Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100006
M. Akbar, I. Sherazi, M. S. Iqbal, T. Khalil, H. Waqas
ABSTRACT: In the present study, antibacterial and antioxidant [1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity] activities of a weed, slender amaranth (Amaranthus viridis L.) were investigated. Extracts of different plant parts were prepared in n-hexane, chloroform and ethyl acetate. Antibacterial activity was measured by using 100 mg mL-1 concentration extracts against 4 deadly phytopathogenic bacterial species viz. Pseudomonas syringae Van Hall, Ralstonia solanacearum Smith, Erwinia carotovora (Jones), Holland and Xanthomonas axonopodis Hasse. In antioxidants assays, 10, 20 and 30 mg mL-1 extracts were used keeping DPPH as control. In these bioassays, ethyl acetate fraction of A. viridis leaf exhibited the best antibacterial and antioxidants activity. Ethyl acetate leaf fraction showed the highest inhibition zone diameter (IZD) where it caused 21 mm IZD against P. syringae and 19 mm IZD against E. carotovora. This extract also showed 22, 52 and 84% antioxidant activity at 10, 20 and 30 mg mL-1 concentrations, respectively. Previously there is no report available that describes antibacterial activity of root extract of A. viridis against P. syringae. Moreover, antioxidant activity of stem and root extracts in n-hexane, chloroform and ethyl acetate was investigated first time in the world. It was concluded that the biological activities observed during the present investigation may be due to the presence of bioactive constituents that can be harnessed as natural antibacterials and antioxidants.
{"title":"Antibacterial and Antioxidant Activities of Slender Amaranth Weed","authors":"M. Akbar, I. Sherazi, M. S. Iqbal, T. Khalil, H. Waqas","doi":"10.1590/s0100-83582020380100006","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100006","url":null,"abstract":"ABSTRACT: In the present study, antibacterial and antioxidant [1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity] activities of a weed, slender amaranth (Amaranthus viridis L.) were investigated. Extracts of different plant parts were prepared in n-hexane, chloroform and ethyl acetate. Antibacterial activity was measured by using 100 mg mL-1 concentration extracts against 4 deadly phytopathogenic bacterial species viz. Pseudomonas syringae Van Hall, Ralstonia solanacearum Smith, Erwinia carotovora (Jones), Holland and Xanthomonas axonopodis Hasse. In antioxidants assays, 10, 20 and 30 mg mL-1 extracts were used keeping DPPH as control. In these bioassays, ethyl acetate fraction of A. viridis leaf exhibited the best antibacterial and antioxidants activity. Ethyl acetate leaf fraction showed the highest inhibition zone diameter (IZD) where it caused 21 mm IZD against P. syringae and 19 mm IZD against E. carotovora. This extract also showed 22, 52 and 84% antioxidant activity at 10, 20 and 30 mg mL-1 concentrations, respectively. Previously there is no report available that describes antibacterial activity of root extract of A. viridis against P. syringae. Moreover, antioxidant activity of stem and root extracts in n-hexane, chloroform and ethyl acetate was investigated first time in the world. It was concluded that the biological activities observed during the present investigation may be due to the presence of bioactive constituents that can be harnessed as natural antibacterials and antioxidants.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67277909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100008
R. Akhtar, A. Javaid, M. Qureshi
ABSTRACT: The present study was carried out to check the antifungal potential of Sisymbrium irio L. shoot extract against Fusarium oxysporum f. sp. cepae (FOC). In preliminary bioassays, different concentrations (1 to 5%) of leaf, stem and fruit extracts were evaluated against FOC. All the extracts were effective against the pathogen. However, the leaf extract was found the most effective causing 25-41% decrease in FOC biomass. The fractionation of methanolic leaf extract was done by two organic solvents namely n-hexane and chloroform. Different concentrations (1.56 to 200 mg mL-1) of these fractions were tested against FOC. The n-hexane and chloroform fractions showed inhibitory activity against the pathogen and resulted in 77-93% and 80-96% reduction in biomass of FOC, respectively. GC-MS analysis showed the presence of 24 compounds in n-hexane and 4 compounds in chloroform fraction. In n-hexane fraction, β-sitosterol (18.64%) was the most abundant compound followed by orotic acid, bis(tert-butyldimethylsilyl)-, tert-butyldimethylsilyl ester (12.18%), 10-octadecenoic acid, methyl ester (7.90%) and 1,2-benzenedicarboxylic acid, diisooctyl ester (6.05%). Major compounds identified in chloroform fraction were 1,3-benzenedicarboxylic acid, bis(2-ethylhexyl) ester (50.82%) and di-n-octyl phthalate (33.00%). This study concludes that n-hexane and chloroform fractions of methanolic leaf extract of S. irio contain potent antifungal constituents for the management of FOC.
{"title":"Bioactive Constituents of Shoot Extracts of Sisymbrium irio L. Against Fusarium oxysporum f. sp. cepae","authors":"R. Akhtar, A. Javaid, M. Qureshi","doi":"10.1590/s0100-83582020380100008","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100008","url":null,"abstract":"ABSTRACT: The present study was carried out to check the antifungal potential of Sisymbrium irio L. shoot extract against Fusarium oxysporum f. sp. cepae (FOC). In preliminary bioassays, different concentrations (1 to 5%) of leaf, stem and fruit extracts were evaluated against FOC. All the extracts were effective against the pathogen. However, the leaf extract was found the most effective causing 25-41% decrease in FOC biomass. The fractionation of methanolic leaf extract was done by two organic solvents namely n-hexane and chloroform. Different concentrations (1.56 to 200 mg mL-1) of these fractions were tested against FOC. The n-hexane and chloroform fractions showed inhibitory activity against the pathogen and resulted in 77-93% and 80-96% reduction in biomass of FOC, respectively. GC-MS analysis showed the presence of 24 compounds in n-hexane and 4 compounds in chloroform fraction. In n-hexane fraction, β-sitosterol (18.64%) was the most abundant compound followed by orotic acid, bis(tert-butyldimethylsilyl)-, tert-butyldimethylsilyl ester (12.18%), 10-octadecenoic acid, methyl ester (7.90%) and 1,2-benzenedicarboxylic acid, diisooctyl ester (6.05%). Major compounds identified in chloroform fraction were 1,3-benzenedicarboxylic acid, bis(2-ethylhexyl) ester (50.82%) and di-n-octyl phthalate (33.00%). This study concludes that n-hexane and chloroform fractions of methanolic leaf extract of S. irio contain potent antifungal constituents for the management of FOC.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67277976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100069
A. Aliverdi, G. Ahmadvand, Behzad Emami-Namivandi
Background: The application of appropriately timed herbicide is an affordable approach to optimize the activity of herbicides. Objective: The study aims to determine the best night-time to apply glufosinate, oxyfluorfen, and paraquat with emphasis on the role of the period of dark exposure after herbicide application. Methods: The study was conducted at two fields in Iran, the fresh weight: dry weight (FW/DW) ratio of five weed species treated with glufosinate, oxyfluorfen, and paraquat at 0.5x and 1x of labeled doses after sunset or before sunrise was assessed. Results: The application time-of-day effect for tested herbicides was affected by application dose of herbicide and was more pronounced when the herbicides were applied at the 0.5x as compared to at the 1x. In 14 out of 18 cases, foliage tissues were more desiccated with the sunset applications of herbicides at the 0.5x than with the sunrise applications. When applications were made after sunset, an increased foliage tissues desiccation of Chenopodium album L. treated with paraquat (29.6%) in field 1 and C. album treated with glufosinate (27.2%) or paraquat (23.7%), and Malva neglecta Wallr. treated with glufosinate (21.6%) or oxyfluorfen (31.6%) in field 2 was detected by increasing the dose from 0.5x to 1x. Except 4 out of 18 cases, the herbicides applied either at the 0.5x after sunset or at the 1x before sunrise resulted in similar FW/DW ratio in all weed species. Conclusions: If contact herbicides are used at night-time after sunset, it is possible to take advantage of their reduced doses.
背景:适时施用除草剂是优化除草剂活性的有效途径。目的:确定草铵膦、氧氟醚和百草枯的最佳夜间施药时间,重点研究除草剂施药后黑暗暴露时间的影响。方法:在伊朗的两个田间,分别以标记剂量的0.5倍和1倍的剂量,对日落后或日出前用草酰膦、氧氟醚和百草枯处理5种杂草的鲜重:干重(FW/DW)比进行测定。结果:被试除草剂的施药时间效应受除草剂施药剂量的影响,在0.5倍施药时比在1x施药时更为明显。在18个案例中,有14个案例在0.5倍的剂量下,日落施药比日出施药的叶片组织更干燥。在日落后施药时,在田间1施用百草枯(29.6%)和草铵膦(27.2%)或百草枯(23.7%)处理的藜麦(Chenopodium album L.)叶片组织干燥度增加,而在田间1施用百草枯(23.7%)处理的藜麦(Malva忽略Wallr)叶片组织干燥度增加。在田间2用草甘膦(21.6%)或氟氧芬(31.6%)处理,剂量由0.5倍增加到1倍。除4例外,在日落后0.5倍和日出前1x施用除草剂对所有杂草的FW/DW比基本一致。结论:如果在日落之后的夜间使用接触除草剂,可以利用其减少的剂量。
{"title":"Weed control of glufosinate, oxyfluorfen, and paraquat as affected by the application time of day","authors":"A. Aliverdi, G. Ahmadvand, Behzad Emami-Namivandi","doi":"10.1590/s0100-83582020380100069","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100069","url":null,"abstract":"Background: The application of appropriately timed herbicide is an affordable approach to optimize the activity of herbicides. Objective: The study aims to determine the best night-time to apply glufosinate, oxyfluorfen, and paraquat with emphasis on the role of the period of dark exposure after herbicide application. Methods: The study was conducted at two fields in Iran, the fresh weight: dry weight (FW/DW) ratio of five weed species treated with glufosinate, oxyfluorfen, and paraquat at 0.5x and 1x of labeled doses after sunset or before sunrise was assessed. Results: The application time-of-day effect for tested herbicides was affected by application dose of herbicide and was more pronounced when the herbicides were applied at the 0.5x as compared to at the 1x. In 14 out of 18 cases, foliage tissues were more desiccated with the sunset applications of herbicides at the 0.5x than with the sunrise applications. When applications were made after sunset, an increased foliage tissues desiccation of Chenopodium album L. treated with paraquat (29.6%) in field 1 and C. album treated with glufosinate (27.2%) or paraquat (23.7%), and Malva neglecta Wallr. treated with glufosinate (21.6%) or oxyfluorfen (31.6%) in field 2 was detected by increasing the dose from 0.5x to 1x. Except 4 out of 18 cases, the herbicides applied either at the 0.5x after sunset or at the 1x before sunrise resulted in similar FW/DW ratio in all weed species. Conclusions: If contact herbicides are used at night-time after sunset, it is possible to take advantage of their reduced doses.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67279188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100080
A. Hussain, Abdul A. Khakwani, A. Tanveer, Ejaz A. Khan, Mohammad S. Baloch
Background: Conyza stricta L. (Horse weed) is an annual problematic weed in an agricultural ecosystem and considerably decreases the crop yield and quality. Objective: To determine the most effective pre and post emergence herbicides and their dose to control C. stricta in sugarcane crop. Methods: A two years field study comprised of six herbicides treatments along with weedy check and hand weeding. The design of study was RCBD with three replications. Results: Hand weeding recorded more leaf area index (LAI), crop growth rate (CGR) and net assimilation rate (NAR), biological and stripped yield. However, greater LAI, CGR and NAR, biological and stripped yield were recorded by acetochlor + atrazine at the rate of 2,715 g ha-1 (pre emergence) and dicamba at the rate of 466 g ha-1 (post emergence). All the treatments produced statistically comparable harvest index except weedy check, which produced less harvest index. Minimum C. stricta density and dry weight were recorded for acetochlor + atrazine at the rate of 2,715 g ha-1 and dicamba at the rate of 466 g ha-1. Acetochlor + atrazine at the rate of 2,715 g ha-1 (pre emergence) and dicamba at the rate of 466 g ha-1 (post emergence) gave better C. stricta control with high herbicides efficiency index. Conclusion: Acetochlor + atrazine at the rate of 2,715 g ha-1 (pre emergence) or dicamba at the rate of 466 g ha-1 (post emergence) may be used for efficient control of C. stricta in sugarcane.
背景:马鞭草是农业生态系统中的一种年度问题杂草,严重影响作物产量和质量。目的:确定出苗前、出苗后除草剂防治蔗螟的最有效剂量。方法:采用为期两年的野外试验,采用六种除草剂处理,并进行杂草检查和手工除草。研究设计为RCBD, 3个重复。结果:手工除草获得了更高的叶面积指数(LAI)、作物生长率(CGR)、净同化率(NAR)、生物产量和剥落产量。然而,乙草胺+阿特拉嗪(羽化前)和麦草枯(羽化后)分别以2715 g ha-1和466 g ha-1的产量记录了更高的LAI、CGR和NAR,生物产量和剥脱产量。除杂草处理的收获指数较低外,其余处理的收获指数均具有统计学上的可比性。乙草胺+阿特拉津用量为2715 g ha-1时,麦草畏用量为466 g ha-1时,记录了最小密度和干重。乙草胺+阿特拉津(羽化前)用量为2715 g ha-1,麦草畏(羽化后)用量为466 g ha-1,防治效果较好,且药效指数较高。结论:用乙草胺+阿特拉嗪(羽化前2,715 g ha-1)或麦草枯(羽化后466 g ha-1)可有效防治蔗螟。
{"title":"Optimizing efficacy of acetochlor + atrazine and dicamba at various doses to manage Conyza stricta L. in sugarcane","authors":"A. Hussain, Abdul A. Khakwani, A. Tanveer, Ejaz A. Khan, Mohammad S. Baloch","doi":"10.1590/s0100-83582020380100080","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100080","url":null,"abstract":"Background: Conyza stricta L. (Horse weed) is an annual problematic weed in an agricultural ecosystem and considerably decreases the crop yield and quality. Objective: To determine the most effective pre and post emergence herbicides and their dose to control C. stricta in sugarcane crop. Methods: A two years field study comprised of six herbicides treatments along with weedy check and hand weeding. The design of study was RCBD with three replications. Results: Hand weeding recorded more leaf area index (LAI), crop growth rate (CGR) and net assimilation rate (NAR), biological and stripped yield. However, greater LAI, CGR and NAR, biological and stripped yield were recorded by acetochlor + atrazine at the rate of 2,715 g ha-1 (pre emergence) and dicamba at the rate of 466 g ha-1 (post emergence). All the treatments produced statistically comparable harvest index except weedy check, which produced less harvest index. Minimum C. stricta density and dry weight were recorded for acetochlor + atrazine at the rate of 2,715 g ha-1 and dicamba at the rate of 466 g ha-1. Acetochlor + atrazine at the rate of 2,715 g ha-1 (pre emergence) and dicamba at the rate of 466 g ha-1 (post emergence) gave better C. stricta control with high herbicides efficiency index. Conclusion: Acetochlor + atrazine at the rate of 2,715 g ha-1 (pre emergence) or dicamba at the rate of 466 g ha-1 (post emergence) may be used for efficient control of C. stricta in sugarcane.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"26 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67279549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100061
Laís T. Perboni, D. Agostinetto, Juliano Gazola, Daniela Tessaro, Marlon M. Teixeira, Alessandro Neutzling
Background: Plants synthesize compounds of specialized metabolism to defend themselves against biotic and abiotic stresses. These compounds could be used as models for pesticide development. Among the species that have not yet been studied for the potential to produce active compounds is the kidney leaf mud plantain (Heteranthera reniformis). Objective: The goal was to evaluate the effect of hexanic, ethyl acetate and methanolic extracts of H. reniformis leaves on cress (Lepidium sativum) seed germination to determine which one have the highest biological activity; and to evaluate different concentrations of extract with the highest biological activity on lettuce (Lactuca sativa), barnyard grass (Echinochloa sp.) and giant arrowhead (Sagittaria montevidensis) germination. Methods: The seeds were placed on petri dishes containing two sheets of germitest paper, and after the application of the extract, they were sealed and placed in growth chambers with controlled temperature and photoperiod. The variables analyzed were 1st and 2nd germination count, germination speed index and length of the aerial part and roots. Results: The ethyl acetate extract provided greater phytotoxicity on cress than the other extracts. In general, the highest concentration of ethyl acetate extract was the most efficient in reducing variables for all species. Conclusions: The ethyl acetate extract of H. reniformis presents inhibitory activity on the seeds of cress, lettuce, giant arrowhead and barnyard grass, but this activity was dependent on the concentration of the extract and the species studied. H. reniformis synthesizes compounds with phytotoxic activity and purification of extracts is required to isolate, identify and characterize the action mechanism of the compounds with herbicide activity, so that in the future these can be used as models for the development of herbicides. SBCPD | Planta Daninha Perboni LT, et al. Herbicidal activity of kidney leaf mud plantain extracts Planta Daninha 2020;38:e020229957 https://doi.org/10.1590/S0100-83582020380100061 2/10
{"title":"Herbicidal activity of kidney leaf mud plantain leaves extracts on the germination of four species","authors":"Laís T. Perboni, D. Agostinetto, Juliano Gazola, Daniela Tessaro, Marlon M. Teixeira, Alessandro Neutzling","doi":"10.1590/s0100-83582020380100061","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100061","url":null,"abstract":"Background: Plants synthesize compounds of specialized metabolism to defend themselves against biotic and abiotic stresses. These compounds could be used as models for pesticide development. Among the species that have not yet been studied for the potential to produce active compounds is the kidney leaf mud plantain (Heteranthera reniformis). Objective: The goal was to evaluate the effect of hexanic, ethyl acetate and methanolic extracts of H. reniformis leaves on cress (Lepidium sativum) seed germination to determine which one have the highest biological activity; and to evaluate different concentrations of extract with the highest biological activity on lettuce (Lactuca sativa), barnyard grass (Echinochloa sp.) and giant arrowhead (Sagittaria montevidensis) germination. Methods: The seeds were placed on petri dishes containing two sheets of germitest paper, and after the application of the extract, they were sealed and placed in growth chambers with controlled temperature and photoperiod. The variables analyzed were 1st and 2nd germination count, germination speed index and length of the aerial part and roots. Results: The ethyl acetate extract provided greater phytotoxicity on cress than the other extracts. In general, the highest concentration of ethyl acetate extract was the most efficient in reducing variables for all species. Conclusions: The ethyl acetate extract of H. reniformis presents inhibitory activity on the seeds of cress, lettuce, giant arrowhead and barnyard grass, but this activity was dependent on the concentration of the extract and the species studied. H. reniformis synthesizes compounds with phytotoxic activity and purification of extracts is required to isolate, identify and characterize the action mechanism of the compounds with herbicide activity, so that in the future these can be used as models for the development of herbicides. SBCPD | Planta Daninha Perboni LT, et al. Herbicidal activity of kidney leaf mud plantain extracts Planta Daninha 2020;38:e020229957 https://doi.org/10.1590/S0100-83582020380100061 2/10","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100063
M. Akbar, Iram N. Sherazi, T. Khalil, Muhammad S. Iqbal, S. Akhtar, Salik N. Khan
Background: Antifungal activity of slender amaranth (Amaranthus viridis L.) is well documented but such studies are scarce in Pakistan, especially against plant pathogens. It was hypothesized that A. viridis has antifungal activity against fungal phyto-pathogens also. Objective: Identification of antifungal constituents from leaf extracts of A. viridis. Methods: Different organic solvent extracts of A. viridis leaves were evaluated against 5 plant pathogenic fungal species viz. Alternaria alternata, Aspergillus flavus, Drechslera australiensis, Fusarium oxysporum and Macrophomina phaseolina. Antifungal activity of A. viridis was determined by serial dilution method. Six levels (0, 5, 10, 15, 20 and 25 mg mL-1) of treatments of each n-hexane, chloroform and ethyl acetate were employed against all fungal species in a Completely Randomised Design (CRD). Results: Generally, all organic solvent extracts reduced the fungal biomass significantly with the increase in extract concentration but ethyl acetate leaf fraction exhibited pronounced activity and reduced the fungal growth up to 44% in A. alternata, 39% in A. flavus, 48% in D. australiensis, 48% in F. oxysporum and 45% in M. phaseolina. Gas Chromatography Mass Spectrometry (GCMS) analysis of ethyl acetate leaf fraction revealed 09 compounds. Out of these 9 compounds, one compound identified as 1,2Benzenedicarboxylic acid, mono (2-ethylhexyl) ester) showed 58.5% peak value. Conclusions: It was concluded that 1,2Benzenedicarboxylic acid, mono (2-ethylhexyl) ester) being in the highest concentration in the ethyl acetate leaf fraction of A. viridis may be responsible for antifungal activity. This compound can serve as structural analog to develop ecofriendly fungicides.
{"title":"Identification of antifungal compounds from slender amaranth","authors":"M. Akbar, Iram N. Sherazi, T. Khalil, Muhammad S. Iqbal, S. Akhtar, Salik N. Khan","doi":"10.1590/s0100-83582020380100063","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100063","url":null,"abstract":"Background: Antifungal activity of slender amaranth (Amaranthus viridis L.) is well documented but such studies are scarce in Pakistan, especially against plant pathogens. It was hypothesized that A. viridis has antifungal activity against fungal phyto-pathogens also. Objective: Identification of antifungal constituents from leaf extracts of A. viridis. Methods: Different organic solvent extracts of A. viridis leaves were evaluated against 5 plant pathogenic fungal species viz. Alternaria alternata, Aspergillus flavus, Drechslera australiensis, Fusarium oxysporum and Macrophomina phaseolina. Antifungal activity of A. viridis was determined by serial dilution method. Six levels (0, 5, 10, 15, 20 and 25 mg mL-1) of treatments of each n-hexane, chloroform and ethyl acetate were employed against all fungal species in a Completely Randomised Design (CRD). Results: Generally, all organic solvent extracts reduced the fungal biomass significantly with the increase in extract concentration but ethyl acetate leaf fraction exhibited pronounced activity and reduced the fungal growth up to 44% in A. alternata, 39% in A. flavus, 48% in D. australiensis, 48% in F. oxysporum and 45% in M. phaseolina. Gas Chromatography Mass Spectrometry (GCMS) analysis of ethyl acetate leaf fraction revealed 09 compounds. Out of these 9 compounds, one compound identified as 1,2Benzenedicarboxylic acid, mono (2-ethylhexyl) ester) showed 58.5% peak value. Conclusions: It was concluded that 1,2Benzenedicarboxylic acid, mono (2-ethylhexyl) ester) being in the highest concentration in the ethyl acetate leaf fraction of A. viridis may be responsible for antifungal activity. This compound can serve as structural analog to develop ecofriendly fungicides.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67279014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100033
R. T. Raimondi, J. Constantin, R. Mendes, R. S. Oliveira Jr, F. A. Rios
ABSTRACT: Currently, sourgrass is one of the most important weeds in grain production areas in Brazil. The objective of this work was to evaluate the efficiency of associated systems composed by mowing and chemical control against clumped sourgrass. In the first experiment, different mowing heights (0, 5, 10, 15 and 20 cm), coupled with complementary applications of glyphosate + clethodim, were evaluated on sourgrass control. The second experiment was composed by programs starting with fallow mowing at different times, 50 (early), 35 (intermediate) and 20 (late) days before soybean sowing. After mowing, treatments were followed by herbicide applications according to the need until soybean harvest. The shorter the mowing height associated with herbicide application, the better the control of sourgrass. The weed management programs (anticipated, intermediate and late) were efficient on sourgrass control during fallow and along soybean cycle. Weed management programs starting with mowing provided better or similar control compared to systems that employed chemical control only, indicating that mowing can replace one of the herbicide applications.
{"title":"Glyphosate-Resistant Sourgrass Management Programs Associating Mowing and Herbicides","authors":"R. T. Raimondi, J. Constantin, R. Mendes, R. S. Oliveira Jr, F. A. Rios","doi":"10.1590/s0100-83582020380100033","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100033","url":null,"abstract":"ABSTRACT: Currently, sourgrass is one of the most important weeds in grain production areas in Brazil. The objective of this work was to evaluate the efficiency of associated systems composed by mowing and chemical control against clumped sourgrass. In the first experiment, different mowing heights (0, 5, 10, 15 and 20 cm), coupled with complementary applications of glyphosate + clethodim, were evaluated on sourgrass control. The second experiment was composed by programs starting with fallow mowing at different times, 50 (early), 35 (intermediate) and 20 (late) days before soybean sowing. After mowing, treatments were followed by herbicide applications according to the need until soybean harvest. The shorter the mowing height associated with herbicide application, the better the control of sourgrass. The weed management programs (anticipated, intermediate and late) were efficient on sourgrass control during fallow and along soybean cycle. Weed management programs starting with mowing provided better or similar control compared to systems that employed chemical control only, indicating that mowing can replace one of the herbicide applications.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100037
L. Sangoi, M. M. Durli, C. A. Souza, L. Leolato, H. F. Kuneski, A. Coelho
ABSTRACT: High nitrogen rates favor maize vegetative growth and grain yield losses due to stem lodging. The use of growth regulators can mitigate such effect. This work was carried out aiming to evaluate the effect of trinexapac ethyl on maize hybrids response to side-dress nitrogen rates. The experiment was carried out in Lages, Santa Catarina State, South of Brazil, during two growing seasons with two hybrids (P1680 and P30F53), and four nitrogen rates (0, 150, 300 and 450 kg N ha-1) were tested, with and without the presence of trinexapac ethyl. The experimental design was in randomized blocks arranged in split-split plots, with three replications per treatment. The plants height and ear insertion height, plant lodging and breaking, grain yield and yield components were evaluated. Grain yield increased in a quadratic way with increased nitrogen rate. The highest grain yields were 15,784 and 15,257 kg ha-1, in 2014/15 and 2015/16, respectively. Application rates higher than 150 kg of N ha-1, regardless of the use of the plant growth regulator, promoted maximum grain yield increases, ranging from 14.7 to 18.1%. The application of trinexapac-ethyl reduced the upper stem internode length, 1000-grain dry weight and did not affect the percentage of lodged plants and grain yield of both hybrids. Therefore, the use of trinexapac-ethyl did not enhance the maize grain yield response to increased rates of side-dress nitrogen.
摘要/ ABSTRACT摘要:高施氮量有利于玉米的营养生长和茎秆倒伏造成的产量损失。使用生长调节剂可以减轻这种影响。本试验旨在评价trinexapac乙酯对玉米杂交种侧施氮量的影响。试验在巴西南部圣卡塔琳娜州的Lages进行,在两个生长季节用两个杂交种(P1680和P30F53),在使用和不使用trinexapac ethyl的情况下,测试了四种氮肥水平(0、150、300和450 kg N ha-1)。试验设计采用随机分组,按分割区排列,每个处理重复3次。评价了株高和穗高、倒伏和断穗、籽粒产量和产量构成因素。籽粒产量随施氮量的增加呈二次曲线增长。2014/15和2015/16籽粒最高产量分别为15784和15257公斤/公顷。施氮量大于150 kg hm -1时,无论施用何种植物生长调节剂,籽粒产量增幅最大,为14.7% ~ 18.1%。施用trinexapac-乙酯后,两个杂交种的茎上节间长和千粒干重均有所减少,但对结块率和产量没有影响。因此,施用trinexapac-乙基并没有提高玉米产量对侧施氮量的响应。
{"title":"Maize Response to Trinexapac-Ethyl and Nitrogen Fertilization","authors":"L. Sangoi, M. M. Durli, C. A. Souza, L. Leolato, H. F. Kuneski, A. Coelho","doi":"10.1590/s0100-83582020380100037","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100037","url":null,"abstract":"ABSTRACT: High nitrogen rates favor maize vegetative growth and grain yield losses due to stem lodging. The use of growth regulators can mitigate such effect. This work was carried out aiming to evaluate the effect of trinexapac ethyl on maize hybrids response to side-dress nitrogen rates. The experiment was carried out in Lages, Santa Catarina State, South of Brazil, during two growing seasons with two hybrids (P1680 and P30F53), and four nitrogen rates (0, 150, 300 and 450 kg N ha-1) were tested, with and without the presence of trinexapac ethyl. The experimental design was in randomized blocks arranged in split-split plots, with three replications per treatment. The plants height and ear insertion height, plant lodging and breaking, grain yield and yield components were evaluated. Grain yield increased in a quadratic way with increased nitrogen rate. The highest grain yields were 15,784 and 15,257 kg ha-1, in 2014/15 and 2015/16, respectively. Application rates higher than 150 kg of N ha-1, regardless of the use of the plant growth regulator, promoted maximum grain yield increases, ranging from 14.7 to 18.1%. The application of trinexapac-ethyl reduced the upper stem internode length, 1000-grain dry weight and did not affect the percentage of lodged plants and grain yield of both hybrids. Therefore, the use of trinexapac-ethyl did not enhance the maize grain yield response to increased rates of side-dress nitrogen.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100067
Muhammad N. Mushtaq, Muhammad I. Hashmi, Tabinda Tariq, Amar Matloob, S. Hussain, Zahid A. Cheema
Background: Continuous use of commercial herbicides is posing a severe threat to environment and creating herbicide resistant weeds. Allelopathy offers a promising alternative to commercial herbicides for sustainable weed management. The farmers are highly concerned with maximum yield as well as cost of the weed control techniques. Objective: To investigate economic and weed control efficiency of allelopathic crop water leachates mixed with lower rates of herbicide. Methods: Rapeseed (Brassica napus L.), sunflower (Helianthus annuus L.) and sorghum (Sorghum bicolor L.) crop leachates (18 L ha-1 each) tank mixed with lower doses (25, 33 and 50% of recommended dose) of S-metolachlor+atrazine were sprayed as pre-emergence for horse purslane (Trianthema portulacastrum L.) management in maize (Zea mays L.). Label dose (1,080 g a.i. ha-1) of herbicide (S-metolachlor+atrazine) and a weedy check treatment were also maintained. Results: The results showed that rapeseed+sunflower+sorghum allelopathic leachates mixed with half dose (540 g a.i. ha-1) of S-metolachlor+atrazine was effective against horse purslane and increased maize yield (grain) by 45% and 5% as compared with control and label dose of herbicide, respectively. Likewise, economic analysis showed that the same treatment was most economical with 40% and 9% higher net benefits than control and label dose of herbicide, respectively and 2407% marginal rate of return. It also gave an additional benefit of US$ 24.07 for investment of every US$1. Conclusions: By using this technique, herbicides use can be minimized by 50% for sustainable weed management without compromising maize yield and net benefits. SBCPD | Planta Daninha Mushtaq MN, et al. Allelopathy to manage horse purslane Planta Daninha 2020;38:e020214748 https://doi.org/10.1590/S0100-83582020380100067 2/7
背景:持续使用商业除草剂对环境造成严重威胁,并产生抗除草剂杂草。化感作用为可持续杂草管理提供了一种有前途的替代商业除草剂。农民们高度关注最大产量以及杂草控制技术的成本。目的:考察化感作物渗滤液与低用量除草剂混用的经济性和除草效果。方法:采用油菜(Brassica napus L.)、向日葵(Helianthus annuus L.)和高粱(sorghum bicolor L.)作物渗滤液(各18 L ha-1)池,混合低剂量(25,33和50%推荐剂量)的s -异丙甲草胺+阿特拉津,作为马马苋(Trianthema portulacastrum L.)在玉米(Zea mays L.)管理中的预喷处理。除草剂(s -甲草胺+阿特拉津)的标签剂量(1080 g a.i. ha-1)和杂草检查处理也保持不变。结果:油菜籽+向日葵+高粱化感浸出液与半剂量(540 g a.i. ha-1) s -甲草胺+阿特拉津混合对马齿苋有效,玉米产量(粒)比对照和标记剂量分别提高45%和5%。同样,经济分析表明,相同处理最经济,净效益分别比对照和标记剂量除草剂高40%和9%,边际收益率为2407%。每投资1美元,可获得24.07美元的额外收益。结论:通过使用该技术,在不影响玉米产量和净效益的情况下,可将除草剂使用量减少50%,实现可持续杂草管理。[b] [b] plant Daninha Mushtaq MN,等。马齿苋化感作用的研究进展,植物学报,2020;38:e020214748 https://doi.org/10.1590/S0100-83582020380100067 2/7
{"title":"Bioeconomic evaluation of allelopathic crop leachates integrated with reduced doses of herbicide for horse purslane management in maize under field conditions","authors":"Muhammad N. Mushtaq, Muhammad I. Hashmi, Tabinda Tariq, Amar Matloob, S. Hussain, Zahid A. Cheema","doi":"10.1590/s0100-83582020380100067","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100067","url":null,"abstract":"Background: Continuous use of commercial herbicides is posing a severe threat to environment and creating herbicide resistant weeds. Allelopathy offers a promising alternative to commercial herbicides for sustainable weed management. The farmers are highly concerned with maximum yield as well as cost of the weed control techniques. Objective: To investigate economic and weed control efficiency of allelopathic crop water leachates mixed with lower rates of herbicide. Methods: Rapeseed (Brassica napus L.), sunflower (Helianthus annuus L.) and sorghum (Sorghum bicolor L.) crop leachates (18 L ha-1 each) tank mixed with lower doses (25, 33 and 50% of recommended dose) of S-metolachlor+atrazine were sprayed as pre-emergence for horse purslane (Trianthema portulacastrum L.) management in maize (Zea mays L.). Label dose (1,080 g a.i. ha-1) of herbicide (S-metolachlor+atrazine) and a weedy check treatment were also maintained. Results: The results showed that rapeseed+sunflower+sorghum allelopathic leachates mixed with half dose (540 g a.i. ha-1) of S-metolachlor+atrazine was effective against horse purslane and increased maize yield (grain) by 45% and 5% as compared with control and label dose of herbicide, respectively. Likewise, economic analysis showed that the same treatment was most economical with 40% and 9% higher net benefits than control and label dose of herbicide, respectively and 2407% marginal rate of return. It also gave an additional benefit of US$ 24.07 for investment of every US$1. Conclusions: By using this technique, herbicides use can be minimized by 50% for sustainable weed management without compromising maize yield and net benefits. SBCPD | Planta Daninha Mushtaq MN, et al. Allelopathy to manage horse purslane Planta Daninha 2020;38:e020214748 https://doi.org/10.1590/S0100-83582020380100067 2/7","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67279583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100001
J. Iqbal, M. Rehmani, S. Sagheer, N. Kaleem, J. Muneer
ABSTRACT: Dry land plants owing to their capability to grow under stressful environment have shown higher allelopathic potential as compared to cultivated plants. An experiment was conducted to investigate the herbicidal potential of aqueous extracts of four dry land plants viz. fruit and vine of Citrullus colocynthis, and above ground parts of Rhazya stricta; Crotalaria burhia and Calligonum polygonoides, with four concentrations (25, 50, 75 and 100%) of initially prepared extracts against Lathyrus aphaca, a common weed of wheat in the studied region. These plants were collected from dry land area (30.03° N and 70.38° E, 129 m above sea level, almost desert conditions) of Dera Ghazi Khan, Punjab, Pakistan. All the four plants exhibited pronounced herbicidal potential with 9 to 91% suppression of different parameters in L. aphaca). Maximum inhibition was recorded in germination (36-91%). Significant suppression in leaf count (9-65%), shoot length (12-59%), root length (4-62%), shoot fresh weight (17-71%), root fresh weight (10-60%), shoot dry weight (15-72%), root dry weight (13-64%), and nodule numbers (34-89%) was also observed. The highest inhibition was exhibited by R. stricta followed by C. colocynthis: fruit. However, in case of nodulation maximum suppression was produced by C. burhia extract. Least suppressant activity was observed for the C. polygonides extract. These results encourage the potential use of locally available dry land plants possessing strong allelochemical properties for nonchemical control of weeds ultimately reducing reliance on chemical control.
{"title":"Herbicidal Potential of Some Dry Land Plants Against Lathyrus aphaca (L.), Winter Season Weed","authors":"J. Iqbal, M. Rehmani, S. Sagheer, N. Kaleem, J. Muneer","doi":"10.1590/s0100-83582020380100001","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100001","url":null,"abstract":"ABSTRACT: Dry land plants owing to their capability to grow under stressful environment have shown higher allelopathic potential as compared to cultivated plants. An experiment was conducted to investigate the herbicidal potential of aqueous extracts of four dry land plants viz. fruit and vine of Citrullus colocynthis, and above ground parts of Rhazya stricta; Crotalaria burhia and Calligonum polygonoides, with four concentrations (25, 50, 75 and 100%) of initially prepared extracts against Lathyrus aphaca, a common weed of wheat in the studied region. These plants were collected from dry land area (30.03° N and 70.38° E, 129 m above sea level, almost desert conditions) of Dera Ghazi Khan, Punjab, Pakistan. All the four plants exhibited pronounced herbicidal potential with 9 to 91% suppression of different parameters in L. aphaca). Maximum inhibition was recorded in germination (36-91%). Significant suppression in leaf count (9-65%), shoot length (12-59%), root length (4-62%), shoot fresh weight (17-71%), root fresh weight (10-60%), shoot dry weight (15-72%), root dry weight (13-64%), and nodule numbers (34-89%) was also observed. The highest inhibition was exhibited by R. stricta followed by C. colocynthis: fruit. However, in case of nodulation maximum suppression was produced by C. burhia extract. Least suppressant activity was observed for the C. polygonides extract. These results encourage the potential use of locally available dry land plants possessing strong allelochemical properties for nonchemical control of weeds ultimately reducing reliance on chemical control.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67277679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}