Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100019
P. Sousa, M.R.A. Mendes, A. Val, M. Teixeira
ABSTRACT: This study aimed to identify and quantify the weed species in an area of organic acerola cultivation in the Distrito de Irrigação dos Tabuleiros Litorâneos do Piauí (DITALPI) in Parnaíba, Piauí, Brazil. Phytosociological sampling was completed in the rainy season, before the farmers adopted management techniques for the plants. Thirty plots of 0.25 m2 were sampled. The plots were located between crop rows, which consisted of herbaceous-subshrub plants. The absolute and relative covers and the absolute and relative frequencies of each species were calculated based on the occurrence and cover of each species. In total, 25 species comprising 13 families were registered, among which the Poaceae family that presented the largest number of species. Commelina benghalensis occurred the most frequently overall. Shannon’s diversity index (H’) and evenness were calculated as 2.30 nats ind-1 and 0.69, respectively. Five species accounted for 79.33% of absolute cover at DITALPI. The species were distributed heterogeneously within the field, and Commelina benghalensis, Urochloa plantaginea, Panicum maximum, Amaranthus spinosus, Cynodonsp., and Cyperus aggregatus were the species most likely to infest the acerola crop. As DITALPI is an area of organic cultivation, understanding these species is essential to help farmers select the best form of control.
摘要:本研究旨在对巴西Parnaíba、Piauí的灌溉区(DITALPI)有机针叶树种植区(DITALPI)杂草种类进行鉴定和量化。在农民采用植物管理技术之前，在雨季完成了植物社会学抽样。选取30块0.25 m2的样地。样地位于作物行间，以草本-亚灌木植物为主。根据各物种的发生和盖度计算各物种的绝对盖度和相对盖度以及绝对盖度和相对盖度。共登记到13科25种，其中以禾本科最多。总体上，本草发生频率最高。Shannon’s多样性指数(H’)为2.30 nats index -1，均匀度为0.69。5种占绝对盖度的79.33%。种属在田间分布呈非均匀性分布，主要有长尾草、车前草、大头草、苋属、金缕苋。和沙蚕是最容易侵染针叶作物的物种。由于DITALPI是一个有机种植区域，了解这些物种对于帮助农民选择最佳的控制方式至关重要。
{"title":"Weed Vegetation Structure in an Area of Organic Acerola Cultivation, Parnaíba, Piauí, Brazil","authors":"P. Sousa, M.R.A. Mendes, A. Val, M. Teixeira","doi":"10.1590/s0100-83582020380100019","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100019","url":null,"abstract":"ABSTRACT: This study aimed to identify and quantify the weed species in an area of organic acerola cultivation in the Distrito de Irrigação dos Tabuleiros Litorâneos do Piauí (DITALPI) in Parnaíba, Piauí, Brazil. Phytosociological sampling was completed in the rainy season, before the farmers adopted management techniques for the plants. Thirty plots of 0.25 m2 were sampled. The plots were located between crop rows, which consisted of herbaceous-subshrub plants. The absolute and relative covers and the absolute and relative frequencies of each species were calculated based on the occurrence and cover of each species. In total, 25 species comprising 13 families were registered, among which the Poaceae family that presented the largest number of species. Commelina benghalensis occurred the most frequently overall. Shannon’s diversity index (H’) and evenness were calculated as 2.30 nats ind-1 and 0.69, respectively. Five species accounted for 79.33% of absolute cover at DITALPI. The species were distributed heterogeneously within the field, and Commelina benghalensis, Urochloa plantaginea, Panicum maximum, Amaranthus spinosus, Cynodonsp., and Cyperus aggregatus were the species most likely to infest the acerola crop. As DITALPI is an area of organic cultivation, understanding these species is essential to help farmers select the best form of 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":"67277816","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/s0100-83582020380100023
A. Kalsing, C. Rossi, F. Lucio, G. B. Minozzi, F. P. Gonçalves, R. Valeriano
ABSTRACT: Spermacoce latifolia, S. verticillata, and Richardia brasiliensis (family Rubiaceae, tribe Spermacoceae) are glyphosate-tolerant weeds in the soybean producing areas of Brazil. The weed shifts to glyphosate-tolerant weeds across soybean-producing areas has shown the need for adoption of practices that conserve the efficacy of glyphosate. This study evaluated the effect of single- and double-knockdown herbicide applications on the control of S. latifolia, S. verticillata, and R. brasiliensis prior to soybean sowing. Trials were designed as a randomized block and treatments were arranged as a factorial. Factor A was three systemic herbicide treatments 10 days before sowing (DBS), while Factor B was three contact herbicide treatments applied 0 DBS (“sow and apply”). The single- and double-knockdown applications were followed by post-emergence applications of glyphosate or 2,4-D + glyphosate when the crop reached three leaves. The efficacy of control of each weed species was visually evaluated 14 days after sowing (DAS), as well as 0 and 28 days after post-emergence application (DAA). The double-knockdown applications generally provided higher levels of control for the target weeds of the Rubiaceae family than the single-knockdown applications. Glyphosate + 2,4-D, glyphosate + 2,4-D + diclosulam or glyphosate + [halauxifen-methyl + diclosulam] followed by glufosinate or paraquat achieved at least 90% of control of S. latifolia and R. brasiliensis, but did not control S. verticillata (<80%). Glufosinate at 457 g a.i. ha-1 was equivalent to paraquat at 400 g a.i. ha-1 as a contact herbicide in the double-knockdown applications, especially on the first assessment dates.
摘要:巴西大豆产区对草甘膦的耐受性较强的杂草为大叶精草(Spermacoce latifolia)、黄花精草(S. verticillata)和巴西理查达(Richardia brasiliensis)。大豆产区杂草向耐草甘膦杂草的转变表明，需要采取措施来保护草甘膦的功效。本研究评价了大豆播前施用单击倒和双击倒除草剂对黑叶蚜、黄斑蚜和巴西栗蚜的防治效果。试验设计为随机分组，治疗按因子排列。因子A是播前10天(DBS)三次系统除草剂处理，因子B是播前10天(DBS)三次接触除草剂处理。在单击倒和双击倒之后，当作物长到三片叶子时，在出苗期施用草甘膦或2,4- d +草甘膦。分别在播种后14天(DAS)、出苗后0天和28天(DAA)目测各杂草的防治效果。双击倒施用通常比单击倒施用对茜草科目标杂草的控制水平更高。草甘膦+ 2,4- d、草甘膦+ 2,4- d +双氯sulam或草甘膦+ [halauxifen-methyl +双氯sulam]再加草甘膦或百草枯，对大叶散叶蝉和巴西散叶蝉的防治效果至少达到90%，但对斑叶散叶蝉的防治效果不佳(<80%)。在双击倒施用中，457 g a.i. ha-1的草铵膦与400 g a.i. ha-1的百草枯作为接触除草剂相当，特别是在第一次评估日期。
{"title":"Efficacy of Control of Glyphosate-Tolerant Species of the Rubiaceae Family Through Double-Knockdown Applications","authors":"A. Kalsing, C. Rossi, F. Lucio, G. B. Minozzi, F. P. Gonçalves, R. Valeriano","doi":"10.1590/s0100-83582020380100023","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100023","url":null,"abstract":"ABSTRACT: Spermacoce latifolia, S. verticillata, and Richardia brasiliensis (family Rubiaceae, tribe Spermacoceae) are glyphosate-tolerant weeds in the soybean producing areas of Brazil. The weed shifts to glyphosate-tolerant weeds across soybean-producing areas has shown the need for adoption of practices that conserve the efficacy of glyphosate. This study evaluated the effect of single- and double-knockdown herbicide applications on the control of S. latifolia, S. verticillata, and R. brasiliensis prior to soybean sowing. Trials were designed as a randomized block and treatments were arranged as a factorial. Factor A was three systemic herbicide treatments 10 days before sowing (DBS), while Factor B was three contact herbicide treatments applied 0 DBS (“sow and apply”). The single- and double-knockdown applications were followed by post-emergence applications of glyphosate or 2,4-D + glyphosate when the crop reached three leaves. The efficacy of control of each weed species was visually evaluated 14 days after sowing (DAS), as well as 0 and 28 days after post-emergence application (DAA). The double-knockdown applications generally provided higher levels of control for the target weeds of the Rubiaceae family than the single-knockdown applications. Glyphosate + 2,4-D, glyphosate + 2,4-D + diclosulam or glyphosate + [halauxifen-methyl + diclosulam] followed by glufosinate or paraquat achieved at least 90% of control of S. latifolia and R. brasiliensis, but did not control S. verticillata (<80%). Glufosinate at 457 g a.i. ha-1 was equivalent to paraquat at 400 g a.i. ha-1 as a contact herbicide in the double-knockdown applications, especially on the first assessment dates.","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":"67277996","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/s0100-83582020380100011
K. Waheed, S. Muhammad, A. Shomaila, Z. Muhammad, U. Izhar, S. Ullah
ABSTRACT: Medicinal Plants have been used throughout the world by human beings as a drug and remedies for various diseases since time immemorial. A study was planned to count into the antimicrobial activity and phytochemical screening of Euphorbia helioscopia. The plants were gathered and tested against some standard strains and some human pathogenic microorganisms i.e Escherichia coli, Bacillus Subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Pseudomonas aeruginosa and three fungal strain Trichoderma, R hizopus nigricans, Aspergillus niger. The concentrations of extracting samples (500 and 1,000 mg mL-1) were used against pathogens. Ciprofloxacin was used as positive control in case of bacterial strains and Colfrimazol was used against the fungal strain while dimethyl sulfoxide as negative control. The outcomes indicated that the positive wells potency of Water extract had a 36 mm diameter of zone of inhibition against Escherichia coli and ethanol extract at 1,000 mg mL-1 had maximum (34 mm) zone of inhibition against Bacillus subtilus (36 mm) zone of inhibition against Klebsiella pneumonia and 33 mm of zone of inhibition against Trichoderma harzianum. Likewise, water extract at a concentration of 1,000 mg mL-1 resulted highest value of zone of inhibition (36 mm) against Staphylococcus aureus, a zone of inhibition ( mm) against Salmonella typhi, 36 mm zone of inhibition against Pseudomonas aeruginosa, (32 mm) zone of inhibition against Rhizopus nigricans, a 34 mm zone of inhibition against Acremonium and (34 mm) zone of inhibition against Aspergillus niger. The most susceptible bacteria were K. pneumonia and Bacillus subtilis, while E. coli was the most resistant bacteria and showed zone of inhibition. The ethanolic extract had tannins, lipid, total proteins, carbohydrates, flavonoids, Alkaloid and polyphenolics.
{"title":"Antimicrobial Activity and Phytochemical Screening of Euphorbia helioscopia","authors":"K. Waheed, S. Muhammad, A. Shomaila, Z. Muhammad, U. Izhar, S. Ullah","doi":"10.1590/s0100-83582020380100011","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100011","url":null,"abstract":"ABSTRACT: Medicinal Plants have been used throughout the world by human beings as a drug and remedies for various diseases since time immemorial. A study was planned to count into the antimicrobial activity and phytochemical screening of Euphorbia helioscopia. The plants were gathered and tested against some standard strains and some human pathogenic microorganisms i.e Escherichia coli, Bacillus Subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Pseudomonas aeruginosa and three fungal strain Trichoderma, R hizopus nigricans, Aspergillus niger. The concentrations of extracting samples (500 and 1,000 mg mL-1) were used against pathogens. Ciprofloxacin was used as positive control in case of bacterial strains and Colfrimazol was used against the fungal strain while dimethyl sulfoxide as negative control. The outcomes indicated that the positive wells potency of Water extract had a 36 mm diameter of zone of inhibition against Escherichia coli and ethanol extract at 1,000 mg mL-1 had maximum (34 mm) zone of inhibition against Bacillus subtilus (36 mm) zone of inhibition against Klebsiella pneumonia and 33 mm of zone of inhibition against Trichoderma harzianum. Likewise, water extract at a concentration of 1,000 mg mL-1 resulted highest value of zone of inhibition (36 mm) against Staphylococcus aureus, a zone of inhibition ( mm) against Salmonella typhi, 36 mm zone of inhibition against Pseudomonas aeruginosa, (32 mm) zone of inhibition against Rhizopus nigricans, a 34 mm zone of inhibition against Acremonium and (34 mm) zone of inhibition against Aspergillus niger. The most susceptible bacteria were K. pneumonia and Bacillus subtilis, while E. coli was the most resistant bacteria and showed zone of inhibition. The ethanolic extract had tannins, lipid, total proteins, carbohydrates, flavonoids, Alkaloid and polyphenolics.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"9 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278099","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/s0100-83582020380100038
T. Ahmad, A. Tanveer, M. Nadeem, M. Yaseen
ABSTRACT: A study focusing on different field capacity levels was planned in the Weed Science Lab, Department of Agronomy, University of Agriculture Faisalabad. Fresh alligatorweed was harvested from the Agronomy fields and cuttings (2 cm length) were made from it. These cuttings were placed at 25%, 50%, 75% and 100% field capacity levels in pots for 25 days. The results of the experiments revealed that at all field capacity levels, fragments of alligatorweed were able to sprout and grow. Increased moisture levels significantly increased the emergence ability and survival of the alligatorweed plants upto a certain level. Compared with the control (25% FC), emergence time of the sprouts in the maximum moisture regime (100% of FC) decreased by 40% (12.94 days vs.7.17 days). By contrast, the survival rate of the fragments decreased by 60% (5 vs. 1.75) although survival and growth rate increased at first with 50% FC and 75% FC. Maximum sprouting and growth were found at 50% field capacity. Field capacity does affect the sprouting capacity of alligatorweed fragments but it has only a little influence on growth parameters. The results suggest that alligatorweed can sustain dry conditions to a great extent and also has the ability to sprout and grow in fully submerged soils.
摘要:在费萨拉巴德农业大学农学系杂草科学实验室开展了一项针对不同田间能力水平的研究。从农艺学领域收获新鲜的鳄鱼草，并将其切成2厘米长的插条。这些岩屑以25%、50%、75%和100%的田间容量水平放置在花盆中，持续25天。实验结果表明，在所有的田间容量水平下，鳄鱼草的碎片都能够发芽和生长。水分水平的提高在一定程度上显著提高了短吻鳄草的出苗率和成活率。与对照(25% FC)相比，最大水分条件下(100% FC)芽的出苗期缩短了40% (12.94 d vs.7.17 d)。相比之下，尽管在50%和75% FC的情况下，最初的存活率和生长率都有所增加，但片段的存活率下降了60%(5比1.75)。在田间容量为50%时萌发和生长最大。田间容量对短吻鳄草叶片的发芽量有影响，但对生长参数影响不大。结果表明，短吻鳄草能够在很大程度上维持干燥条件，并具有在完全浸没的土壤中发芽生长的能力。
{"title":"Modeling the Emergence and Growth of Alligatorweed at Different Field Capacity Levels","authors":"T. Ahmad, A. Tanveer, M. Nadeem, M. Yaseen","doi":"10.1590/s0100-83582020380100038","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100038","url":null,"abstract":"ABSTRACT: A study focusing on different field capacity levels was planned in the Weed Science Lab, Department of Agronomy, University of Agriculture Faisalabad. Fresh alligatorweed was harvested from the Agronomy fields and cuttings (2 cm length) were made from it. These cuttings were placed at 25%, 50%, 75% and 100% field capacity levels in pots for 25 days. The results of the experiments revealed that at all field capacity levels, fragments of alligatorweed were able to sprout and grow. Increased moisture levels significantly increased the emergence ability and survival of the alligatorweed plants upto a certain level. Compared with the control (25% FC), emergence time of the sprouts in the maximum moisture regime (100% of FC) decreased by 40% (12.94 days vs.7.17 days). By contrast, the survival rate of the fragments decreased by 60% (5 vs. 1.75) although survival and growth rate increased at first with 50% FC and 75% FC. Maximum sprouting and growth were found at 50% field capacity. Field capacity does affect the sprouting capacity of alligatorweed fragments but it has only a little influence on growth parameters. The results suggest that alligatorweed can sustain dry conditions to a great extent and also has the ability to sprout and grow in fully submerged soils.","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":"67278485","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/s0100-83582020380100056
Alessandra C. Francischini, J. Constantin, Willian D. Matte, Rubem S. Oliveira Jr., Fellipe G. Machado, Felipe K. Morota
Information about the residual activity of herbicides sprayed in the control of cotton stalks and its potential to affect the development and productivity of corn sown in the following crop are limited. The objective of this work was to identify the carryover effect promoted by the single and sequential application of herbicides used in the control of cotton stalks and to estimate the plant-back for corn sowing. Two trials were carried out simultaneously in a greenhouse, one for a single application and one for a sequential application of herbicides treatments. It was used a 15 x 5 factorial scheme, in a randomized block design with four replicates. The first factor was composed of herbicide treatments and the second factor of five sowing seasons after the application (0, 30, 60, 90 and 120 days). The experimental plots were composed of plastic pots with a capacity of 3 dm filled with loamy soil (470 g kg clay), dried and sieved. The herbicides sprayed were 2,4-D, glyphosate, saflufenacil, [imazapic + imazapyr], dicamba, fluroxypyr, and sulfentrazone. The sequential application of most treatments provided an increase in the residual activity of the evaluated herbicides. The 2,4-D (1,340 g ha), 2,4-D + glyphosate (1,340 + 720 g ha) and 2,4-D + glyphosate + saflufenacil (1,340 + 720 + 105 g ha) presented the shortest safety intervals and were those that presented the lowest risk of affecting the corn sown in succession, even in sequential applications. However, the treatments that consisted of association with herbicides with higher residual activity in the soil such as dicamba, fluroxypyr, sulfentrazone and [imazapic + imazapyr], presented higher carryover potential for corn crop, being observed a safety interval greater than 94 days after sequential application of
在棉花秸秆控制中喷洒的除草剂残留活性及其对后续作物中播种的玉米发育和生产力的潜在影响的信息有限。本研究的目的是确定单次和连续施用除草剂对棉秆控制的携带效应，并估计玉米播种时的植株回潮。在温室中同时进行了两项试验，一项是单次施用，另一项是连续施用除草剂。采用15 x 5因子方案，随机区组设计，共4个重复。第一因子由除草剂处理组成，第二因子由施用后5个播种季节(0、30、60、90和120 d)组成。试验田由容量为3公克的塑料盆组成，罐内填满壤土(470克千克粘土)，晾干并筛分。喷洒的除草剂为2,4- d、草甘膦、氟虫腈、伊马唑吡酯+伊马唑吡酯、麦草畏、氟虫腈和磺胺曲酮。大多数处理的顺序施用都增加了所评价除草剂的残留活性。2,4- d (1,340 g ha)、2,4- d +草甘膦(1,340 + 720 g ha)和2,4- d +草甘膦+氟虫腈(1,340 + 720 + 105 g ha)的安全间隔最短，对玉米连续播种的影响风险最低，即使是连续施用。然而，与土壤中残留活性较高的除草剂(如麦草畏、氟虫腈、磺胺曲酮和[imazapic + imazapyr])联合使用的处理对玉米作物具有更高的携带潜力，连续施用后的安全间隔大于94天
{"title":"Carryover of herbicides used in cotton stalk control on soybean cultivated in succession","authors":"Alessandra C. Francischini, J. Constantin, Willian D. Matte, Rubem S. Oliveira Jr., Fellipe G. Machado, Felipe K. Morota","doi":"10.1590/s0100-83582020380100056","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100056","url":null,"abstract":"Information about the residual activity of herbicides sprayed in the control of cotton stalks and its potential to affect the development and productivity of corn sown in the following crop are limited. The objective of this work was to identify the carryover effect promoted by the single and sequential application of herbicides used in the control of cotton stalks and to estimate the plant-back for corn sowing. Two trials were carried out simultaneously in a greenhouse, one for a single application and one for a sequential application of herbicides treatments. It was used a 15 x 5 factorial scheme, in a randomized block design with four replicates. The first factor was composed of herbicide treatments and the second factor of five sowing seasons after the application (0, 30, 60, 90 and 120 days). The experimental plots were composed of plastic pots with a capacity of 3 dm filled with loamy soil (470 g kg clay), dried and sieved. The herbicides sprayed were 2,4-D, glyphosate, saflufenacil, [imazapic + imazapyr], dicamba, fluroxypyr, and sulfentrazone. The sequential application of most treatments provided an increase in the residual activity of the evaluated herbicides. The 2,4-D (1,340 g ha), 2,4-D + glyphosate (1,340 + 720 g ha) and 2,4-D + glyphosate + saflufenacil (1,340 + 720 + 105 g ha) presented the shortest safety intervals and were those that presented the lowest risk of affecting the corn sown in succession, even in sequential applications. However, the treatments that consisted of association with herbicides with higher residual activity in the soil such as dicamba, fluroxypyr, sulfentrazone and [imazapic + imazapyr], presented higher carryover potential for corn crop, being observed a safety interval greater than 94 days after sequential application of","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"31 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67278745","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/s0100-83582020380100059
S. R. Marchi, Ricardo F. Marques, Rodrigo M. Souza, Cristina F. Justo, C. C. Martins
Background: Talquezal (Paspalum virgatum L.) has become one of the main pasture weeds due to its association with the Urochloa brizantha death syndrome, a disease that causes the progressive death of clumps of susceptible grasses in patches, which leads to weed colonization and pasture degradation. Understanding the weed emergence pattern is essential in decision making for management strategies. Objective: Thus, this study aimed to evaluate the emergence pattern of talquezal seedlings according to its origin and the amount of straw covering the soil. Methods: The experiment was carried out in a greenhouse in a completely randomized design, with six replications and treatments arranged in an 8 × 3 factorial scheme with eight amounts of Urochloa brizantha straw covering the seeds (0, 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 ton ha-1) and three collection sites (Rondonópolis, Redenção, and Cacoal). The effect of the origin and amount of straw was evaluated by the percentage of emergence, relative emergence frequency, mean emergence time, emergence synchrony, and emergence speed index of seedlings obtained over 35 days after sowing. Results: Talquezal seeds showed high seedling emergence vigor regardless of their origin under amounts of straw lower than 4.0 ton ha-1. Conclusions: The result suggests that the amounts of U. brizantha straw higher than 4.0 ton ha-1 on the soil surface, the lower is the percentage of Talquezal seedling emergence.
背景:Talquezal (Paspalum virgatum L.)已成为主要的牧草杂草之一，因为它与尿斑草死亡综合征有关，尿斑草死亡综合征是一种导致斑块中易感草团逐渐死亡的疾病，导致杂草定植和牧场退化。了解杂草的出现模式对制定管理策略至关重要。目的:根据talquezal的产地和覆盖土壤的秸秆数量，评价talquezal幼苗的出苗规律。方法:采用完全随机设计，在温室内进行试验，6个重复，按8 × 3因子设计，8个处理量(0、0.5、1.0、2.0、4.0、6.0、8.0和10.0 ton ha-1)覆盖8个种子，3个采集点(Rondonópolis、reden o和Cacoal)。通过播种后35 d的幼苗出苗率、相对出苗率、平均出苗率、出苗率同步性和出苗率指数来评价秸秆来源和用量的影响。结果:在低于4.0 t hm -1的秸秆用量下，不同产地的Talquezal种子均表现出较高的出苗活力。结论:结果表明，土壤表面喷施玉米秸秆量大于4.0 t hm -1时，Talquezal苗出苗率越低。
{"title":"Straw interference in the emergence of talquezal seeds from different origins","authors":"S. R. Marchi, Ricardo F. Marques, Rodrigo M. Souza, Cristina F. Justo, C. C. Martins","doi":"10.1590/s0100-83582020380100059","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100059","url":null,"abstract":"Background: Talquezal (Paspalum virgatum L.) has become one of the main pasture weeds due to its association with the Urochloa brizantha death syndrome, a disease that causes the progressive death of clumps of susceptible grasses in patches, which leads to weed colonization and pasture degradation. Understanding the weed emergence pattern is essential in decision making for management strategies. Objective: Thus, this study aimed to evaluate the emergence pattern of talquezal seedlings according to its origin and the amount of straw covering the soil. Methods: The experiment was carried out in a greenhouse in a completely randomized design, with six replications and treatments arranged in an 8 × 3 factorial scheme with eight amounts of Urochloa brizantha straw covering the seeds (0, 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 ton ha-1) and three collection sites (Rondonópolis, Redenção, and Cacoal). The effect of the origin and amount of straw was evaluated by the percentage of emergence, relative emergence frequency, mean emergence time, emergence synchrony, and emergence speed index of seedlings obtained over 35 days after sowing. Results: Talquezal seeds showed high seedling emergence vigor regardless of their origin under amounts of straw lower than 4.0 ton ha-1. Conclusions: The result suggests that the amounts of U. brizantha straw higher than 4.0 ton ha-1 on the soil surface, the lower is the percentage of Talquezal seedling emergence.","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":"67278831","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/s0100-83582020380100050
D. Agostinetto, N. Westendorff, R. R. Zandoná, A. Ulguim, A. Langaro
ABSTRACT: Raphanus raphanistrum L. (wild radish) stands out among the weeds that cause greatest damage to the sunflower crop, due to the development cycle and adaptability. The objective of this research was to determine interference periods of sunflower interacting with wild radish, and the effects of competition on yield and its components. The experiment was conducted in the field in a randomized block design with four replications. The treatments were arranged in a factorial design with factor A composed of wild radish coexistence or control in sunflower, and factor B, for eight periods (0, 7, 14, 21, 28, 35, 42 and 135 days after crop emergence). It was evaluated height, diameter of chapters, achene yield and dry matter of weeds and crop. The presence of wild radish adversely affects the accumulation of dry mass, head diameter, thousand grain weight and reduces sunflower productivity when the wild radish interacts during the whole crop cycle, but does not affect on plant height. Chemical control of wild radish may be adopted at the end of period prior to interference, which for sunflower crop is 13 DAE, and the application is sufficient to avoid weed interference until the end of the total period of interference prevention which occurs until 17 days after crop emergence.
{"title":"Interference Periods of Raphanus raphanistrum L. in Sunflower Crop","authors":"D. Agostinetto, N. Westendorff, R. R. Zandoná, A. Ulguim, A. Langaro","doi":"10.1590/s0100-83582020380100050","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100050","url":null,"abstract":"ABSTRACT: Raphanus raphanistrum L. (wild radish) stands out among the weeds that cause greatest damage to the sunflower crop, due to the development cycle and adaptability. The objective of this research was to determine interference periods of sunflower interacting with wild radish, and the effects of competition on yield and its components. The experiment was conducted in the field in a randomized block design with four replications. The treatments were arranged in a factorial design with factor A composed of wild radish coexistence or control in sunflower, and factor B, for eight periods (0, 7, 14, 21, 28, 35, 42 and 135 days after crop emergence). It was evaluated height, diameter of chapters, achene yield and dry matter of weeds and crop. The presence of wild radish adversely affects the accumulation of dry mass, head diameter, thousand grain weight and reduces sunflower productivity when the wild radish interacts during the whole crop cycle, but does not affect on plant height. Chemical control of wild radish may be adopted at the end of period prior to interference, which for sunflower crop is 13 DAE, and the application is sufficient to avoid weed interference until the end of the total period of interference prevention which occurs until 17 days after crop emergence.","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":"67278991","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/s0100-83582020380100052
T. Anjum, Rasheda Jabeen, S. Adkins, W. Akram
Background:Parthenium weed (Parthenium hysterophorus L.) is an invasive weed that has invaded vast regions of Pakistan in a relatively very short period of a decade or two, threatening the crop fields of the agrarian fed country. Parthenium hysterophorus L. is native of central South America and Gulf of Mexico, has now turned out to be a weed of global significance due to its alarming invasions and profuse spread in approximately all parts of the world. Its invasion is probably due to the contamination of its seeds in the imported grains from other countries of the world.Objective:During comprehensive sampling from Pakistan and Australia, it was observed that parthenium weed accessions exhibited several distinct morphological features present at different geographical regions. Therefore this study focuses on the use of plastid DNA barcodes (psbA-trnH) to evaluate the extent of variations in nucleotide sequences between the parthenium weed sampled accessions.Methods:The variability or genetic diversity was evaluated through sequencing of the amplified products and data was subjected to phylogenetic analysis in Molecular Evolutionary Genetic Analysis (MEGA; version 6.06) software.Results:In Maximum Likelihood tree, mainly two clades with three subdivisions are evident which showed increased heterogenity. The results of sequence based markers showed 12 haplotypes of P.hysterophorus populations (having two parsimony informative sites) with 10 indels and a few SNPs (single nucleotide polymorphisms).
{"title":"Exploring Parthenium weed biotypes by chloroplast DNA barcode analysis","authors":"T. Anjum, Rasheda Jabeen, S. Adkins, W. Akram","doi":"10.1590/s0100-83582020380100052","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100052","url":null,"abstract":"Background:Parthenium weed (Parthenium hysterophorus L.) is an invasive weed that has invaded vast regions of Pakistan in a relatively very short period of a decade or two, threatening the crop fields of the agrarian fed country. Parthenium hysterophorus L. is native of central South America and Gulf of Mexico, has now turned out to be a weed of global significance due to its alarming invasions and profuse spread in approximately all parts of the world. Its invasion is probably due to the contamination of its seeds in the imported grains from other countries of the world.Objective:During comprehensive sampling from Pakistan and Australia, it was observed that parthenium weed accessions exhibited several distinct morphological features present at different geographical regions. Therefore this study focuses on the use of plastid DNA barcodes (psbA-trnH) to evaluate the extent of variations in nucleotide sequences between the parthenium weed sampled accessions.Methods:The variability or genetic diversity was evaluated through sequencing of the amplified products and data was subjected to phylogenetic analysis in Molecular Evolutionary Genetic Analysis (MEGA; version 6.06) software.Results:In Maximum Likelihood tree, mainly two clades with three subdivisions are evident which showed increased heterogenity. The results of sequence based markers showed 12 haplotypes of P.hysterophorus populations (having two parsimony informative sites) with 10 indels and a few SNPs (single nucleotide polymorphisms).","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":"67279067","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/s0100-83582020380100066
M. Motamedi, H. Karimmojeni, Fatemeh G. Sini
Background: Allelopathic plants like safflower (Carthamus tinctorius) can be considered as natural herbicides for weeds management in field. But there is not enough research on safflower genotypes allelopathy potential. Objective: So in this study, allelopathic effect of the four safflower genotypes on weeds (Amaranthus sp., Hordeum spontaneum), crops (Sesamum indicum, Triticum aestivum) and on autotoxicity of Carthamus tinctorius was evaluated in bioassay using sandwich method. The results can be used in the management of weeds in safflower fields and also in the rotation with other crops. Methods: Two genotypes with high allelopathic potential and two genotypes with low allelopathic potential were selected from forty genotypes of safflower. Growth traits including radicle length, hypocotyl length, shoot length, fresh biomass weight and germination percentages were measured. Results: Results showed that Amaranthus sp. and C. tinctorius displayed the most and least susceptibility to safflower residues, respectively. Khorasan (Khorasan330) and Egypt (PI657800) had the greatest with Kerman (CTNIR9) and Australia (PI 262424) had the least inhibitory effects on target plants. PI 262424 stimulated hypocotyl growth by 51%, 18% and 7% in H. spontaneum, T. aestivum and C. tinctorius, respectively. CTNIR9 enhanced this trait by 16% in T. aestivum and 10% in C. tinctorius. In large-seeded species (H. spontaneum, T. aestivum and C. tinctorius, Kerman (CTNIR9) and Australia (PI 262424) stimulated seedling growth. Conclusion: It can be concluded that effectiveness of allelopathic residues of safflower on target plants depended on the seed size of target plant with smaller seed size (Amaranthus sp.) were more susceptible to allelopathic residues than those with larger ones. In addition radicle length was affected more than other growth traits by safflower residues. SBCPD | Planta Daninha Motamedi M, Karimmojeni H, and Sini FG. Allopathic potential of safflower genotypes Planta Daninha 2020;38:e020212334 https://doi.org/10.1590/S0100-83582020380100066 2/8
背景:红花(Carthamus tinctorius)等化感植物可作为田间杂草管理的天然除草剂。但目前对红花基因型化感作用潜力的研究还不够。目的:采用夹心法测定4种红花基因型对杂草(苋菜、禾锦)、作物(芝麻、小麦)和红花(红花)的化感作用。该结果可用于红花田杂草的管理，也可用于与其他作物的轮作。方法:从40个红花基因型中选择2个高化感电位基因型和2个低化感电位基因型。测定了根长、下胚轴长、茎长、鲜生物量和发芽率等生长性状。结果:红苋菜(Amaranthus sp.)对红花残留的敏感性最高，对红花残留的敏感性最低;呼罗珊(Khorasan330)和埃及(PI657800)对目标植物的抑制作用最大，克尔曼(CTNIR9)和澳大利亚(pi262424)对目标植物的抑制作用最小。pi262424分别对自发黄颡鱼、黄颡鱼和黄颡鱼的下胚轴生长有51%、18%和7%的促进作用。CTNIR9在T. aestivum和C. tinctorius中分别提高了16%和10%。在大种子种(H. spontanum, T. aestivum和C. tinctorius)中，Kerman (CTNIR9)和Australia (PI 262424)对幼苗生长有促进作用。结论:红花化感残留物对靶植物的药效与种子大小有关，种子大小较小的靶植物(苋菜)比种子较大的靶植物更易受化感残留物的影响。此外，红花残基对胚根长度的影响大于其他生长性状。[b]植物，Motamedi M, Karimmojeni H，和Sini FG。红花基因型的拮抗作用研究[j]; 2010;38: 020212334 https://doi.org/10.1590/S0100-83582020380100066 2/8
{"title":"Allelopathic effect of Carthamus tinctorius on weeds and crops","authors":"M. Motamedi, H. Karimmojeni, Fatemeh G. Sini","doi":"10.1590/s0100-83582020380100066","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100066","url":null,"abstract":"Background: Allelopathic plants like safflower (Carthamus tinctorius) can be considered as natural herbicides for weeds management in field. But there is not enough research on safflower genotypes allelopathy potential. Objective: So in this study, allelopathic effect of the four safflower genotypes on weeds (Amaranthus sp., Hordeum spontaneum), crops (Sesamum indicum, Triticum aestivum) and on autotoxicity of Carthamus tinctorius was evaluated in bioassay using sandwich method. The results can be used in the management of weeds in safflower fields and also in the rotation with other crops. Methods: Two genotypes with high allelopathic potential and two genotypes with low allelopathic potential were selected from forty genotypes of safflower. Growth traits including radicle length, hypocotyl length, shoot length, fresh biomass weight and germination percentages were measured. Results: Results showed that Amaranthus sp. and C. tinctorius displayed the most and least susceptibility to safflower residues, respectively. Khorasan (Khorasan330) and Egypt (PI657800) had the greatest with Kerman (CTNIR9) and Australia (PI 262424) had the least inhibitory effects on target plants. PI 262424 stimulated hypocotyl growth by 51%, 18% and 7% in H. spontaneum, T. aestivum and C. tinctorius, respectively. CTNIR9 enhanced this trait by 16% in T. aestivum and 10% in C. tinctorius. In large-seeded species (H. spontaneum, T. aestivum and C. tinctorius, Kerman (CTNIR9) and Australia (PI 262424) stimulated seedling growth. Conclusion: It can be concluded that effectiveness of allelopathic residues of safflower on target plants depended on the seed size of target plant with smaller seed size (Amaranthus sp.) were more susceptible to allelopathic residues than those with larger ones. In addition radicle length was affected more than other growth traits by safflower residues. SBCPD | Planta Daninha Motamedi M, Karimmojeni H, and Sini FG. Allopathic potential of safflower genotypes Planta Daninha 2020;38:e020212334 https://doi.org/10.1590/S0100-83582020380100066 2/8","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"44 9 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67279516","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/s0100-83582020380100015
I. Quintero-Pertúz, E. CARBONÓ-DELAHOZ, A. Jarma-Orozco
ABSTRACT: This study was conducted to determine the richness and composition of weed communities associated with banana plantations in Magdalena department, Colombia. Between September 2016 and May 2017, a total of 164 hectares were assessed over four agroecological zones (Alta, Media, Baja and Norte); in each zone, three representative farms were selected where, through zigzag paths, botanical collections were made in cultivated lots. Information on life cycle, growth habit and origin of each species was included. The floristic composition was represented by 204 species distributed among 143 genera and 54 families. Poaceae, with 31 species, was the family with the highest species richness, followed by Fabaceae (12) and Asteraceae (11). From the total species recorded, 113 are perennial (55%) and 91 are annual (45%); 141 species are herbaceous (68%), 38 are climbers (20%), and 25 are arboreal or shrubby (12%). Native species predominate over introduced species. The species richness does not differ significantly between the sampling zones, but the weed community composition does. The presence of common species reported as important weeds worldwide was recorded in the four zones. However, some species were recorded in only one of the zones, generating a differential composition pattern. Comparison with local inventories showed changes in the composition of the weed complex over time. The presence of various species not previously considered weeds in the banana crops of this region is highlighted.
{"title":"Weeds Associated with Banana Crops in Magdalena Department, Colombia","authors":"I. Quintero-Pertúz, E. CARBONÓ-DELAHOZ, A. Jarma-Orozco","doi":"10.1590/s0100-83582020380100015","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100015","url":null,"abstract":"ABSTRACT: This study was conducted to determine the richness and composition of weed communities associated with banana plantations in Magdalena department, Colombia. Between September 2016 and May 2017, a total of 164 hectares were assessed over four agroecological zones (Alta, Media, Baja and Norte); in each zone, three representative farms were selected where, through zigzag paths, botanical collections were made in cultivated lots. Information on life cycle, growth habit and origin of each species was included. The floristic composition was represented by 204 species distributed among 143 genera and 54 families. Poaceae, with 31 species, was the family with the highest species richness, followed by Fabaceae (12) and Asteraceae (11). From the total species recorded, 113 are perennial (55%) and 91 are annual (45%); 141 species are herbaceous (68%), 38 are climbers (20%), and 25 are arboreal or shrubby (12%). Native species predominate over introduced species. The species richness does not differ significantly between the sampling zones, but the weed community composition does. The presence of common species reported as important weeds worldwide was recorded in the four zones. However, some species were recorded in only one of the zones, generating a differential composition pattern. Comparison with local inventories showed changes in the composition of the weed complex over time. The presence of various species not previously considered weeds in the banana crops of this region is highlighted.","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":"67277695","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}
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