In this work,a comparative study of three frequently employed modification techniques to g-C_(3)N_(4)(CN)nanosheets for the photocatalytic degradation of metribuzin(MET)under visible-light irradiation has been carried...In this work,a comparative study of three frequently employed modification techniques to g-C_(3)N_(4)(CN)nanosheets for the photocatalytic degradation of metribuzin(MET)under visible-light irradiation has been carried out in detail.The modification methods were coupling TiO_(2)nanoparticles(TO)as electron acceptors,nano-sized Fe_(2)O_(3)(FO)to construct a Z-scheme nanocomposite,and phosphate(HP)modification to promote O_(2)adsorption.The steady-state and transient-state surface photovoltage spectra and transient photoluminescence(PL)spectra confirmed that all the three modification techniques enhanced the charge separation with prolonged lifetimes and presented degradation activities in the order of TO/CN[FO/CN[HP/CN.The TO/CN nanocomposite showed the highest photocatalytic activity for MET degradation,with a sixfold higher rate than bulk CN.Liquid chromatography–tandem mass spectrometry and radical trapping experiments indicated that the increased activity was related to the synergetic effect of two radicals(·O^(2-) and ·OH)involved in the photocatalytic degradation pathway,which was different from the·OH radical-dominated pathway of bulk CN.This work reveals the importance of charge separation and the influence of the radical pathway and provides guidance for the design of high-efficiency photocatalysts.展开更多
The objective of this research was to evaluate the efficacy of various pre-emergence (PRE) and post-emergence (POST) herbicides for the control of volunteer adzuki bean (Vigna angularis (Willd.) Ohwi & Ohashi) in ...The objective of this research was to evaluate the efficacy of various pre-emergence (PRE) and post-emergence (POST) herbicides for the control of volunteer adzuki bean (Vigna angularis (Willd.) Ohwi & Ohashi) in soybean (Glycine max L.). Trials were conducted at two locations in 2005, 2006, 2007, and 2009. Experiments were arranged in a randomized complete block design with either five PRE or nine POST herbicides. Volunteer adzuki bean interference in soybean resulted in yield loss of up to 25%. Cloransulam-methyl, linuron, metribuzin, flumetsulam, and imazethapyr applied PRE provided up to 6, 24, 14, 8, and 0% control, respectively at 8 weeks after emergence (WAE), while acifluorfen, fomesafen, bentazon, thifensulfuron-methyl, cloransulam-methyl, imazethapyr, and imazethapyr plus bentazon applied POST provided 2, 2, 5, 34, 6, 4, and 12% control, respectively at 8 weeks after application (WAA). Generally, with the aforementioned herbicides, soybean yield was equivalent to the weedy control and soybean grain contamination with adzuki bean seed was consistently above the 1% maximum threshold. Chlorimuron-ethyl and glyphosate applied POST provided up to 84 and 94% visual control at 8 WAA, respectively, decreased adzuki bean density, biomass, and seed production, and generally decreased soybean contamination with adzuki bean below the 1% threshold. The only herbicides evaluated in this study that controlled volunteer adzuki bean in soybean were chlorimuron-ethyl (9 g ai.ha-1) and glyphosate (900 g ai.ha-1) applied POST. All the other PRE and POST herbicides evaluated did not provide adequate control of volunteer adzuki bean in soybean.展开更多
Eight field trials (<span style="font-family:Verdana;">2 in 2016, 3 in 2017, 3 in 2018) </span><span style="font-family:Verdana;">were conducted</span><span style="f...Eight field trials (<span style="font-family:Verdana;">2 in 2016, 3 in 2017, 3 in 2018) </span><span style="font-family:Verdana;">were conducted</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> in farmers’ fields with heavy infestations of GR </span><i><span style="font-family:Verdana;">Conyza</span></i><span style="font-family:Verdana;"> <i>canadensis</i></span><span style="font-family:Verdana;"> (Canada fleabane, horseweed or </span><span style="font-family:Verdana;">marestail</span><span style="font-family:Verdana;">) </span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">to evaluate glyphosate (900 g ae ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) plus </span><span style="font-family:Verdana;">saflufenacil</span><span style="font-family:Verdana;"> (25 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), 2,4-D ester (500 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) or paraquat (1100 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) applied </span><span style="font-family:Verdana;">preplant</span><span style="font-family:Verdana;"> (PP) as 2-way </span><span style="font-family:Verdana;">tankmixes</span><span style="font-family:Verdana;">, or in 3-way </span><span style="font-family:Verdana;">tankmixes</span><span style="font-family:Verdana;"> with sulfentrazone (140 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), flumioxazin (107 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) or metribuzin (400 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">)</span><span><span style="font-family:Verdana;"> for the glyphosate-resistant (GR) </span><i><span style="font-family:Verda展开更多
Two studies, each consisting of six field experiments were conducted in growers’ fields in 2018 and 2019 to determine the optimal herbicide tankmixes, applied preplant (PP) for the control of glyphosate-resistant<...Two studies, each consisting of six field experiments were conducted in growers’ fields in 2018 and 2019 to determine the optimal herbicide tankmixes, applied preplant (PP) for the control of glyphosate-resistant<b><span style="font-family:Verdana;"> (</span></b><span style="font-family:Verdana;">GR</span><b><span style="font-family:Verdana;">)</span></b><span style="font-family:Verdana;"> marestail in</span><span style="font-family:Verdana;"> 1) identity-preserved and glyphosate-resistant soybean (Study 1) and, 2)</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;"><span style="font-family:Verdana;">glyphosate/dicamba-resistant soybean</span></span><span style="font-family:Verdana;"> (Study 2). </span><span style="font-family:Verdana;">There was no significant injury in soybean with the PP herbicides evaluated in both studies. </span><span style="font-family:Verdana;">In Study 1, at 8 weeks after treatment (WAA), glyphosate + saflufenacil, glyphosate + 2,4-D ester, glyphosate + pyraflufen/2,4-D, glyphosate +, 4-D choline or glyphosate + halauxifen-methyl, applied PP, controlled GR marestail 93%, 58%, 60%, 67% and 71%, respectively</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> The addition of metribuzin to </span><span style="font-family:Verdana;">the tankmixes of glyphosate + </span><span style="font-family:Verdana;">saflufenacil</span><span style="font-family:Verdana;">, 2,4-D ester and pyraflufen/2,4-D increased the control to 98%, 91% and 95%, respectively. The addition of metribuzin + chlorimuron-ethyl to 2,4-D choline/glyphosate and glyphosate + halauxifen-methyl increased the control to 94% and 93%, respectively.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">In Study 2, a</span><span style="font-family:Verdana;">t </span><span style="font-family:Verdana;">8 WAA,</span><span style="font-family:Verdana;"> glyphosate/dicamba</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "展开更多
The current emphasis on reducing herbicide applications has led to an increase in alternative weed control measures. Field experiment was conducted in the spring of 2014 to examine the effect of hilling-time and reduc...The current emphasis on reducing herbicide applications has led to an increase in alternative weed control measures. Field experiment was conducted in the spring of 2014 to examine the effect of hilling-time and reduced-rates of metribuzin and their combinations on weed infestation in potato, and to determine their impact on potato yield. Metribuzin at 0.35, 0.56, or 0.75 kg ai/ha with or without hilling 6, 7, and 8 weeks after planting (WAP) were used. Weed count, weed control visual rating, weed dry weight, potato plant height, number of shoots and leaves, root dry weight, and potato yield were collected. Results showed that metribuzin, at all tested rates, with or without hilling significantly reduced weed infestation after 50, 70, and 110 days after planting (DAP) compared to the check. Best results were obtained by a combination of metribuzin at all tested rates with hilling 6, 7, and 8 WAP. The results suggest that long season weed control and high marketable yield could be achieved by metribuzin at 0.35 kg ai/ha (53% reduction in metribuzin) supplemented with hilling (6 WAP). None of the treatments was toxic to potato plants compared to the hand-weeded plots.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21971057 and U1805255)the Natural Science Foundation of Heilongjiang Province(Nos.YQ2019B006 and LH2020B012)+2 种基金the Postdoctoral Research Foundation of Heilongjiang Province(No.LBH-Q19052)the Outstanding Youth Fund of Heilongjiang University(No.JCL201901)the Basic Scientific Research Expenses of Colleges and Universities in Heilongjiang Province(No.2020-KYYWF-1008).
文摘In this work,a comparative study of three frequently employed modification techniques to g-C_(3)N_(4)(CN)nanosheets for the photocatalytic degradation of metribuzin(MET)under visible-light irradiation has been carried out in detail.The modification methods were coupling TiO_(2)nanoparticles(TO)as electron acceptors,nano-sized Fe_(2)O_(3)(FO)to construct a Z-scheme nanocomposite,and phosphate(HP)modification to promote O_(2)adsorption.The steady-state and transient-state surface photovoltage spectra and transient photoluminescence(PL)spectra confirmed that all the three modification techniques enhanced the charge separation with prolonged lifetimes and presented degradation activities in the order of TO/CN[FO/CN[HP/CN.The TO/CN nanocomposite showed the highest photocatalytic activity for MET degradation,with a sixfold higher rate than bulk CN.Liquid chromatography–tandem mass spectrometry and radical trapping experiments indicated that the increased activity was related to the synergetic effect of two radicals(·O^(2-) and ·OH)involved in the photocatalytic degradation pathway,which was different from the·OH radical-dominated pathway of bulk CN.This work reveals the importance of charge separation and the influence of the radical pathway and provides guidance for the design of high-efficiency photocatalysts.
文摘The objective of this research was to evaluate the efficacy of various pre-emergence (PRE) and post-emergence (POST) herbicides for the control of volunteer adzuki bean (Vigna angularis (Willd.) Ohwi & Ohashi) in soybean (Glycine max L.). Trials were conducted at two locations in 2005, 2006, 2007, and 2009. Experiments were arranged in a randomized complete block design with either five PRE or nine POST herbicides. Volunteer adzuki bean interference in soybean resulted in yield loss of up to 25%. Cloransulam-methyl, linuron, metribuzin, flumetsulam, and imazethapyr applied PRE provided up to 6, 24, 14, 8, and 0% control, respectively at 8 weeks after emergence (WAE), while acifluorfen, fomesafen, bentazon, thifensulfuron-methyl, cloransulam-methyl, imazethapyr, and imazethapyr plus bentazon applied POST provided 2, 2, 5, 34, 6, 4, and 12% control, respectively at 8 weeks after application (WAA). Generally, with the aforementioned herbicides, soybean yield was equivalent to the weedy control and soybean grain contamination with adzuki bean seed was consistently above the 1% maximum threshold. Chlorimuron-ethyl and glyphosate applied POST provided up to 84 and 94% visual control at 8 WAA, respectively, decreased adzuki bean density, biomass, and seed production, and generally decreased soybean contamination with adzuki bean below the 1% threshold. The only herbicides evaluated in this study that controlled volunteer adzuki bean in soybean were chlorimuron-ethyl (9 g ai.ha-1) and glyphosate (900 g ai.ha-1) applied POST. All the other PRE and POST herbicides evaluated did not provide adequate control of volunteer adzuki bean in soybean.
文摘Eight field trials (<span style="font-family:Verdana;">2 in 2016, 3 in 2017, 3 in 2018) </span><span style="font-family:Verdana;">were conducted</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> in farmers’ fields with heavy infestations of GR </span><i><span style="font-family:Verdana;">Conyza</span></i><span style="font-family:Verdana;"> <i>canadensis</i></span><span style="font-family:Verdana;"> (Canada fleabane, horseweed or </span><span style="font-family:Verdana;">marestail</span><span style="font-family:Verdana;">) </span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">to evaluate glyphosate (900 g ae ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) plus </span><span style="font-family:Verdana;">saflufenacil</span><span style="font-family:Verdana;"> (25 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), 2,4-D ester (500 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) or paraquat (1100 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) applied </span><span style="font-family:Verdana;">preplant</span><span style="font-family:Verdana;"> (PP) as 2-way </span><span style="font-family:Verdana;">tankmixes</span><span style="font-family:Verdana;">, or in 3-way </span><span style="font-family:Verdana;">tankmixes</span><span style="font-family:Verdana;"> with sulfentrazone (140 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), flumioxazin (107 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) or metribuzin (400 g ai ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">)</span><span><span style="font-family:Verdana;"> for the glyphosate-resistant (GR) </span><i><span style="font-family:Verda
文摘Two studies, each consisting of six field experiments were conducted in growers’ fields in 2018 and 2019 to determine the optimal herbicide tankmixes, applied preplant (PP) for the control of glyphosate-resistant<b><span style="font-family:Verdana;"> (</span></b><span style="font-family:Verdana;">GR</span><b><span style="font-family:Verdana;">)</span></b><span style="font-family:Verdana;"> marestail in</span><span style="font-family:Verdana;"> 1) identity-preserved and glyphosate-resistant soybean (Study 1) and, 2)</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;"><span style="font-family:Verdana;">glyphosate/dicamba-resistant soybean</span></span><span style="font-family:Verdana;"> (Study 2). </span><span style="font-family:Verdana;">There was no significant injury in soybean with the PP herbicides evaluated in both studies. </span><span style="font-family:Verdana;">In Study 1, at 8 weeks after treatment (WAA), glyphosate + saflufenacil, glyphosate + 2,4-D ester, glyphosate + pyraflufen/2,4-D, glyphosate +, 4-D choline or glyphosate + halauxifen-methyl, applied PP, controlled GR marestail 93%, 58%, 60%, 67% and 71%, respectively</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> The addition of metribuzin to </span><span style="font-family:Verdana;">the tankmixes of glyphosate + </span><span style="font-family:Verdana;">saflufenacil</span><span style="font-family:Verdana;">, 2,4-D ester and pyraflufen/2,4-D increased the control to 98%, 91% and 95%, respectively. The addition of metribuzin + chlorimuron-ethyl to 2,4-D choline/glyphosate and glyphosate + halauxifen-methyl increased the control to 94% and 93%, respectively.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">In Study 2, a</span><span style="font-family:Verdana;">t </span><span style="font-family:Verdana;">8 WAA,</span><span style="font-family:Verdana;"> glyphosate/dicamba</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "
文摘The current emphasis on reducing herbicide applications has led to an increase in alternative weed control measures. Field experiment was conducted in the spring of 2014 to examine the effect of hilling-time and reduced-rates of metribuzin and their combinations on weed infestation in potato, and to determine their impact on potato yield. Metribuzin at 0.35, 0.56, or 0.75 kg ai/ha with or without hilling 6, 7, and 8 weeks after planting (WAP) were used. Weed count, weed control visual rating, weed dry weight, potato plant height, number of shoots and leaves, root dry weight, and potato yield were collected. Results showed that metribuzin, at all tested rates, with or without hilling significantly reduced weed infestation after 50, 70, and 110 days after planting (DAP) compared to the check. Best results were obtained by a combination of metribuzin at all tested rates with hilling 6, 7, and 8 WAP. The results suggest that long season weed control and high marketable yield could be achieved by metribuzin at 0.35 kg ai/ha (53% reduction in metribuzin) supplemented with hilling (6 WAP). None of the treatments was toxic to potato plants compared to the hand-weeded plots.
