scholarly journals PHYTOSOCIOLOGICAL SURVEY OF WEEDS IN ERECT PROSTRATE COWPEA CULTIVARS

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
P.S.C. BATISTA ◽  
V.S. OLIVEIRA ◽  
V.B. SOUZA ◽  
A.J. CARVALHO ◽  
I. ASPIAZÚ

ABSTRACT The goal of this study is to characterize the weed phytosociology in some major erect and prostrate cowpea cultivars in Brazil, in the Northern growing conditions of Minas Gerais state. The test was conducted in Janaúba, Minas Gerais state. The treatments consisted in five erect cultivars (BRS Guariba, BRS Tumucumaque, BRS Novaera, BRS Itaim and BRS Cauamé) and four prostrate ones (BRS Marataoã, BRS Pajeú, BRS Pujante and BRS Xiquexique). The plots were composed of four five meter rows, spaced 0.5 m apart, for erect cultivars and 1.0 m for the prostrated ones. Weed sampling was performed 50 days after sowing by standard Square Method. The species were identified and quantified, and then dried at 65 oC for 72 hours and weighed. The frequency, absolute and relative density and abundance, the importance value index (IVI) and the similarity index were evaluated. In the erect cultivars, the Amaranthaceae, Euphorbiaceae, Asteraceae and Convolvulaceae families stood out with higher IVI’s. In prostrate cultivars, the Amaranthaceae, Asteraceae and Malvaceae families stood out. Portulaca oleracea and Amaranthus spp. were the species with the highest IVI. The similarity index between erect and prostrate cultivars was 72%; nine of the 16 families occurred in both cultivars. BRS Tumucumaque, erect, and BRS Pujante, prostrate had lower weed infestation.

Nativa ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 528-535
Author(s):  
Marlon Lopes Lacerda ◽  
Dhanne Lucas Soares Silva ◽  
Ignacio Aspiazú ◽  
Abner José de Carvalho ◽  
Simônica Maria de Oliveira ◽  
...  

O presente trabalho teve como objetivo caracterizar a dinâmica da comunidade infestante de plantas daninhas em cultivo do feijão-caupi no semiárido mineiro. Os tratamentos consistiram na coleta das plantas daninhas aos 7, 14, 21, 28, 35, 42, 49, 56, 63 dias após a emergência (DAE), posteriormente foi feito o controle da comunidade infestante por capina mecânica. A coleta de plantas daninhas foi feita pelo método padrão do quadrado inventário, lançado aleatoriamente na área útil de cada parcela, recolhendo todas as plantas. Foram determinados o número de indivíduos por espécie em cada parcela e o número total por coleta. Após a identificação e contagem das espécies, foi realizado o cálculo das variáveis fitossociológicas: Frequência, Densidade, Abundância, Frequência relativa, Densidade relativa, Abundância relativa, Dominância relativa, Índice de valor de importância (IVI), Índice de valor de cobertura (IVC) e Índice de similaridade (IS). As espécies Portulaca oleracea, Amaranthus viridis e Sorghum bicolor apresentaram maiores valores de IVI. Foi possível afirmar que é alta a similaridade florística das espécies de plantas daninhas que ocorreram durante o ciclo do feijão-caupi. Quanto ao Índice de valor de Cobertura (IVC), destacaram-se as espécies Portulaca oleracea, Sorghum bicolor e Senna obustifolia. Palavras-chave: comunidade infestante; Vigna ungiculata; levantamento fitossociológico.   Phytosociology of weeds in cultivation of cowpea in the semi-arid region of Minas Gerais   ABSTRACT: The present work aimed to characterize the dynamics of the weed community in cultivation of cowpea in the semi-arid region of Minas Gerais. The treatments consisted of collecting the weeds 7, 14, 21, 28, 35, 42, 49, 56, 63 days after emergence (DAE); following each collection, the weed community was controlled by mechanical weeding. The collections were carried out using the standard method of the inventory square, randomly launched in the useful area of each plot, collecting all the plants. The number of individuals per species in each plot and the total number per collect were determined. After identifying and counting the species, the phytosociological variables were calculated: Frequency, Density, Abundance, Relative frequency, Relative density, Relative abundance, Relative dominance, Importance value index (IVI), Coverage value index (CVI) and Similarity Index (SI). The species Portulaca oleracea, Amaranthus viridis and Sorghum bicolor presented the largest IVI. It was possible to affirm that the floristic similarity of the weed species that occurred during the cowpea cycle is high.  The species Portulaca oleracea, Sorghum bicolor and Senna obustifolia presented the highest CVI values. Keywords: infestant comunnity; Vigna ungiculata; phytosociological survey.


2019 ◽  
Vol 37 ◽  
Author(s):  
P.H.S. MENEZES ◽  
J.A.A. ALBUQUERQUE ◽  
J.O. SMIDERLE ◽  
R.D. MEDEIROS ◽  
J.M.A. ALVES ◽  
...  

ABSTRACT: Weeds from soils submitted to different tillage managements were identified in two consecutive years of soybean cultivation in the Cerrado of Roraima. The study was carried out in three areas: native area (NA), mechanically mowed native area (MA), and limed area (LA). A descriptive analysis of the phytosociological parameters relative density (Drr), relative frequency (Frr), relative dominance (Dor), importance value index (IVI), and index of relative importance (IRI) was performed to interpret the results. The weed similarity index (SI) was also calculated in the assessed areas. The highest relative frequencies were observed for Trachypogon plumosus (40.92%), Bulbostylis capillaris (18.52%), and Spermacoce capitata (18.33%) in the native area and T. plumosus (24.69%), Cyperus flavus (24.69%), and S. capitata (18.52%) in the mowed area. Among the species collected in the areas, the botanical families Poaceae, Cyperaceae, Fabaceae, and Rubiaceae are the most representative. The used managements contribute to the emergence of new species of spontaneous plants and weeds in the Cerrado of Roraima.


2016 ◽  
Vol 34 (3) ◽  
pp. 497-507 ◽  
Author(s):  
P.S.C. BATISTA ◽  
V.S. OLIVEIRA ◽  
A.M. CAXITO ◽  
A.J. CARVALHO ◽  
I. ASPIAZÚ

ABSTRACT The objective of this paper was to characterize the phytosociology of weeds in function of different types of growth of common bean cultivars in the North of Minas Gerais. The study was conducted in the experimental area, located in the municipality of Janaúba, MG. The treatments consisted of eight commercial cultivars of common beans with different types of growth. The design was done in randomized blocks, with three replications. The soil preparation was conventional and the planting was done in June, with manual seeders, with a 0.5 m spacing between rows. The phytosociological survey was performed in two phases of bean cultivation, in stages V3 and R8. The method used was the square inventory one, with a 0.25 m2 frame, randomly released once in each plot. Samples of each square were identified and quantified by family, genus and species, and the sampled plants were collected with their complete structure. Next, the material was sent to a drying greenhouse with forced air circulation at 65 oC for 72 hours, for drying and determination of weight of dry matter. We also estimated the Relative Frequency, Relative Density and Relative Abundance to determine the importance value index and similarity index. At the V3 stage, the species Sorghum halepense, Brachiaria plantaginea and Boerhavia diffusa had higher importance value indexes. At the R8 stage, the Amaranthus viridis specie showed higher importance value index and dry matter. In more prostrate cultivars, the weeds present lower importance value indexes at the R8 stage.


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
R.C. DIAS ◽  
M.V. SANTOS ◽  
E.A. FERREIRA ◽  
T.G.S BRAZ ◽  
L.V. FIGUEIREDO ◽  
...  

ABSTRACT: In pastures, the incidence of weeds reduces the productivity and quality of forage. The identification of the weed species in pastures is fundamental to choose the renewal method. Thus, the objective of this work was to perform phytosociology before and after the renewal of a Brachiaria decumbens pasture, with the implantation of agrosilvopastoral systems. Eighteen different crop arrangements for pasture renewal were evaluated. The renewal systems were by eucalyptus integration (at 12 x 2 m or 12 x 3 m spacings) with maize, Brachiaria brizantha cv. Marandu (palisade grass) and/or Macrotyloma axillare (perennial horsegram), or monoculture and intercropping of palisade grass and perennial horsegram, as well as the evaluation of the application or not of the herbicide bentazon, at the recommended dose for maize crops (0.72 kg ha-1). Relative frequency, relative density, relative abundance, relative dominance, coverage value index, importance value index, dry matter and similarity index were evaluated. In the first survey, before the pasture renewal, 23 plant species were identified. After the implantation of agrosilvopastoral systems, the species Sida cordifolia, Lantana camara and B. decumbens were the only occurring ones before and after the renewal of the pasture with agrosilvopastoral systems. The use of palisade grass and the application of the herbicide were efficient in controlling weeds. In systems that contained palisade grass and perennial horsegram, the latter was not found in the survey conducted one year after the implantation.


2017 ◽  
Vol 35 (0) ◽  
Author(s):  
J.A.A. ALBUQUERQUE ◽  
T.S. SANTOS ◽  
T.S. CASTRO ◽  
V.F. MELO ◽  
P.R.R. ROCHA

ABSTRACT The goal of this study was to evaluate the occurrence of weeds after soybean harvest in rotational systems of no-till and conventional tillage in the savannah of Roraima, Brazil. Two simultaneous experiments were conducted in adjacent areas, the first one with no-till soil management system and the second one with the conventional system, with crop rotations for five agricultural years: pearlmillet (2007/2008), soybean (2008/2009), maize (2009/2010), cowpea with maize (2010/2011), soybean (2011/2012) and maize (2012/2013). The used experimental design was the randomized block one with 28 plots, sized 3 x 15 m (45 m2) distributed in 4 blocks. In May 2010, the combined sowing of cowpea and maize was performed, and later, during the same month of 2011 soybean was sown. Thirty days after harvesting, weeds were collected. The botanical classification of species was performed by classes, families, scientific and popular names, as well as comparisons with specialized bibliographies. The evaluated phyto-sociological parameters were: relative frequency (FRR), relative density (DRR), dominance (Do), importance value index (IVI), Sorensen’s similarity index (SI), numbers of individuals (ha-1) and dry mass (%). Among the 37 species found in both planting systems, 60% belonged to the Liliopsida class; Fabaceae and Malvaceae stood out. However, Poaceae, belonging to the Magnoliopsida class, had the highest number of species in both systems. Most weed species were common in both systems.


2019 ◽  
Vol 26 ◽  
pp. 1-6
Author(s):  
MT Akhter ◽  
PB Kundu ◽  
NK Paul

A survey was conducted to highlight the weed flora infesting rapeseed in the experimental field of Rajshahi University. Frequency (F), density (D), abundance (A), relative frequency (RF), relative density (RD), relative abundance (RA) and importance value index (IVI %) of weeds were calculated in rapeseed field. The objective of the study was to study the weeds and their quantitative characters. Weed infestation was studied in three rapeseed varieties (BARI Sharisha 14, BINA Sharisha 5 and 6). The weed population was studied using quadrat. The species which had 100% frequency values were Cyperus rotundus, Cynodon dactylon, Ammania baccifera, Echinochloa crusgalli and Leucas lavendulifolia. Other species had 50% or less than 50% frequency values. The highest frequency, density, abundance and importance value index were exhibited by Cyperus rotundus. J. bio-sci. 26: 01-06, 2018


Agrarian ◽  
2019 ◽  
Vol 12 (45) ◽  
pp. 279-285
Author(s):  
Josefa Maria Francieli da Silva ◽  
Hercules Gustavo Santos Sarmento ◽  
Hellen Thayse Nascimento Araújo ◽  
Alexandre Bosco de Oliveira ◽  
Lamartine Soares Cardoso de Oliveira

The aim of this study was to study the phytosociology of weed species in areas of pasture cultivated with Brachiaria decumbens and Cynodon sp. (Tifton 85), in Ceará State, Brazil. The square inventory methodology was used in order to assess the weed community. Weed samples were quantified and classified by family, genus and species, using books and classification keys. The classification and quantification data of species allowed to calculate the following phytosociological variables: frequency (F), relative frequency (Fr), density (D), relative density (Dr), absolute dominance (DoA), relative dominance (DoR), importance value index (IVI), and similarity index (IS). The Amaranthaceae family was the one with the greatest intensity of species in both areas, represented mainly by Alternanthera tenera colla and Amaranthus viridis. In the area cultivated with B. decumbens, Cyperus rotundus presented higher results for frequency, density and abundance. In the Tifton 85 area, Nicandra physalodes presented higher values of density and abundance. The similarity of weed populations in pasture areas was 42.11%, with four species common to both areas.


2018 ◽  
Vol 20 (1) ◽  
pp. 259-266
Author(s):  
FAIZAL KASIM ◽  
MIFTAHUL KHAIR KADIM ◽  
SITTI NURSINAR ◽  
ZULKIFLI KARIM ◽  
ALDIN LAMALANGO

Kasim F, Kadim MK, Nursinar S, Karim Z, Lamalango A. 2019. Comparison of true mangrove stands in Dudepo and Ponelo Islands, North Gorontalo District, Indonesia. Biodiversitas 20: 259-266. This study aimed to investigate and compare the current status of mangrove areas, as well as the composition and species diversity of mangrove stands in both regions of Dudepo and Ponelo Islands. The results showed that the mangrove areas calculated using the segmentation method in classifying image of Landsat-8 OLI (acquisition on September 2017) were 279.46 ha (Dudepo Island) and 113.35 ha (Ponelo Island) respectively. A total of 13 species of true mangrove were recorded from both islands, using survey method from 9 transect lines (TL), with a distance ranging from 40 to 210 meters (1-6 quadrats) per transect. The mean densities of trees were 2133 ± 329.78 ha-1 (Dudepo Island) and 2111 ± 234.28 ha-1 (Ponelo Island), while those of saplings and seedlings were 58 ± 13.48 ha-1 and 1425 ± 113.96 ha-1 (Dudepo Island), and 79 ± 14.51 ha-1 and 2963 ± 443.22 ha-1 (Ponelo Island). The mean diameter and basal area were 19.73 ± 10.65 cm and 84.22 ± 67.67 m2ha-1 (Dudepo Island), 17.04 ± 1.46 cm and 60.07 ± 15.12 m2ha-1 (Ponelo Island), respectively. The Importance Value Index (IVI) ranged between 3.97-114.87 (Dudepo Island) and 6.04-82.18 (Ponelo Island). The dominant and codominant species based on IVI in both islands were Rhizophora apiculata Blume and R. stylosa Griff. The indexes of diversity, richness, and evenness of mangrove species in both islands were 0.34-1.70, 0.48-1.18, 0.47-0.94 (trees), 0.00-1.10, 0.00-1.82, 0.00-1.00 (saplings), and 0.00.-1.48, 0.00-1.44, 0.72-1.00 (seedlings), respectively. The Bray-Curtis similarity index between Dudepo and Ponelo Islands, based on the overall values of community attributes, was 0.75.


Nativa ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 427-435
Author(s):  
Davair Lopes Teixeira Junior ◽  
José Maria Arcanjo Alves ◽  
José Anchieta Alves Albuquerque ◽  
Paulo Roberto Ribeiro Rocha ◽  
Thais Santiago Castro ◽  
...  

Sistemas de manejos das plantas daninhas, utilizando diferentes estratégias de controle, podem alterar a dinâmica populacional das plantas e favorecer o controle de algumas espécies. Objetivou-se com esse trabalho avaliar a ocorrência de plantas daninhas antes e após cultivo de feijão-caupi, em plantio direto, sob quatro formas de manejo da vegetação natural (sem roçada, com roçada, uso de fogo e dessecação com glyphosate) em área da savana Amazônica no estado de Roraima. As avaliações foram realizadas mediante a aplicação do método do quadrado inventário. As plantas daninhas situadas nas áreas amostradas foram cortadas rente ao solo, identificadas e quantificadas. Os parâmetros fitossociológicos analisados foram: frequência relativa, densidade relativa, abundância relativa, índice de valor de importância e índice de similaridade. As principais famílias identificadas foram Cyperaceae, Poaceae e Fabaceae. As formas de manejo da vegetação natural da savana de Roraima para o cultivo do feijão-caupi favoreceram a emergência de 10 espécies de um total de 29. O manejo com o herbicida glyphosate proporcionou o desenvolvimento das espécies Digitaria insularis e Hynchelitrum repens e o controle de 12 espécies, entre elas o Trachypogon plumosus, importante forrageira da região em estudo. O manejo da vegetação natural com o fogo favoreceu o surgimento da espécie Desmodium tortuosum. O manejo com glyphosate promoveu alterações na comunidade infestante de plantas daninhas, nesse foi observado os menores índices de similaridade entre os sistemas de manejo avaliados.Palavras-chave: fitossociologia; Vigna unguiculata; vegetação natural; manejo com fogo. OCCURRENCE OF WEEDS IN COWPEA CULTURE UNDER FOUR HANDLES IN THE WESTERN AMAZON ABSTRACT: Weed management systems, using different control strategies, can change the population dynamics of plants and favor the control of some species.The objective of this work was to evaluate the occurrence of weeds before and after cowpea cultivation under no-tillage under four forms of natural vegetation management (no-till, no-till, use of fire and glyphosate desiccation) in an area of savannah of Roraima. Evaluations were performed by applying the inventory square method. Weeds located in the sampled areas were sectioned close to the ground, identified and quantified. The phytosociological parameters analyzed were: relative frequency, relative density, relative abundance, importance value index and similarity index. The main families identified were Cyperaceae, Poaceae and Fabaceae. The management of the natural vegetation of the Roraima savanna for cowpea cultivation favored the emergence of 10 species out of 29. Management with the herbicide glyphosate provided the appearance of the species Digitaria insularis and Hynchelitrum repens and the control of 12 species, including the Trachypogon plumosus, an important savanna forage. The management of natural vegetation with fire favored the emergence of the species Desmodium tortuosum. Glyphosate management caused changes in the weed community, which showed the lowest similarity indexes between the evaluated management systems.Keywords: phytosociology; Vigna unguiculata; natural vegetation; fire management.


2020 ◽  
Vol 27 (2) ◽  
pp. 47-59 ◽  
Author(s):  
Muhammad Usman ◽  
Ghulam Murtaza ◽  
Allah Ditta ◽  
Tamana Bakht ◽  
Muhammad Asif ◽  
...  

Weed infestation is among the main biotic factors affecting growth and yield of various crops. This issue is more drastic for cereal crops like wheat which is the staple food crop of over 2.5 billion population of the world. One the control strategy is the investigated the distribution pattern of weeds under field conditions. In this regard, a survey study was conducted to investigate the distribution pattern of weed species in wheat crop during 2016-18 in district Khanewal, Punjab Pakistan. Thirty-six weed species distributed among fifteen different families collected from the study area. Family Poaceae was dominant with 10 species while family Asteraceae was the second most dominant family with four weed species. Cynadon dactylon was the most frequently found specie with frequency value 79.1% while Paspalum distichum had the highest importance value index (6.96) among the weeds of the study area.


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