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/brokenbar 168 /dieresis /copyright /ordfeminine 172 /logicalnot /.notdef /registered /macron Sulfentrazone is a soil-applied preemergence herbicide used in soybean, sugarcane, sunflower, tobacco, and some turf species to control annual broadleaved weeds and some annual grasses. /F11 16 0 R endobj G. Euel Coats, Steven T. Kelly, in The Triazine Herbicides, 2008. /dotlessi /lslash /oe /scaron /zcaron 160 /Euro 164 /currency 166 Robert L. Zimdahl, in Fundamentals of Weed Science (Fifth Edition), 2018. The short-term treatment studies include hydroponic studies with whole immature plants (Hargroder and Rogers, 1974; Smith and Wilkinson, 1974; Maun and McLoed, 1978; Mangeot et al., 1979; Frear et al., 1981, 1982, 1983, 1985; Abusteit, 1983; Fedtke, 1983, 1986a, 1986b; Fedtke and Schmidt, 1983; Falb and Smith, 1984, 1987; Abusteit et al., 1985; Gawronski et al., 1985, 1986, 1987; Devlin et al., 1987; Smith et al., 1989; Davis et al., 1991), hydroponic studies with excised plant tissues (Schumacher, 1974; Frear et al., 1981, 1982, 1983, 1985; Gawronski et al., 1985; Fedtke, 1986b; Davis et al., 1991), and studies with plant cell cultures (Oswald et al., 1978; Abusteit, 1983; Fedtke and Schmidt, 1983; Davis et al., 1991). Rapid photodegradation of metribuzin required the presence of oxygen (or hydrogen peroxide), and the rate of photodegradation was slowed by more than an order of magnitude in the absence of oxygen (Muszkat et al., 1998). Continued photolysis resulted in degradation of these initial photoproducts, much of which involved the 1,1-dimethylethyl side chain, and eventually led to the formation of 6-azauracile and 6-azathymine, both of which are very stable photochemically. endobj Atrazine's low cost and broad spectrum weed control have made these fallow rotations profitable in areas where grain production otherwise would not be economically feasible. Because of its residual activity and broad spectrum of control, atrazine is one of the most effective herbicide alternatives applied early preplant. 10 0 obj Because of the unique nature of reproductive aging in female SD rats, the carcinogenic response in this strain is not considered relevant to humans. &YGt0|ikX-gYGcI9tN:NxWLibQWfqJr4i\_7_a\l R!hY3+?G\.-NKlIiUM.&Dn-t$^H$zm The triazines are popular in conservation tillage due to their consistent performance under a wide variety of environmental, soil, and surface crop residue conditions and their residual soil activity, which controls late-germinating weeds. As a result, it is imperative that we start clean at planting and begin with a good residual herbicide. Richard S. Fawcett, in The Triazine Herbicides, 2008. >> The problem here is that the metribuzin component is lowered to the point that a sensitive soybean variety will not be injured by the metribuzin, but in turn the rate is so low that the metribuzin provides marginal pigweed control. 2017-03-08T02:14:34+05:01 38 0 obj <> endobj 3 0 obj endstream In trials Ive conducted over the past several years, one herbicide consistently ranks at the top of the list for residual Palmer pigweed control and that is a full rate of metribuzin. << The major commercial symmetrical triazines are further divided into chloro-s-triazines: simazine, atrazine, propazine, cyanazine; the thiomethyl-s-triazines: ametryn, prometryn, terbutryn; and the methoxy-s-triazine prometon. Confidence in the consistent weed control provided by triazine herbicides has encouraged these farmers to make a major management change and has allowed them to reap the economic and environmental benefits of the crop production system. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. 9 0 obj endobj U6wWh QOkpT7$r n/ #&. Rgd]=XvW` j8Zax:/KAg /Name /Helv 2 0 obj /DR << In soybeans, PPO herbicides that are being applied at planting are Reflex and Valor. Now we have a reduced rate of each component and there is a wealth of recent research showing that reduced rates of herbicides contribute to resistance. Again this year, I will be screening all varieties placed in the Arkansas soybean variety testing trial along with a few additional varieties. >> >>
/Contents [10 0 R 11 0 R 12 0 R] As with most planting seasons, this one has been anything but normal. uuid:7d6732e4-dc75-4132-8891-cd9de2c12d42 Cyanazine contains a 2-cyano-isopropylamino-substituent at the 4-position on the ring. /PDFDocEncoding 8 0 R Increased use of metribuzin would most definitely help protect the PPO herbicides.
https://doi.org/10.1017/S0890037X00030232 Published online by Cambridge University Press Stage of growth and species mix of these early germinating weeds vary from year-to-year, depending on weather.
gmZro}6o}IIZg. Q}x^mwp8i2vDywPw2TzXPlr-_WBn2D!VMy'YOTo.ulmyjb+DSon9IuQY1UR4|(l|xC%"UQ`_L&ZR\){(xS)p$hZbUa~T3unRI?7]P$YKQ[A"l/ /Encoding 8 0 R >> These inhibitors of photosynthesis include the asymmetrical triazines or triazinones, such as metribuzin, and the symmetrical triazine herbicides. -pX6 lT!2;xHJ?4`e2O"L)b4vySRH AwaQhp@W9~X]&*gtZSU9=bqr % 69 0 obj
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Triazine herbicides are particularly well suited for conservation tillage because they provide foliar and residual control of a broad spectrum of weeds. Chemical Key Trade Name, Major Manufacturer, and Formulations for the Selected Triazines and Triazinone, Charles B. Breckenridge, Darrell D. Sumner, in The Triazine Herbicides, 2008. /Differences [24 /breve /caron /circumflex /dotaccent /hungarumlaut /ogonek /ring /tilde 39 Allan J. Cessna, in The Triazine Herbicides, 2008. Metribuzin is sold in more than 75 countries, with the top five being the United States, Brazil, Canada, China, and Germany. >> /F13 14 0 R endstream /ordmasculine 188 /onequarter /onehalf /threequarters 192 /Agrave /Aacute /Acircumflex /Atilde /Producer (ABBYY FineReader 9.0 Corporate Edition) /Tabs /S /XObject << Metribuzin was launched in 1970 by Bayer under the trade name Sencor and also is sold by DuPont under the trade name Lexone for control of certain broadleaf weeds and grassy weed species. /Length 1560 X2~>1}y&i3(/cIcNT9.*;X+ &*qF8(4I>hk={t9nM9]| application/pdfPesticide Product Label, Omni Brand Metribuzin 4SCUS EPA, Pesticide Product Label, Omni Brand Metribuzin 4SC,02/22/2018Pesticide Product Label, Omni Brand Metribuzin 4SCUS EPA,Office of Pesticide Programs I actually took a look at several products this past summer and when I applied metribuzin alone at the low rate contained within the premix, the result was utter failure on pigweed. 8 0 obj /Metadata 2 0 R Gonzlez, in Encyclopedia of Toxicology (Third Edition), 2014. stream
ABBYY FineReader 9.0 Corporate Edition Farm Progress is part of the Informa Markets Division of Informa PLC. vU-X,r Sh;>S HW]o#
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Z@@4}zPKrdywH{nu._WS_wponw6o]}+]n]I]$~}}GrH}wOC|s09?/G%>im`w,!eFDT0J]cD(Bef[F+u5)9p%2~g%VLu$/PKGIsiwZ/SLdzy3r'$i,35TxM.D>8op?;}rOCt!N} Table 66.1. /quotesingle 96 /grave 128 /bullet /dagger /daggerdbl /ellipsis /emdash /endash The major symmetrical triazines are further divided into chloro-s-triazines: including simazine, atrazine, terbuthylazine, propazine, cyanazine; the thiomethyl-s-triazines (also referred to as methylthiotriazines): ametryn, prometryn, terbutryn; and the methoxy-s-triazine: prometon. endobj /florin /fraction /guilsinglleft /guilsinglright /minus /perthousand /quotedblbase /quotedblleft /quotedblright /quoteleft Often, the need for a foliar nonselective herbicide, such as paraquat or glyphosate, is eliminated, as weeds are killed before or during emergence. The asymmetrical triazine, metribuzin, retains the triazine ring, but since the nitrogen atoms are unevenly spaced, aromaticity is maintained by the presence of the carbonyl group. x+ |
Farmers reluctant to change to conservation tillage consistently rank concern about weed control as their primary reason for not converting to conservation tillage. endstream In addition, weed infestations in sod can reduce tensile strength and cause problems in harvesting and handling. 
Weeds may germinate under crop residue and escape contact with herbicides as they emerge. Two triazinones act quite differently. >> There are likely three reasons for recommending a lower rate when applying two products together. >> This class of herbicides includes the asymmetrical triazines, Environmental Benefits of Triazine Use in Conservation Tillage. The symmetrical triazines (s-triazines) have a chlorine, sulfur, or oxygen atom at the 2-position of the ring and are usually substituted in the 4- and 6-positions with alkylamino-group (Fig. yQ!g!0w2X+4-f)u|>m6j{0f.Fn6&m=1v
&&FOiO/ x15?$.!C;Z4`U-p#n|7^e3d2e%o Early application allows more time for rains to occur before weed germination, reducing chances for dry-weather herbicide failure. If triazine herbicides were not available, major changes in weed control programs for conservation tillage would be necessary, increasing yield risk and uncertainty and hindering grower acceptance of conservation tillage. /F4 17 0 R %PDF-1.6 stream
The duration of these studies was usually measured in terms of weeks or months, and their purpose was to determine the nature of the terminal residues in crops in order to set pesticide residue tolerances. Not for further distribution unless allowed by the License or with the express written permission of Cambridge University Press. <>/Font<>>>/MediaBox[0.0 0.0 612.0 792.0]/StructParents 1/Annots 12 0 R/Rotate 0>> Metribuzin and its degradates (desaminometribuzin, desaminodiketometribuzin, and diketometribuzin) are persistent and mobile. Metribuzin products are primarily intended for industrial use and no unreasonable risks to humans or the environment have been detected. All rights reserved. /X1 13 0 R HML^3&K^u3\@om
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F %PDF-1.6 5 0 obj While many other herbicides have been developed for use in warm-season turfgrasses, the triazines are still an integral and economically important family of herbicides for homeowners, lawncare experts, sports field managers, golf course superintendents, sod producers, and other turfgrass specialists. The postemergence activity of atrazine provides control of small emerged weeds from no-till planting-time treatments, often eliminating the need for nonselective herbicides. >> https://doi.org/10.1017/S0890037X00030232 [x|^ Information on this is available at the University of Arkansas Web site. The other member of this group, carfentrazone-ethyl, applied in the range of 439g/ha, has proven to be very effective in corn, sorghum, rice, soybean, and small grains to control weeds resistant to the imidazolinone and sulfonylurea herbicides. Available in various concentrations (4%, 50%, 75%, etc.). Human exposure to metribuzin occurs through inhalation and ingestion, usually in agricultural settings but general population exposures are thought to be minimal. Figure 23.7. It is known for its efficiency and relatively low toxicity. Metribuzin products are primarily intended for industrial use and no unreasonable risks to humans or the environment have been detected. /Type /Font hb```f``a`a`c`@ r r&2Y23]e b`fg`
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/Kids [9 0 R] >> endobj /Annots [18 0 R] /Subtype /XML cjY)S*9~j-4nd. /Type /Pages Surface-applied herbicides require timely rainfall to incorporate them into the soil prior to weed germination. I routinely talk about the need for using multiple effective modes of action against pigweed or any other resistant-prone weed as a means of protecting herbicides against resistance. Timely rains after application often are more important in no-till systems than with tillage; weeds may have germinated (but not emerged) several days prior to planting and herbicide application, and thereby escape foliar nonselective herbicides. From: Encyclopedia of Toxicology (Third Edition), 2014, C.R. Photoproducts resulting from the photolysis (254 nm) of an aqueous solution of metribuzin. Conversion from conventional tillage to conservation tillage involves considerable operator learning and crop production risk.