scholarly journals 695 Weed Control in Minor Crops After the Loss of Methyl Bromide

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 519A-519
Author(s):  
Chad Hutchinson
Keyword(s):  
Weed Control ◽  
Pest Control ◽  
Broad Spectrum ◽  
Methyl Bromide ◽  
Control Strategies ◽  
The United States ◽  
Field Application ◽  
Multiple Control ◽  
Yellow Nutsedge ◽  
Minor Crops

The economics of pesticide production and registration has limited the number of pesticides registered for use in minor crops relative to agronomic crops. Current regulations such as the Food Quality Protection Act may further reduce the number of efficacious compounds registered for use on minor crops. Traditionally, the lack of registered pesticides for minor crops has been offset by soil fumigation. However, methyl bromide use is scheduled for phase-out in the United States by 2005, leaving a pest control vacuum in some crops. Loss of methyl bromide has stimulated research into the use of other soil fumigants for weed control. Methyl bromide, methyl iodide, propargyl bromide, 1,3-dichloropropene, and metham sodium have been tested alone and in combination with chloropicrin in laboratory experiments to determine their efficacy against Cyperus esculentus L (yellow nutsedge) tubers. All the fumigants controlled nutsedge equal to or better than methyl bromide and resulted in synergistic control when combined with chloropicrin. Although excellent weed control can be achieved with all the fumigants in the laboratory, weed control in the field with the same fumigant may result in poor or no control. Further research is necessary to optimize the field application of the remaining fumigants to maximize pest control. In the near future, to achieve the broad-spectrum pest control obtained with methyl bromide, growers will need to rely on multiple control strategies. The most promising replacement program for broad-spectrum pest control includes dichloropropene/chloropicrin fumigation followed by a herbicide program or mechanical weed control. To control problem weeds that are not controlled with the in-season herbicide program, a chemical fallow program should be instituted in the off-season to reduce weed pressure during the cropping season.

Herbicidal Performance of Phenyl Isothiocyanate in Polyethylene-Mulched Bell Pepper

2012 ◽  
Vol 26 (4) ◽  
pp. 763-768 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur
Keyword(s):  
Weed Control ◽  
Methyl Bromide ◽  
The United States ◽  
Palmer Amaranth ◽  
Bell Pepper ◽  
Phenyl Isothiocyanate ◽  
Marketable Yield ◽  
Suitable Alternative ◽  
Yellow Nutsedge ◽  
Large Crabgrass

Methyl bromide is a common fumigant for effective weed control in polyethylene-mulched vegetable crops. However, the ban on methyl bromide in the United States has created a need to find a suitable alternative. This study investigated the herbicidal efficacy of phenyl isothiocyanate (ITC) as a methyl bromide alternative for weed control in polyethylene-mulched bell pepper during 2006 and 2007. Six rates of phenyl ITC (0, 15, 75, 150, 750, 1,500 kg ha−1) under low-density polyethylene (LDPE) or virtually impermeable film (VIF) mulch were tested against yellow nutsedge, Palmer amaranth, and large crabgrass. Additionally, a standard treatment of methyl bromide/chloropicrin (67 : 33%) at 390 kg ha−1under LDPE mulch was included for comparison. VIF mulch provided no advantage over LDPE mulch in either improving weed control or marketable yield in bell pepper. Unacceptable pepper injury (≥ 60%) occurred at the highest phenyl ITC rate of 1,500 kg ha−1at 2 WATP in both years, regardless of mulch type. Higher bell pepper injury was observed in 2006 (≥ 36%) than in 2007 (≤ 11%) at 750 kg ha−1of phenyl ITC. The lower injury in 2007 could be attributed to aeration of beds 48 h prior to transplanting. Regardless of mulch type, phenyl ITC at 2,071 (± 197) and 1,655 (± 309) kg ha−1was required to control yellow nutsedge, Palmer amaranth, and large crabgrass equivalent to methyl bromide in 2006 and 2007, respectively. Bell pepper marketable yield at all rates of phenyl ITC was lower than methyl bromide in 2006. In contrast, marketable yield in phenyl ITC at 750–kg ha−1was equivalent to methyl bromide in 2007. It is concluded that phenyl ITC should be applied at least 4.2 times higher rate than methyl bromide for effective weed control, and bed aeration is required to minimize crop injury and yield loss. Additional research is needed to test phenyl ITC in combination with other weed control strategies to obtain effective weed control with acceptable crop safety.

Metam Sodium Combined with Chloropicrin as an Alternative to Methyl Bromide Fumigation for Tomato

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 525b-525 ◽  
Author(s):  
S.J. Locascio ◽  
D.W. Dickson
Keyword(s):  
United States ◽  
Lycopersicon Esculentum ◽  
Pest Control ◽  
Methyl Bromide ◽  
Soil Fungi ◽  
Good Control ◽  
The United States ◽  
Metam Sodium ◽  
Additional Water ◽  
Phase Out

In past work, dichloropropene + 17% Pic (1,3-D + Pic) at 327 L·ha–1 plus pebulate provided good control of nematode, soil fungi, and nutsedge in mulched tomato (Lycopersicon esculentum Mill.) and is considered the best alternative for methyl bromide (MBr) + chloropicrin (Pic), which is scheduled for phase-out in the United States by Jan. 2001. Metam-sodium did not provide acceptable pest control. In the present study, metam-Na (295 L·ha–1 combined with Pic (168 kg·ha–1) + 4.5 kg·ha–1 pebulate, and 1,3-D + 35% Pic at 168 and 225 L·ha–1 + pebulate were compared to MBr-Pic (98-2% at 345 kg·ha–1 and 67-33% at 505 kg·ha–1). Fumigants were injected into the bed except metam-Na and pebulate were surface-applied and incorporated and drip tubing and mulch were applied. Marketable yields with MBr-Pic, 225 L·ha–1 1,3-D + Pic, and metam-Na + Pic were higher than with the check. Yields with metam-Na alone or with additional water before transplanting were similar to the check. Nutsedge was controlled with MBr-Pic and all treatments with pebulate. Nematode root-gall ratings were high on tomato grown without fumigants (8.9 rating on a scale of 0 to 10 with 0 = no galling), low with MBr-Pic (0.33), and intermediate with all other treatments (2.2 to 5.5) except with 168 L·ha–1 1-3-D + Pic (8.3). This study indicates that metam-Na + Pic + pebulate also is a possible alternative to MBr-Pic for tomato.

scholarly journals Fumigant Alternatives to Methyl Bromide for Polyethylene-mulched

HortScience ◽  
1997 ◽  
Vol 32 (7) ◽  
pp. 1208-1211 ◽  
Author(s):  
Salvadore J. Locascio ◽  
James P. Gilreath ◽  
D.W. Dickson ◽  
Thomas A. Kucharek ◽  
J.P. Jones ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Methyl Bromide ◽  
Environmental Protection Agency ◽  
Soil Fungi ◽  
Stratospheric Ozone ◽  
Tomato Fruit ◽  
The United States ◽  
Soil Fumigation ◽  
Tomato Production ◽  
Metam Sodium

Tomato (Lycopersicon esculentum Mill.) was grown to evaluate various chemicals as possible alternatives to methyl bromide soil fumigation. Due to a combination of weeds, nematodes, and soil fungi, the use of a broad-spectrum fumigant has been essential for economical tomato production in Florida. Methyl bromide (MBr) and combinations of MBr with chloropicrin (Pic) are the fumigants of choice for most growers using polyethylene mulch culture. In 1991, MBr was allegedly associated with stratospheric ozone depletion. The U.S. Environmental Protection Agency has since mandated a phaseout of MBr for soil fumigation in the United States by the year 2001. At three locations in Florida, alternative soil fumigants were evaluated, including soil injected 98% MBr—2% Pic at 450 kg·ha-1, 67% MBr—33% Pic (390 kg·ha-1), Pic (390 kg·ha-1), dichloropropene + 17% Pic (1,3-D + Pic) at 327 L·ha-1, and metam-sodium (935 L·ha-1). Also, metam-sodium and tetrathiocarbonate (1870 L·ha-1) were applied by drip irrigation. Dazomet (450 kg·ha-1) was surface applied and soil incorporated. Pebulate (4.5 kg·ha-1) was soil incorporated with some treatments. Pic and 1,3-D + Pic treatments provided good to moderate control of nematodes and soil fungi except in one of the six studies, in which nematode control with 1,3-D was moderate to poor. Nutsedge densities were suppressed by addition of pebulate. Tomato fruit yields with 1,3-D + Pic + pebulate and with Pic + pebulate at the three sites ranged from 85% to 114%, 60% to 95%, and l01% to 119%, respectively, of that obtained with MBr treatments. Pest control and crop yield were lower with treatments other than the above pebulate-containing or MBr-containing treatments. These studies indicate that no one alternative pesticide can provide the consistent broad-spectrum control provided by MBr. Chemical names used: trichloronitromethane (chloropicrin); 1,3-dichloropropene (1,3-D); sodium N-methyldithiocarbamate (metam-sodium); sodium tetrathiocarbonate (tetrathiocarbonate); 3,5-dimethyl-(2H)-tetrahydro-l,3,5-thiadiazine-2-thione (dazomet); S-propyl butyl(ethyl)thiocarbamate (pebulate).

Allyl Isothiocyanate and Metham Sodium as Methyl Bromide Alternatives for Weed Control in Plasticulture Tomato

2014 ◽  
Vol 28 (2) ◽  
pp. 377-384 ◽  
Author(s):  
Pratap Devkota ◽  
Jason K. Norsworthy
Keyword(s):  
Weed Control ◽  
Methyl Bromide ◽  
Allyl Isothiocyanate ◽  
Palmer Amaranth ◽  
Tomato Production ◽  
Tomato Plants ◽  
Yellow Nutsedge ◽  
Tomato Yield ◽  
Metham Sodium ◽  
Large Crabgrass

Isothiocyanates (ITCs) were evaluated as an alternative to methyl bromide (MeBr) for control of Palmer amaranth, large crabgrass, and yellow nutsedge; reduction of tuber density; and increase in marketable tomato yield in low density polyethylene (LDPE)-mulched tomato production. Allyl ITC was applied at 450, 600, and 750 kg ai ha−1; metham sodium (methyl ITC generator) was applied at 180, 270, and 360 kg ai ha−1; and MeBr plus chloropicrin (mixture of MeBr and chloropicrin at 67 : 33%, respectively) was applied at 390 kg ai ha−1. A nontreated weedy check was included for comparison. There was no injury to tomato plants following allyl ITC, metham sodium, or MeBr application. Allyl ITC at 750 kg ha−1or metham sodium at 360 kg ha−1controlled Palmer amaranth ≥ 79%, large crabgrass ≥ 76%, and yellow nutsedge ≥ 80% and was comparable to the weed control with MeBr. Highest rates of allyl ITC and metham sodium reduced yellow nutsedge tuber density (≤ 76 tubers m−2) comparable to the MeBr application. Total marketable tomato yield was ≥ 31.6 t ha−1in plots treated with allyl ITC at 750 kg ha−1or metham sodium at 360 kg ha−1. Marketable tomato yield from the highest rate of allyl ITC or metham sodium were similar to the yield (38.2 t ha−1) with MeBr treatment. Therefore, allyl ITC at 750 kg ha−1and metham sodium at 360 kg ha−1are effective alternatives to MeBr for Palmer amaranth, large crabgrass, and yellow nutsedge control in LDPE-mulched tomato.

Interaction BetweenColletotrichum coccodesand Thidiazuron for Control of Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1987 ◽  
Vol 35 (3) ◽  
pp. 377-383 ◽  
Author(s):  
L. A. Wymore ◽  
A. K. Watson ◽  
A. R. Gotlieb
Keyword(s):  
Weed Control ◽  
Normal Development ◽  
Control Strategies ◽  
Field Application ◽  
Abutilon Theophrasti ◽  
Effective Control ◽  
Application Rates ◽  
Bud Growth ◽  
High Concentrations ◽  
Axillary Bud Growth

Velvetleaf (Abutilon theophrastiMedik. # ABUTH) is difficult to control with existing weed control strategies. Some measure of control can be obtained with a fungus,Colletotrichum coccodes(Wallr.) Hughes, used as a bioherbicide, but when the bioherbicide application was combined with the plant growth regulator thidiazuron (N-phenyl-N′-1,2,3-thidiazol-5-yl-urea), weed control was substantially improved. Thidiazuron alone interfered with normal development of velvetleaf, causing stunting and initiation of axillary bud growth. Tank mix applications ofC. coccodesand thidiazuron acted synergistically to increase velvetleaf mortality. WhenC. coccodeswas applied 10 days after thidiazuron as a split application, weed control was less than for tank mix applications. However, two applications ofC. coccodesplus thidiazuron were more effective than equivalent single tank mix applications. Under laboratory conditions, high concentrations of thidiazuron (2× field application rates) inhibited growth ofC. coccodes, but at field application rates thidiazuron did not reduce disease development. Combinations of thidiazuron andC. coccodesmay provide effective control of velvetleaf in the field.

Efficacy and Economics of Herbicide Programs Compared to Methyl Bromide for Weed Control in Polyethylene-Mulched Bell Pepper

2015 ◽  
Vol 29 (2) ◽  
pp. 284-297 ◽  
Author(s):  
Pratap Devkota ◽  
Jason K. Norsworthy ◽  
Ron Rainey
Keyword(s):  
Weed Control ◽  
Methyl Bromide ◽  
Weed Management ◽  
Economic Loss ◽  
Bell Pepper ◽  
Yellow Nutsedge ◽  
Net Profit ◽  
Potential Alternative ◽  
Hand Weeding ◽  
Herbicide Programs

In the absence of an effective alternative to methyl bromide (MeBr), weeds cause a significant economic loss in bell pepper production. A study was conducted to evaluate the efficacy and economics of PRE followed by (fb) POST-directed (POST-DIR) herbicide programs compared with MeBr for weed control in low-density polyethylene (LDPE) mulched bell pepper production. Imazosulfuron at 0.112, 0.224, and 0.336 kg ai ha−1andS-metolachlor at 1.6 kg ai ha−1were PRE-applied fb POST-DIR applied mixture of trifloxysulfuron + halosulfuron at 0.008 and 0.027 kg ai ha−1, respectively, at 4 wk after transplanting (WATP). The standard MeBr treatment (67 and 33% mixture of MeBr + chloropicrin) was applied at 390 kg ai ha−1. In addition, a weed-free (hand weeding) and a non-treated control were used for comparison.S-metolachlor-containing herbicide program controlled Palmer amaranth ≥ 90%, large crabgrass ≥ 78%, and yellow nutsedge ≥ 90%, which were comparable to MeBr. After POST-DIR herbicide application, bell pepper was injured ≥ 17% with theS-metolachlor-containing herbicide program at 6 WATP; however, the crop later recovered. Marketable bell pepper yield in plots treated withS-metolachlor (≥ 29.9 ton ha−1) was comparable to those treated with MeBr. Economic evaluation of the imazosulfuron herbicide programs demonstrated the loss of ≥ $7,300 ha−1. Conversely, theS-metolachlor-containing herbicide program was profitable with a net return of $9,912 ha−1. In addition, theS-metolachlor herbicide program generated a net profit of $173 ha−1compared to the MeBr application. Therefore, PRE-appliedS-metolachlor fb POST-DIR applied trifloxysulfuron + halosulfuron is a potential alternative to MeBr for weed management in LDPE-mulched bell pepper production given the weed spectrum evaluated in this study.

Effect of Drip-Applied Metam-Sodium andS-Metolachlor on Yellow Nutsedge and Common Purslane in Polyethylene-Mulched Bell Pepper and Tomato

2017 ◽  
Vol 31 (3) ◽  
pp. 421-429 ◽  
Author(s):  
Daniel M. Dayton ◽  
Sushila Chaudhari ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Greg W. Hoyt
Keyword(s):  
Weed Control ◽  
Methyl Bromide ◽  
Drip Irrigation ◽  
Field Studies ◽  
Bell Pepper ◽  
Growth Responses ◽  
Metam Sodium ◽  
Yellow Nutsedge ◽  
Tomato Yield ◽  
Common Purslane

Field studies were conducted to determine the effect of metam sodium andS-metolachlor applied through drip irrigation on yellow nutsedge, common purslane, bell pepper, and tomato (injury and yield) in plasticulture. Treatments consisted of weed-free, weedy,S-metolachlor alone at 0.85 kg ha-1, methyl bromide, metam sodium (43, 86, 176, and 358 kg ai ha–1) alone, and metam sodium (43, 86, 176, and 358 kg ai ha–1) followed byS-metolachlor at 0.85 kg ha–1. Metam sodium andS-metolachlor was applied preplant 2 wk before and 2 wk after transplanting (WAT) through drip irrigation, respectively. No injury was observed to bell pepper and tomato from metam sodium alone, or metam sodium fbS-metolachlor treatments. With the exception of yellow nutsedge density 15 WAT in bell pepper, herbicide program did not influence yellow nutsedge and common purslane density at 4 and 6 WAT and bell pepper and tomato yield. At 15 WAT, yellow nutsedge density was lower in treatments that received metam sodium fbS-metolachlor compared to those treatments that only received metam sodium. Drip-applied metam sodium at 176 and 358 kg ha–1in both bell pepper and tomato provided similar control of common purslane, and yellow nutsedge, produced comparable yields, and failed to elicit any negative crop growth responses when compared to MeBr. In conclusion, metam sodium at 176 and 358 kg ha–1fbS-metolachlor 0.85 kg ha–1is an effective MeBr alternative for season long weed control in plasticulture bell pepper and tomato.

scholarly journals Determining the Microwave Radiations Exposure Level Needed for Weed Control Using a Stationary and Running Belt Microwave Radiations Applicator System1

2017 ◽  
Vol 35 (2) ◽  
pp. 58-65
Author(s):  
Aman Rana ◽  
Jeffrey F. Derr
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Control Strategies ◽  
Ambrosia Artemisiifolia ◽  
Prototype System ◽  
Exposure Level ◽  
Stationary Mode ◽  
Common Ragweed ◽  
Yellow Nutsedge ◽  
Belt System

Abstract There is a demand for nonchemical weed control strategies, with microwave radiations one possible option. Accurately measuring a weed's exposure level to microwave radiations is a challenge when there is a gap between when electricity is applied to the magnetron and actual production of microwave radiations. This gap causes an error in the calculation of actual energy needed for weed management. Any misinterpretation over-estimates the required energy load, adversely affecting the perceived value of the technology. Studies were conducted to eliminate the existing lag period. A running belt prototype was built for this purpose using two magnetrons producing 900 watt each installed on a treadmill with a power supply. There was significant improvement in the precision for calculations of total energy required for weed control. These anatomically diverse weeds showed more uniform thermal injuries and greater control using the running belt prototype system than a stationary unit. The LD50 for broadleaf weeds treated with microwave radiations using the running belt system ranged from 31.2 joules.cm−2 for common ragweed (Ambrosia artemisiifolia L.) to 36.8 joules.cm−2 for pitted morningglory (Ipomoea lacunosa L.). In comparison, treatment of weeds with microwave radiations using the stationary mode system resulted in a range of LD50 values of 64.5 joules.cm−2 for common ragweed to 155.1 joules.cm−2 for white clover (Trifolium repens L.). Similarly, the LD50 values for grasses treated with microwave radiations using the running belt system ranged from 34.3 for dallisgrass (Paspalum dilatatum Poir.) to 69.5 joules.cm−2 for southern crabgrass [Digitaria ciliaris (Retz.) Koeler]); in comparison, the range in LD50 values for grasses treated with stationary system was 136.1 to 182 joules.cm−2. The LD50 values for sedges treated with microwave radiations using the running belt system ranged from 29.2 joules.cm−2 for yellow nutsedge (Cyperus esculentus L.) to 78.1 joules.cm−2 for fragrant flatsedge (Cyperus odoratus L.); in comparison, the range in LD50 values for the stationary mode system was 119.4 joules.cm−2 for fragrant flatsedge to 145.9 joules.cm−2 for yellow nutsedge. Index words: Nonchemical control, weed control, efficacy, prototype, weed management.

Allyl Isothiocyanate as a Methyl Bromide Alternative for Weed Management in Polyethylene-Mulched Tomato

2012 ◽  
Vol 26 (3) ◽  
pp. 449-454 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur
Keyword(s):  
Weed Control ◽  
Methyl Bromide ◽  
Weed Management ◽  
Field Experiments ◽  
Allyl Isothiocyanate ◽  
The United States ◽  
Plastic Mulch ◽  
Marketable Yield ◽  
Tomato Production ◽  
Tomato Yield

Methyl bromide has been widely used for weed control in polyethylene-mulched tomato production. With the phaseout of methyl bromide in the United States, an effective alternative is needed. Field experiments were conducted in 2007 and 2009 to determine if allyl isothiocyanate (ITC) would provide substantive weed control in tomato along with crop tolerance under low-density polyethylene (LDPE) and virtually impermeable film (VIF) mulch. Treatment factors included two mulch types (LDPE and VIF) and six rates of allyl ITC (0, 15, 75, 150, 750, 1,500 kg ha−1). A standard treatment of methyl bromide : chloropicrin (67 : 33%) at 390 kg ha−1under LDPE mulch was also established. Allyl ITC was broadcast applied and incorporated in soil before forming raised beds and laying plastic mulch. Tomatoes were transplanted 3 wk after applying allyl ITC or methyl bromide treatments. Tomato injury was ≤ 8% in all treatments at 2 wk after transplanting (WATP). Allyl ITC at 913 (± 191) kg ha−1was required to control yellow nutsedge, Palmer amaranth, and large crabgrass equivalent to methyl bromide at 6 WATP and maintain marketable tomato yield equivalent to methyl bromide treatment. VIF mulch was not effective in increasing weed control or improving the marketable yield of tomato over LDPE mulch. This research demonstrates that allyl ITC under an LDPE mulch can have a practical application for weed control in polyethylene-mulched tomato in the absence of methyl bromide.

Comparison of the Herbicidal Activity of Phenyl Isothiocyanate with Methyl Bromide in Polyethylene-Mulched Tomato

2012 ◽  
Vol 26 (4) ◽  
pp. 666-672 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur
Keyword(s):  
Weed Control ◽  
Methyl Bromide ◽  
Field Experiments ◽  
Herbicidal Activity ◽  
Phenyl Isothiocyanate ◽  
Plastic Mulch ◽  
Marketable Yield ◽  
Yellow Nutsedge ◽  
Standard Rate ◽  
Control Equivalent

Field experiments were conducted in 2006 and 2007 to evaluate the herbicidal activity of phenyl isothiocyanate (ITC) on yellow nutsedge, Palmer amaranth, and large crabgrass in tomato grown on two polyethylene-mulched types. Treatments included two mulch types (low density polyethylene [LDPE] mulch and virtually impermeable film [VIF] mulch) and phenyl ITC at 0, 15, 75, 150, 750, and 1,500 kg ha−1. A standard rate of methyl bromide/chloropicrin (67 : 33%) at 390 kg ha−1under LDPE mulch was included for comparison. Regardless of mulch type, phenyl ITC at 1,452 (±133) and 1,719 (±426) kg ha−1was required for broad-spectrum weed control equivalent to methyl bromide in 2006 and 2007, respectively. Tomato injury was ≥ 44% at the highest phenyl ITC rate of 1,500 kg ha−1at 2 wk after transplanting (WATP) both years, irrespective of mulch type. Greater crop injury was observed from 750 kg ha−1of phenyl ITC in 2006 (≥ 27%) than in 2007 (≤ 10%). The greater injury in 2006 was attributed to a higher phenyl ITC concentration because holes in the plastic mulch for transplanting were punched at the time of transplanting in 2006; whereas, in 2007 holes were punched 2 d before transplanting, allowing 2 d of aeration before transplanting. Tomato marketable yield at all rates of phenyl ITC was lower than with methyl bromide in 2006. However, in 2007, marketable yield in plots treated with phenyl ITC at 750 kg ha−1was equivalent to methyl bromide. Overall, VIF mulch was no more effective than LDPE mulch at increasing weed control or improving the marketable yield of tomato either year.

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