Pub Date : 2020-01-01DOI: 10.1590/s0100-83582020380100021
C. Alister, M. Araya, A. Cordova, J. Saavedra, M. Kogan
ABSTRACT: Pesticide soil sorption is a primary factor that influences the fate of pesticides in the environment, affecting regulation of microbiological and chemical degradation, volatilization and leaching. The main goal of this research was to study the effect of the organic phase of volcanic soils on sorption of agricultural pesticides. Sorption and desorption of eight agricultural pesticides were studied on eight volcanic soils that varied in the fulvic and humic constituents of their organic matter. For all pesticides, sorption was well described by a Freundlich isotherm where 1/nads values indicated that the sorption mechanism could be mainly explained by physical reactions in all soils. Kf values for carbaryl and flumioxazin were the highest with average values of 7.78 and 7.16 mL g-1, respectively. By contrast, hexazinone and metsulfuron-methyl had the lowest average Kf: 0.86 and 0.81 mL g-1, respectively, indicating that they were the least attracted to the soils. The organic fraction of the soil was the main soil factor related to the sorption of all study pesticides. Particularly, humic acid content regulated the sorption between pesticide and soil, especially through the carboxylic groups.
摘要:农药在土壤中的吸附作用是影响农药在环境中命运的主要因素，影响农药在土壤中的微生物和化学降解、挥发和淋滤的调控。本研究的主要目的是研究火山土有机相对农业农药吸附的影响。研究了8种不同有机质腐殖质和腐殖质成分的火山土对8种农药的吸附和解吸作用。Freundlich等温线很好地描述了所有农药的吸附，其中1/nads值表明，所有土壤中的吸附机制主要可以用物理反应来解释。西威因和氟恶嗪的Kf值最高，平均值分别为7.78和7.16 mL g-1。而己嗪酮和甲磺隆-甲基的平均Kf最低，分别为0.86和0.81 mL g-1，表明它们对土壤的吸引力最小。土壤有机组分是影响农药吸附的主要土壤因子。特别是腐植酸含量调节了农药与土壤之间的吸附，特别是通过羧基。
{"title":"Humic Substances and their Relation to Pesticide Sorption in Eight Volcanic Soils","authors":"C. Alister, M. Araya, A. Cordova, J. Saavedra, M. Kogan","doi":"10.1590/s0100-83582020380100021","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100021","url":null,"abstract":"ABSTRACT: Pesticide soil sorption is a primary factor that influences the fate of pesticides in the environment, affecting regulation of microbiological and chemical degradation, volatilization and leaching. The main goal of this research was to study the effect of the organic phase of volcanic soils on sorption of agricultural pesticides. Sorption and desorption of eight agricultural pesticides were studied on eight volcanic soils that varied in the fulvic and humic constituents of their organic matter. For all pesticides, sorption was well described by a Freundlich isotherm where 1/nads values indicated that the sorption mechanism could be mainly explained by physical reactions in all soils. Kf values for carbaryl and flumioxazin were the highest with average values of 7.78 and 7.16 mL g-1, respectively. By contrast, hexazinone and metsulfuron-methyl had the lowest average Kf: 0.86 and 0.81 mL g-1, respectively, indicating that they were the least attracted to the soils. The organic fraction of the soil was the main soil factor related to the sorption of all study pesticides. Particularly, humic acid content regulated the sorption between pesticide and soil, especially through the carboxylic groups.","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":"67277925","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/s0100-83582020380100026
J. Gherekhloo, R. Alcántara-de la Cruz, M. D. Osuna, S. Sohrabi, R. Prado
ABSTRACT: Littleseed canarygrass (Phalaris minor) is the second most serious and problematic grass weed in wheat fields in Iran, and has developed resistance to ACCase inhibiting herbicides. Inter-simple sequence repeat (ISSR) analysis was used to assess genetic variation between and within ACCase inhibitor-resistant and susceptible P. minor populations in Iran and to determine the origin of resistance and its dispersal. Sixteen P. minor populations from different regions in Iran were analysed using seven primers. Genetic relationships generated using UPGMA analysis indicated the presence of more than one genotype among the herbicide resistant populations. The results indicated that the high genetic similarity and physical proximity among the resistant P. minor populations in the different regions is mainly due to cross pollination, mechanical seed dispersion and local ecological factors. These findings suggested that independent selection as well as movement of resistant seeds had occurred, which could explain the presence and dispersion of ACCase inhibitor-resistance in these populations.
{"title":"Assessing Genetic Variation and Spread of Phalaris minor Resistant to ACCase Inhibiting Herbicides in Iran","authors":"J. Gherekhloo, R. Alcántara-de la Cruz, M. D. Osuna, S. Sohrabi, R. Prado","doi":"10.1590/s0100-83582020380100026","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100026","url":null,"abstract":"ABSTRACT: Littleseed canarygrass (Phalaris minor) is the second most serious and problematic grass weed in wheat fields in Iran, and has developed resistance to ACCase inhibiting herbicides. Inter-simple sequence repeat (ISSR) analysis was used to assess genetic variation between and within ACCase inhibitor-resistant and susceptible P. minor populations in Iran and to determine the origin of resistance and its dispersal. Sixteen P. minor populations from different regions in Iran were analysed using seven primers. Genetic relationships generated using UPGMA analysis indicated the presence of more than one genotype among the herbicide resistant populations. The results indicated that the high genetic similarity and physical proximity among the resistant P. minor populations in the different regions is mainly due to cross pollination, mechanical seed dispersion and local ecological factors. These findings suggested that independent selection as well as movement of resistant seeds had occurred, which could explain the presence and dispersion of ACCase inhibitor-resistance in these populations.","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":"67278470","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/s0100-83582020380100031
Mehmood-ul-Hassan, A. Qayyum, A. Sher, M. Tahir, M. Azeem, A. Fareed
Tillage practice has a significant role on weeds eradication and soil water conservation in crop production. Under semiarid agriculture, the monsoon rains (65%) are major source of water in Potohar, Pakistan, which can effectively be used mostly for winter crops production. To evaluate the impact of different tillage system for prevailing cropping systems and their weeds biomass under semiarid conditions, field experiment was conducted at the Arid University Research Farm Koont Rawalpindi (Pakistan) during crop growth seasons 2013-14 and 2014-15. Tillage systems as treatments were (a) three cultivations with a cultivator, as control treatment, (b) mold-board with two cultivations, (c) chisel-plough with two cultivations and (d) minimum tillage (only tillage performed at sowing time) with glyphosate. Sowing was made using drill for all cropping systems i.e. a, b, and d except c which was planted on bed (made by bed planter). In addition to ploughing treatments, different cropping systems (a) wheat fallow (b) wheat and brassica fallow, (c) wheat and chickpea fallow and (d) wheat cluster bean (green manure crop) were also used for minimum two years rotations. On average in both study years, interactive effect of treatments (mold board with 2 cultivations) for the rotation wheat and brassica fallow showed a reduction in weeds dry biomass of Anagallis arvensis (blue pimpernel, 55.6%), Asphodelus tenuifolius (jungle onion, 42.3%), Chenopodium album (common goosefoot, 40.8%), Circium arvense (creeping thistle, 53.1%), Convolvulus arvensis (field bind weed, 56.6%) and Cynodon dactylon (vilfa stellata, 45.8%) within 60 days after sowing (DAS) as compared with the control treatment (three cultivations on a wheat fallow cropping system). Similar trends were observed at the crop maturity stage. Results of the experiment showed that better weed biomass suppression can be achieved by using moldboard plough for cultivation with followed by wheatbrassica cropping system and/or wheat chickpea intercropping for semiarid soil condition in Pakistan.
{"title":"Weeds Biomass as Affected by Tillage Practices and Cropping Systems under a Semiarid Environment","authors":"Mehmood-ul-Hassan, A. Qayyum, A. Sher, M. Tahir, M. Azeem, A. Fareed","doi":"10.1590/s0100-83582020380100031","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100031","url":null,"abstract":"Tillage practice has a significant role on weeds eradication and soil water conservation in crop production. Under semiarid agriculture, the monsoon rains (65%) are major source of water in Potohar, Pakistan, which can effectively be used mostly for winter crops production. To evaluate the impact of different tillage system for prevailing cropping systems and their weeds biomass under semiarid conditions, field experiment was conducted at the Arid University Research Farm Koont Rawalpindi (Pakistan) during crop growth seasons 2013-14 and 2014-15. Tillage systems as treatments were (a) three cultivations with a cultivator, as control treatment, (b) mold-board with two cultivations, (c) chisel-plough with two cultivations and (d) minimum tillage (only tillage performed at sowing time) with glyphosate. Sowing was made using drill for all cropping systems i.e. a, b, and d except c which was planted on bed (made by bed planter). In addition to ploughing treatments, different cropping systems (a) wheat fallow (b) wheat and brassica fallow, (c) wheat and chickpea fallow and (d) wheat cluster bean (green manure crop) were also used for minimum two years rotations. On average in both study years, interactive effect of treatments (mold board with 2 cultivations) for the rotation wheat and brassica fallow showed a reduction in weeds dry biomass of Anagallis arvensis (blue pimpernel, 55.6%), Asphodelus tenuifolius (jungle onion, 42.3%), Chenopodium album (common goosefoot, 40.8%), Circium arvense (creeping thistle, 53.1%), Convolvulus arvensis (field bind weed, 56.6%) and Cynodon dactylon (vilfa stellata, 45.8%) within 60 days after sowing (DAS) as compared with the control treatment (three cultivations on a wheat fallow cropping system). Similar trends were observed at the crop maturity stage. Results of the experiment showed that better weed biomass suppression can be achieved by using moldboard plough for cultivation with followed by wheatbrassica cropping system and/or wheat chickpea intercropping for semiarid soil condition in Pakistan.","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":"67278617","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/s0100-83582020380100003
K. Aktas, C. Özdemir, B. Özdemir
ABSTRACT: Verbascum L. is the largest genus of the family Scrophulariceae and includes several species are of medicinal importance. The high morphological diversity among the species of the genus Verbascum causes problems in the delimitation of the species. In this study, morphological, anatomical, palynological and seed properties of Verbascum exuberans were investigated. It is a local endemic restricted to the provinces of Manisa and Izmir in West Anatolia. In the root cross-section, the xylem elements occupy a considerable area. The upper part of the epidermis cells in the stem cross-section is covered a distinct cuticle layer. The main vein of the leaf is shapped as bicollateral bundle. Idioblasts were not observed in the epidermis of the leaves of V. exuberans. Seeds of V. exuberans are dark brown and oblong to prismatic and alveolate. Hilum is short and orbicular. The seed coat ornamentation is reticulate-rugose. Pollen grains usually radially symmetrical, isopolar, prolate, tricolpate. Tectum is reticulate.
{"title":"Morphology, Anatomy, Palynology and Seed Micromorphology of Turkish Endemic Verbascum exuberans Hub.-Mor. (Scrophulariaceae)","authors":"K. Aktas, C. Özdemir, B. Özdemir","doi":"10.1590/s0100-83582020380100003","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100003","url":null,"abstract":"ABSTRACT: Verbascum L. is the largest genus of the family Scrophulariceae and includes several species are of medicinal importance. The high morphological diversity among the species of the genus Verbascum causes problems in the delimitation of the species. In this study, morphological, anatomical, palynological and seed properties of Verbascum exuberans were investigated. It is a local endemic restricted to the provinces of Manisa and Izmir in West Anatolia. In the root cross-section, the xylem elements occupy a considerable area. The upper part of the epidermis cells in the stem cross-section is covered a distinct cuticle layer. The main vein of the leaf is shapped as bicollateral bundle. Idioblasts were not observed in the epidermis of the leaves of V. exuberans. Seeds of V. exuberans are dark brown and oblong to prismatic and alveolate. Hilum is short and orbicular. The seed coat ornamentation is reticulate-rugose. Pollen grains usually radially symmetrical, isopolar, prolate, tricolpate. Tectum is reticulate.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"123 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67277781","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/s0100-83582020380100020
M. O. Cabral, F. Oliveira, L. Dalvi, A. G. Teixeira, L. Rocha, J. Pedrosa
ABSTRACT: The consumption of yacon has been increasing around the world due to the nutritional and pharmaceutical properties of this plant. The growing commercial interest in yacon (Smallanthus sonchifolius) generates a demand for crop management research studies, including the effect of weed competition on yacon, which was not yet studied. Thus, this study was performed with the objective of evaluating the effects of weed competition on yacon development and growth. The experimental design was completely randomized with four treatments and seven replicates. Treatments were yacon with the interference of four weed species: Cyperus rotundus L. (nutgrass), Commelina benghalensis L. (tropical spiderwort), Amaranthus viridis L. (slender amaranth) and Bidens pilosa L. (hairy beggarticks). The experiment was conducted in a greenhouse, using 10 dm3 pots. Plant height, number of leaves, number of stems, leaf area, fresh and dry mass weight (total and partial), and chlorophyll A, B and total were evaluated. The weed competition resulted in a decrease in the yacon development (height, number of leaves, number of stems, leaf area), photosynthetic rate (decreased chlorophyll content A, B and total) and yield, as also decreased the accumulation of fresh and dry biomass of tuberous roots. C. benghalensis L. and A. viridis L. were the weeds most affecting the development and growth of yacon.
{"title":"Influence of Weeds on Yacon Initial Growth and Development","authors":"M. O. Cabral, F. Oliveira, L. Dalvi, A. G. Teixeira, L. Rocha, J. Pedrosa","doi":"10.1590/s0100-83582020380100020","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100020","url":null,"abstract":"ABSTRACT: The consumption of yacon has been increasing around the world due to the nutritional and pharmaceutical properties of this plant. The growing commercial interest in yacon (Smallanthus sonchifolius) generates a demand for crop management research studies, including the effect of weed competition on yacon, which was not yet studied. Thus, this study was performed with the objective of evaluating the effects of weed competition on yacon development and growth. The experimental design was completely randomized with four treatments and seven replicates. Treatments were yacon with the interference of four weed species: Cyperus rotundus L. (nutgrass), Commelina benghalensis L. (tropical spiderwort), Amaranthus viridis L. (slender amaranth) and Bidens pilosa L. (hairy beggarticks). The experiment was conducted in a greenhouse, using 10 dm3 pots. Plant height, number of leaves, number of stems, leaf area, fresh and dry mass weight (total and partial), and chlorophyll A, B and total were evaluated. The weed competition resulted in a decrease in the yacon development (height, number of leaves, number of stems, leaf area), photosynthetic rate (decreased chlorophyll content A, B and total) and yield, as also decreased the accumulation of fresh and dry biomass of tuberous roots. C. benghalensis L. and A. viridis L. were the weeds most affecting the development and growth of yacon.","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":"67277916","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/s0100-83582020380100009
A. Bari, M. S. Baloch, A. Shah, A. Khakwani, I. Hussain, J. Iqbal, A. Ali, M. A. Bukhari
ABSTRACT: In order to examine application of various herbicides for controlling weeds in wheat crop, a field trial was conducted at the Agronomic Research Area, Faculty of Agriculture, Gomal University, Dera Ismail Khan, Khyber Pakhtunkhwa (KPK) during the year 2015-2016. The experiment was laid out in a randomized complete block design (RCBD) with split-plot arrangements having three replications. The main plot was comprised application time of herbicides while the use of herbicides was assigned to sub-plots. The data revealed that most of the weed parameters, physiological traits and agronomic attributes of crop plants were significantly affected by weed management practices including the use of herbicides at different time intervals over the weedy check. Hand weeding technique excelled all other weed management practices in almost all the parameters studied. This technique was found to be the most effective treatment against all prevailing weeds and obtained the highest grain yield of wheat under climatic conditions of Dera Ismail Khan.
{"title":"Application of Various Herbicides on Controlling Large and Narrow Leaf Weeds and Their Effects on Physiological and Agronomic Traits of Wheat","authors":"A. Bari, M. S. Baloch, A. Shah, A. Khakwani, I. Hussain, J. Iqbal, A. Ali, M. A. Bukhari","doi":"10.1590/s0100-83582020380100009","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100009","url":null,"abstract":"ABSTRACT: In order to examine application of various herbicides for controlling weeds in wheat crop, a field trial was conducted at the Agronomic Research Area, Faculty of Agriculture, Gomal University, Dera Ismail Khan, Khyber Pakhtunkhwa (KPK) during the year 2015-2016. The experiment was laid out in a randomized complete block design (RCBD) with split-plot arrangements having three replications. The main plot was comprised application time of herbicides while the use of herbicides was assigned to sub-plots. The data revealed that most of the weed parameters, physiological traits and agronomic attributes of crop plants were significantly affected by weed management practices including the use of herbicides at different time intervals over the weedy check. Hand weeding technique excelled all other weed management practices in almost all the parameters studied. This technique was found to be the most effective treatment against all prevailing weeds and obtained the highest grain yield of wheat under climatic conditions of Dera Ismail Khan.","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":"67277984","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/s0100-83582020380100013
V. Takeshita, K. F. Mendes, R. F. Pimpinato, V. L. Tornisielo
ABSTRACT: Materials with high organic carbon content are studied for the removal of herbicides from water, such as activated carbon. Low cost alternatives should be investigated for the substitution of this type of material in the removal of herbicides from water. In this context, the aim of this research was to evaluate four agro-industrial residues (white grape bagasse, corn straw, peanut shell and soybean hull) as adsorbents of diuron and hexazinone in drinking water. Samples of drinking water were collected from sources used for human consumption. Five concentrations (1, 2, 3, 4 and 5 mg mL-1) of each herbicide were added to the potable water samples. Each experimental unit consisted of 10 mL of a solution of water and herbicide with 0.1 g of each agro-industrial residue. Sorption was evaluated using the batch equilibrium method. High performance liquid chromatography (HPLC) was used to determine the amount of herbicide present in the aqueous solution. The Kf (Freundlich coefficient) of diuron was higher (2.99-11.93 mmol(1-1/n) L1/n kg-1) than hexazinone (2.31-4.61 mmol(1-1/n) L1/n kg-1) for all adsorbents used. Diuron percentage sorption was higher with white grape bagasse (51.15%) and peanut husk (52.44%), and hexazinone with corn straw (22.77%) and white grape marc (21.48%), than other agro-industrial waste for both herbicides. Even though the sorption of diuron was more pronounced than that of hexazinone, the sorption values obtained in this study were less than 52.44% and considered unsatisfactory in terms of effective removal from contaminated water.
{"title":"Adsorption Isotherms of Diuron and Hexazinone in Drinking Water Using Four Agro-Industrial Residues","authors":"V. Takeshita, K. F. Mendes, R. F. Pimpinato, V. L. Tornisielo","doi":"10.1590/s0100-83582020380100013","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100013","url":null,"abstract":"ABSTRACT: Materials with high organic carbon content are studied for the removal of herbicides from water, such as activated carbon. Low cost alternatives should be investigated for the substitution of this type of material in the removal of herbicides from water. In this context, the aim of this research was to evaluate four agro-industrial residues (white grape bagasse, corn straw, peanut shell and soybean hull) as adsorbents of diuron and hexazinone in drinking water. Samples of drinking water were collected from sources used for human consumption. Five concentrations (1, 2, 3, 4 and 5 mg mL-1) of each herbicide were added to the potable water samples. Each experimental unit consisted of 10 mL of a solution of water and herbicide with 0.1 g of each agro-industrial residue. Sorption was evaluated using the batch equilibrium method. High performance liquid chromatography (HPLC) was used to determine the amount of herbicide present in the aqueous solution. The Kf (Freundlich coefficient) of diuron was higher (2.99-11.93 mmol(1-1/n) L1/n kg-1) than hexazinone (2.31-4.61 mmol(1-1/n) L1/n kg-1) for all adsorbents used. Diuron percentage sorption was higher with white grape bagasse (51.15%) and peanut husk (52.44%), and hexazinone with corn straw (22.77%) and white grape marc (21.48%), than other agro-industrial waste for both herbicides. Even though the sorption of diuron was more pronounced than that of hexazinone, the sorption values obtained in this study were less than 52.44% and considered unsatisfactory in terms of effective removal from contaminated water.","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":"67278145","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/s0100-83582020380100053
S. Ashfaq, Mushtaq Ahmad, M. Zafar, S. Sultana, Moona Nazish, A. N. Khan
electron microscope (SEM). Results: Variations were observed in both the weeds, i.e Convolvulus arvensis (bindweeds) and Convolvulus prostatus (soft bindweed) in epidermal cells, stomatal size and number, guard cell shape and size, subsidiary cell and diversity of trichomes. Paracytic type of stomata was found in both the weed species. Stomata shape in Convolvulus is elliptical and oval to oval oblong in Convolvulus prostratus species have a and exine ornamentation. type was
{"title":"Systematics of medicinally important weeds of genus Convolvulus: Convolvulaceae","authors":"S. Ashfaq, Mushtaq Ahmad, M. Zafar, S. Sultana, Moona Nazish, A. N. Khan","doi":"10.1590/s0100-83582020380100053","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100053","url":null,"abstract":"electron microscope (SEM). Results: Variations were observed in both the weeds, i.e Convolvulus arvensis (bindweeds) and Convolvulus prostatus (soft bindweed) in epidermal cells, stomatal size and number, guard cell shape and size, subsidiary cell and diversity of trichomes. Paracytic type of stomata was found in both the weed species. Stomata shape in Convolvulus is elliptical and oval to oval oblong in Convolvulus prostratus species have a and exine ornamentation. type was","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":"67279132","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/s0100-83582020380100016
G. M. Chitolina, K. F. Mendes, C. S. Almeida, F. Alonso, L. Junqueira, V. L. Tornisielo
ABSTRACT: Herbicides with a high leaching capacity, such as hexazinone, tend to reach deeper soils more easily, where retention of the product affects its availability in the soil solution. Therefore, it is important to understand the behavior of hexazinone at a variety of soil depths. The objective of this research was to evaluate the sorption and desorption of hexazinone throughout the soil profile. The sorption and desorption processes of 14C-hexazinone [triazine-6-14C] at three soil depths (0-10, 10-20, and 20-30 cm) were evaluated by the equilibrium batch method, and the radioactivity of the herbicide was quantified by liquid scintillation spectrometry. Five different concentrations of hexazinone (0.12, 0.19, 0.25, 0.31, and 0.38 µg mL-1) in a methanol solvent were used. The concentrations of the herbicide in equilibrium and sorbed in the soil were adjusted by using isotherms according to the Linear, Freundlich, and Langmuir models. Hexazinone sorption at soil depths of 0-10, 10-20, and 20-30 cm showed decreasing Freundlich coefficients (Kf) with values of 0.18, 0.11, and 0.08 g (1-1/n) L1/n kg-1 (50.49, 47.58, and 46.37% sorbed), and in the desorption the Kf were 7.96, 7.93, and 9.82 g (1-1/n) L1/n kg-1 (26.17, 26.58, and 28.68% desorbed), respectively. The small difference in organic carbon content between soil depths was sufficient to affect hexazinone retention, interfering with the bioavailability of this product in the soil solution for weed control.
摘要:具有高浸出能力的除草剂，如己嗪酮，往往更容易深入土壤深层，其残留影响其在土壤溶液中的有效性。因此，了解己嗪酮在不同土壤深度下的行为是很重要的。本研究的目的是评价己嗪酮在整个土壤剖面上的吸附和解吸。采用平衡批法评价了14c -己嗪酮[三嗪-6- 14c]在3个土壤深度(0-10、10-20和20-30 cm)上的吸附和解吸过程，并采用液体闪烁光谱法测定了该除草剂的放射性。在甲醇溶剂中使用五种不同浓度的己嗪酮(0.12、0.19、0.25、0.31和0.38µg mL-1)。根据线性模型、Freundlich模型和Langmuir模型，利用等温线对平衡态和土壤吸收的除草剂浓度进行了调整。在0-10、10-20和20-30 cm土壤深度，已吸附的Hexazinone Freundlich系数(Kf)分别为0.18、0.11和0.08 g (1-1/n) L1/n kg-1(被吸附的50.49、47.58和46.37%)，Freundlich系数(Kf)分别为7.96、7.93和9.82 g (1-1/n) L1/n kg-1(被解吸的26.17、26.58和28.68%)。土壤深度之间有机碳含量的微小差异足以影响己嗪酮的保留率，干扰该产品在土壤溶液中的生物利用度。
{"title":"Influence of Soil Depth on Sorption and Desorption Processes of Hexazinone","authors":"G. M. Chitolina, K. F. Mendes, C. S. Almeida, F. Alonso, L. Junqueira, V. L. Tornisielo","doi":"10.1590/s0100-83582020380100016","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100016","url":null,"abstract":"ABSTRACT: Herbicides with a high leaching capacity, such as hexazinone, tend to reach deeper soils more easily, where retention of the product affects its availability in the soil solution. Therefore, it is important to understand the behavior of hexazinone at a variety of soil depths. The objective of this research was to evaluate the sorption and desorption of hexazinone throughout the soil profile. The sorption and desorption processes of 14C-hexazinone [triazine-6-14C] at three soil depths (0-10, 10-20, and 20-30 cm) were evaluated by the equilibrium batch method, and the radioactivity of the herbicide was quantified by liquid scintillation spectrometry. Five different concentrations of hexazinone (0.12, 0.19, 0.25, 0.31, and 0.38 µg mL-1) in a methanol solvent were used. The concentrations of the herbicide in equilibrium and sorbed in the soil were adjusted by using isotherms according to the Linear, Freundlich, and Langmuir models. Hexazinone sorption at soil depths of 0-10, 10-20, and 20-30 cm showed decreasing Freundlich coefficients (Kf) with values of 0.18, 0.11, and 0.08 g (1-1/n) L1/n kg-1 (50.49, 47.58, and 46.37% sorbed), and in the desorption the Kf were 7.96, 7.93, and 9.82 g (1-1/n) L1/n kg-1 (26.17, 26.58, and 28.68% desorbed), respectively. The small difference in organic carbon content between soil depths was sufficient to affect hexazinone retention, interfering with the bioavailability of this product in the soil solution for weed 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":"67277716","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/s0100-83582020380100017
A.L.V. Nascimento, Gustavo A. M. Pereira, L. F. Pucci, D. P. Alves, C. A. Gomes, M. R. Reis
ABSTRACT: The presence of weeds in cabbage cultivation areas causes a reduction in the productivity and quality of the commercial product. Given the difficulties in management and the scarcity of registered products for weed control in cabbage cultivation, this study aimed to evaluate the tolerance of the cabbage cultivars Astrus Plus to the herbicides 2,4-D and dicamba. Two experiments were performed; one under controlled conditions and another conducted in the field. The efficacy of the herbicides on the initial growth of the crop was evaluated in the first experiment, measuring the dry matter of the aerial part, the root of the plant, and evaluating the intoxication of the plants. Plant poisoning was also evaluated in the second experiment, along with crop production. No changes in the dry matter and plant poisoning were observed after the analyses performed in the controlled environment, showing that the cabbage presented tolerance to the applied herbicides. On the other hand, results from the experiments performed in the field showed that herbicide 2,4-D poisoned the cabbage causing reductions in production. Dicamba did not cause any damage in the initial phase of cultivation to this crop, with no reductions in its production. These results indicated the potential use of this herbicide in cabbage cultivation. It can be concluded from this study that the cultivar Astrus Plus is tolerant to dicamba. Under controlled conditions, 2,4-D does not cause toxicity to this cultivar, different from its effect when used in the field, where this herbicide can kill the cabbage plants.
{"title":"Tolerance of Cabbage Crop to Auxin Herbicides","authors":"A.L.V. Nascimento, Gustavo A. M. Pereira, L. F. Pucci, D. P. Alves, C. A. Gomes, M. R. Reis","doi":"10.1590/s0100-83582020380100017","DOIUrl":"https://doi.org/10.1590/s0100-83582020380100017","url":null,"abstract":"ABSTRACT: The presence of weeds in cabbage cultivation areas causes a reduction in the productivity and quality of the commercial product. Given the difficulties in management and the scarcity of registered products for weed control in cabbage cultivation, this study aimed to evaluate the tolerance of the cabbage cultivars Astrus Plus to the herbicides 2,4-D and dicamba. Two experiments were performed; one under controlled conditions and another conducted in the field. The efficacy of the herbicides on the initial growth of the crop was evaluated in the first experiment, measuring the dry matter of the aerial part, the root of the plant, and evaluating the intoxication of the plants. Plant poisoning was also evaluated in the second experiment, along with crop production. No changes in the dry matter and plant poisoning were observed after the analyses performed in the controlled environment, showing that the cabbage presented tolerance to the applied herbicides. On the other hand, results from the experiments performed in the field showed that herbicide 2,4-D poisoned the cabbage causing reductions in production. Dicamba did not cause any damage in the initial phase of cultivation to this crop, with no reductions in its production. These results indicated the potential use of this herbicide in cabbage cultivation. It can be concluded from this study that the cultivar Astrus Plus is tolerant to dicamba. Under controlled conditions, 2,4-D does not cause toxicity to this cultivar, different from its effect when used in the field, where this herbicide can kill the cabbage plants.","PeriodicalId":20102,"journal":{"name":"Planta Daninha","volume":"66 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67277747","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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