 formic acid to the mobile phase. The influence of the orifice potential on the appearance of their mass spectra was studied [46-47]... 

Paraquat is used as a broad-spectrum herbicide on weeds and grasses in agricultural and nonagricultural areas. It is used as a desiccant on tomatoes, cotton, beans, soybeans, potatoes, sunflowers, and sugar cane to aid in harvesting and to induce resin soaking on pine trees. 

Caraway is a crop with very small competitive ability against the majority of weed species and has slow development at the beginning. The timing of herbicides application is very important, especially at biennial caraway. There is a recommendation for regulating the perennial species (couch grass) and hardly regulated weeds (common thistle, sorrel) in a fore crop. The spectrum of the herbicides registered into caraway is narrow. The different sensitivity of cover crop and caraway to the herbicides plays the important role, as well as the coordination of the application term from the point of view of the efficiency and the sensitivity (Vaculik, 2006 2007 2008 Vaculik et al., 2008). 

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