• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.4
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• pp.285-290
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• 1998

aThis experiment was carried out to obtain the basic information on some factors affecting callus formation and plant regeneration in seed culture of orchardgrass. Varietal difference in callus growth and plant regeneration was obvious among four varieties of orchardgrass. "Amba" showed a relatively high capacity for plant regeneration. The $N_6$ medium was superior to MS and $B_5$ in callus formation and plant regeneration. The fresh weight of callus was promoted by the increase of dicamba concentration. However, the maximum frequency (30.0%) of plant regeneration was obtained from the callus formed in presence of 3 mg/L dicamba.

• Journal of Environmental Science International
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• v.28 no.8
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• pp.689-700
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• 2019

The adsorption and leaching characteristics of five ionic pesticides including four acidic pesticides (2,4-D, dicamba, MCPA, and MCPP) and one amphoteric pesticide (imazaquin) in agricultural soils were investigated. Soils around spring waters that were heavily affected by pesticide run-off and soils around wells considering the regional characteristics in Jeju Island were collected at 24 stations. The Freundlich constant, $K_F$ value, which is a measure of the adsorption capacity, decreased in the order of 2,4-D > MCPA > MCPP > dicamba > imazaquin. The adsorption capacity of these ionic pesticides decreased with increasing pH owing to the effects of ionization of pesticides and different ionizable functional groups of soils. The leaching of ionic pesticides in the soil column showed a reverse relationship with their adsorption in soils, namely, the ionic pesticides were leached more quickly for the pesticides with lower adsorption capacity. The groundwater contamination potential of the ionic pesticides was evaluated in the order of imazaquin > MCPA > MCPP > dicamba > 2.4-D according to the groundwater ubiquity score based on soil Koc and the half-life of the pesticide.

• Korean Journal of Environmental Agriculture
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• v.14 no.1
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• pp.45-54
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• 1995

esters of the acid analytes were synthesized using $H_2SO_4$ as the catalyst. Efficiency of derivatization and instrumental molecular-response were compared with herbicides methylated with $BF_3-methanol$(14% W/V), $H_2SO_4-methanol$(33% V/V), and diazomethane. The molecular integrity of TFE-2,4-D, TFE-dicamba, and TFE-mecoprop, in the mixture, was confirmed by the GC/MSD method. The TFE-Esterification efficiency was maximized by adjusting the volume of $H_2SO_4$ the reaction time, and temperature. Optimal efficiency for the herbicide mixture was obtained by adding 1 ml of $H_2SO_4$ and 1 ml of TFE to the dried sample and allowing the reaction to proceed at $22^{\circ}C$ for 8 hr or using 0.5 ml $H_2SO_4$ and 1 ml of TFE at $60^{\circ}C$. For 120 min increasing the temperature and decreasing the reaction time were required for maximum esterification efficiency. The sensitivity of the GC/ECD to the TFE esters was about $2{\sim}20$ times greater than that to the methyl ester derivatives. The herbicides were extracted and esterified to TFE derivatives simultaneously from soil leachates previously spiked with the analytes. Herbicide recovery, peak resolution, and detector sensitivity were excellent without using column cleanup procedures.

• Asian Journal of Turfgrass Science
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• v.10 no.3
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• pp.263-270
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• 1996

This experiment was conducted to investigate the loss of various herbicides by means of vola-tility from the turfgrass field and the hare ground with the different soil moisture contents and temperatures. Different herbicides were applied at the rates of 375 g a.i. /l0a of pendimethalin,250 g a.i. /l0a of napropamide, and 96.4 g a.i. /l0a of dicamba with 200 \ulcorner/10a of spray volume in the turfgrass(Zoysia japonica cut off 5cm) grown in pots(265.8 $cm^2$) and bared soil. The pots were placed in the growth chamber with 10,000 lux of light intensity(12h per day) at 25 and 35˚C for 7days. Amberlite XAD polymeric resin(20/50 mesh) was used as sampling media for herbicide airborne residues. Air flow was maintained at 10 \ulcorner /min by vacuum pump regulated with a factory calibrated flow meter. Herbicide airborne residues were extracted from the XAD resin with 300 ml of 1:1 acetone and hexane. The extracts were concentrated by rotary evaporation at 35˚C and dissolved in 1 ml MeCN for HPLC analysis. The airborne losses of the herbicide applied in the turfgrass and bare soil increased as the temperature and soil moisture contents were increased, regardless of the kinds of herbicide. Higher airborne residues was observed in the turfgrass pots than the bare soil pots. Pendimethalin and dicamba with higher vapor pressure gave rise to the increased loss of airborne herbicides, showing that 6.26 and 6.4% of average airborne loss in pendimethalin and dicamba, respectively, compared to 0.56% in napropamide. The amount of airborne losses in turfgrass was highest at one day after application and then a declined trend was observed as the time was prolonged. Key words. Herbicides, Turfgrass field, Bare ground, Volatility.

• Asian Journal of Turfgrass Science
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• v.21 no.1
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• pp.69-79
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• 2007

Incorporating herbicides application into a fertilization program has several benefits including saving time and reducing traffics on the lawn. Premixed products of fertilizers and herbicides are commonly known as Weed & Feed in the lawn-care industry. To compare Weed & Feed with separate applications of fertilizers and herbicides on a Kentucky bluegrass (Poa pratensis L.) lawn, a Weed & Feed 28-3-3, containing 0.64% 2,4-D, 0.31% MCPP, and 0.03% dicamba of active ingredients, was used in this study. The first application was in May, with the second in June or Sept. Herbicides in forms of 2,4-D (LV-4, 4EC), MCPP (4EC), and dicamba (Clarity, 4EC) were applied at rates equal to the amounts in Weed & Feed or at half of the rates. The dominant weed in both locations was common dandelion (Taraxacum officinale Weber.) in 2005 and 2004. A secondary weed was Canada thistle (Cirsium arvense (L.) Scop.) in 2004 and broadleaf plantain (Plantago major L.) in 2005. When applied in May and June, fertilizer plus full rate of herbicides treatment achieved 112.3 and 83.7 days of acceptable turf quality in 2004 and 2005, respectively. During the same period, Weed & Feed resulted in 58.7 and 24.3 days of acceptable turf quality, respectively. Our study showed that Weed & Feed was generally as effective in weed control as the same amount of fertilizer plus half rates of herbicides sprayed although results may vary due to the timing of application. Fertilizer plus full rates of herbicides provided the same or better results of weed control than Weed & Feed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.357-362
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• 1997

This study was carried out to investigate the effects of herbicide treatment and seeding method on the forage yield, weed control, and persistency in the Artemisia princeps dominated pasture. It was arranged as a randomized block design with seven treatments(\circled1 oversowing(control),\circled2 glyphosate 4 ${\ell}$/ha + oveysowing a \circled3glyphosate 4 ${\ell}$/ha + chiselreseeding, \circled4 paraquat dichloride 3 ${\ell}$/ha + oversowing,\circled5 paraquat dichloride 3 ${\ell}$/ha + chiselreseeding, \circled6 dicamba 4 ${\ell}$/ha + oversowing and \circled7 dicamba 4 ${\ell}$/ha + chiselreseeding), and conducted at National Livestock Research Institute in Suwon from June, 1985 to October, 1987. In the Artemisia princeps dominated pasture, the treatments of glyphosate 4 ${\ell}$/ha before oversowipg or chisel reseeding controlled 80.7-83.3% of the Artemisia princeps, and for two years the average dry weight of Artemisiaprinceps greatly decreased, but dry matter(DM) yield of forage increased 57-96% than that pf control. In the herbicide treatments, the average DM yield of forage in the plots with chisel r e d i n g was significantly higher when compared to oversowing. The results in this study indicated that herbicide treatment was effective for the control of Artemisiaprinceps, and good renovation of grassland and higher DM yield of forage could be obtained by application of glyphosate.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10b
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• pp.21-21
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• 2003

An efficient plant regeneration system was developed for Hordeum vulgare L. cv Baegdong - an important Korean cultivar. The protocol was based on a series of experiments involving the sizes of mature embryos and the culture media. The embryo size is found to be critical for the establishment of embryogenic callus. Embryos of 1.1-1.5 mm size showed a much higher ability to produce embryogenic callus capable of regenerating green plants. The auxins picloram and dicamba proved effective in inducing callus from mature embryos. 2.5 mg $I^{-1}$ dicamba and 4.0 mg $I^{-1}$ picloram in Murashige and Skoog's (MS) medium was optimum for the induction of primary callus. The induced primary callus was loose and friable which ultimately developed into creamy white and compact callus after transferring into the fresh medium. Multiple shoots were induced in the MS medium supplemented with 6.0 g $I^{-1}$ maltose, 20 mg $I^{-1}$ sorbitol, 0.5 mg $I^{-1}$ 2,4-D and 1.0 mg $I^{-1}$ kinetin and the rate was 6.5 shoots per embryo. Regenerated plants were hardy and developed roots rapidly in the medium containing 0.2 $I^{-1}$ IBA. This efficient plant regeneration system provides a foundation for generating transgenic plants of this important barley cultivar.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10a
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• pp.59-67
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• 2003

An efficient plant regeneration system was developed for Hordeum vulgare L. cv Baegdong - an important Korean cultivar. The protocol was based on a series of experiments involving the sizes of mature embryos and the culture media. The embryo size is found to be critical for the establishment of embryogenic callus. Embryos of 1.1-1.5 mm size showed a much higher ability to produce embryogenic callus capable of regenerating green plants. The auxins picloram and dicamba proved effective in inducing callus from mature embryos. $2.5\;m;I^{-1}$ dicamba and $4.0\;mg\;I^{-1}$ picloram in Murashige and Skoog's (MS) medium was optimum for the induction of primary callus. The induced primary callus was loose and friable which ultimately developed into creamy white and compact callus after transferring into the fresh medium. Multiple shoots were induced in the MS medium supplemented with $6.0\;g\;I^{-1}$ maltose, $20\;mg\;I^{-1}$ sorbitol, $0.5\;mg\;I^{-1}$ 2, 4-D and $1.0\;mg\;I^{-1}$ kinetin and the rate was 6.5 shoots per embryo. Regenerated plants were hardy and developed roots rapidly in the medium containing $0.2\;I^{-1}$ IBA. This efficient plant regeneration system provides a foundation for generating transgenic plants of this important barley cultivar.

• Korean Journal of Plant Resources
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• v.7 no.2
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• pp.171-175
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• 1994

The effects of medium, hormones, and PFP on the proliferation of red callus in leaf tissue cultures of Garden orach(Atriplex hortensis L.) was investigated. As a result,88% of leaf tissues formed eallus on MS nledium containing 2mg/$\ell$ 2,4-D. Fresh weight of callus was higher on MS medium than on Bsand NN media. It was also found that 2, 4-D was more effective than Dicamba and Picloram. The op-timum concentrations of hormones for callus proliferation depended on culture media. Isolated red cal-lus grew markedly both on MS medium supplemented with 1-2mg/$\ell$ 2, 4-D and Bs medium contain-ing 2-4111g/$\ell$ 2,4D. Callus proliferated on B5 and NN media containing Dicabma Img/$\ell$ as well as onthe same media containing 2mg/$\ell$ Picioram. The addition of PFP concentrations of 2, 5, and 40mg/ $\ell$rcspectiely to culture medium caused increase of callus fresh weight, especially under light condition.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.151-154
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• 2003

This study was conducted to determine the optimal concentrations of plant hormones (2,4-D, picloram, dicamba, NAA, kinetin) and the suitable explants among seeds, hypocotyl, and cotyledons on calls formation and plant regeneration of stevia(Stevia rebaudiana Bertoni). The frequency of cellus formation was higher in the young leaf-explants then the older ones, and in the seeds then the hypocotyls and cotyledons on MS medium with 1mg/L 2,4-D. After transfer of seed-derived stevia callus producing embryogenic callus on plant-regeneration medium, the frequency of plant regeneration from callus was 23.8% in MS medium with 1mg/L NAA and 3mg/L kinetin.