Field study on weeds incidence in rapeseed (Brassica campestris L.).

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

Download Full-text

Ervas daninha em pastagens: uma abordagem fitossociológica nas áreas do Ceará

Agrarian ◽

10.30612/agrarian.v12i45.7048 ◽

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

Keyword(s):

Relative Frequency ◽

Similarity Index ◽

Cyperus Rotundus ◽

Weed Species ◽

Importance Value Index ◽

Importance Value ◽

Brachiaria Decumbens ◽

The One ◽

Absolute Dominance ◽

Nicandra Physalodes

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.

Download Full-text

Weed population dynamics in rice crops resulting from post-emergent herbicide applications

Revista Facultad Nacional de Agronomía Medellín ◽

10.15446/rfna.v70n1.61762 ◽

2017 ◽

Vol 70 (1) ◽

pp. 8035-8043

Author(s):

Javier Ramírez ◽

Verónica Hoyos ◽

Guido Plaza

Keyword(s):

Population Dynamics ◽

Community Structure ◽

Relative Frequency ◽

Importance Value Index ◽

Importance Value ◽

Weed Population ◽

Weed Communities ◽

Weed Population Dynamics ◽

Importance Index ◽

Before And After

Studies on weed population dynamics are based on observing and recording changes in weed communities in response to effects of disturbances in crop management. The present study aimed to evaluate weed population dynamics in rice crops in Tolima, Colombia, resulting from post-emergent herbicide applications. Sampling was carried out in 0.1% of the cultivated area, marking out a 1 ha area in each commercial lot. Samples were taken before and after post-emergent applications. Evaluated variables were frequency, density, and cover. The data were analyzed using the Importance Value Index (IVI). Results demonstrated that Echinochloa colona was the most important weed of all of the evaluated zones, before and after post-emergent herbicide applications. Other notable species included Digitaria ciliaris, Cyperus iria and Ischaemum rugosum. Relative frequency variable was the most influential on the importance index of the species. Furthermore, herbicide applications generated changes in the community structure in the evaluated zones and in each evaluation.

Download Full-text

Phytosociological Survey of Weeds in Carpet Grass in Distinct Periods of the Year

Planta Daninha ◽

10.1590/s0100-83582016340400009 ◽

2016 ◽

Vol 34 (4) ◽

pp. 691-700

Author(s):

C.D.G. MACIEL ◽

C.N.M. OLIVEIRA ◽

A.A.P. SILVA ◽

R.A.K. KARPINSKI ◽

E.O. HELVIG ◽

...

Keyword(s):

Low Temperature ◽

Relative Frequency ◽

Temperature Tolerance ◽

University Campus ◽

Weed Species ◽

Importance Value Index ◽

Importance Value ◽

Low Temperature Tolerance ◽

Weed Infestation ◽

High Diversity

ABSTRACT Lawn with grass classified as Axonopus compressus is very common in Brazil Southern region, where it normally presents an adequate low temperature tolerance and a high diversity of weed infestation. This work has aimed to conduct a phytosociological survey of weeds in lawn consisting of Axonopus compressus from CEDETEG/UNICENTRO University campus located in the Brazilian municipality of Guarapuava, in the state of Paraná, in different periods of 2013. One hundred eighty 0.50 x 0.50 m samples were collected in four months, from which parameters frequency, density, abundance, relative frequency, relative density, relative abundance and importance value index were calculated. In general, 24, 7, 17 and 14 weed species were identified, distributed in 23, 3, 8 and 6 families, respectively, in April, June, October and December. The largest number of weed species was identified in Asteraceae, Fabaceae and Cyperaceae families. The ones classified as the most important and with occurrence over all periods of year were Trifolium repens (Fabaceae), Soliva pterosperma (Asteraceae) and Oxalis corniculata (Oxalidaceae).

Download Full-text

Phytosociological Survey of Sugarcane Crop Weeds in Different Agroecological Areas in Tucumán Province, Argentina

Planta Daninha ◽

10.1590/s0100-83582019370100027 ◽

2019 ◽

Vol 37 ◽

Author(s):

D.C. CABRERA ◽

S. CHAILA ◽

M.T. SOBRERO ◽

A.E. VARELA

Keyword(s):

Cynodon Dactylon ◽

Diversity Index ◽

Similarity Index ◽

Cyperus Rotundus ◽

Group Method ◽

Panicum Maximum ◽

Importance Value Index ◽

Importance Value ◽

Species Diversity Index ◽

Pampean Plain

ABSTRACT: Weeds constitute the main constraint on the productivity of sugarcane agroecosystems in Argentina. This work aimed to analyze the floristic and phytosociological composition of sugarcane weed communities in different agroecological areas in Tucumán. Fifteen plots from each area were sampled 60 to 90 days after crop shooting, by throwing a 0.5 m x 0.5 m quadrat metallic frame six times in random directions in each of the plots. Species found within the frame were identified. Later, fresh and dry biomass weight were calculated per quadrat sample and species. Frequency, density, dominance, importance value index, Shannon-Wiener and Simpson species diversity index and Jaccard similarity index were calculated. The unweighted pair group method with arithmetic mean (UPGMA) was used to interpret similarity. Overall, 35 species were identified, 24 of which were dicotyledons and 11 monocotyledons. Eighteen of them were annual species, versus 17 which were perennial. Considering IVI, the most outstanding families were Poaceae, Cyperaceae, Euphorbiaceae, Amaranthaceae and Asteraceae. The results obtained in all the areas revealed the importance of the species Panicum maximum, Sorghum halepense, Cyperus rotundus, Cynodon dactylon and Euphorbia hyssopifolia. The areas with greater and less diversity were the Depressed Plain-Non-Saline Depressed Plain Subregion and the Subhumid-Humid Chaco-Pampean Plain, respectively. There was a 53% similarity between the Depressed Plain-Saline Depressed Plain and the Depressed Plain-Non-Saline Depressed Plain, and a 47% similarity between the Humid and Perhumid Foothills and the Subhumid-Humid Chaco-Pampean Plain. Hierarchical clustering and Jaccard index led to similar results.

Download Full-text

PHYTOSOCIOLOGICAL SURVEY OF WEEDS IN ERECT PROSTRATE COWPEA CULTIVARS

Planta Daninha ◽

10.1590/s0100-83582017350100031 ◽

2017 ◽

Vol 35 (0) ◽

Author(s):

P.S.C. BATISTA ◽

V.S. OLIVEIRA ◽

V.B. SOUZA ◽

A.J. CARVALHO ◽

I. ASPIAZÚ

Keyword(s):

Relative Density ◽

Similarity Index ◽

Minas Gerais ◽

Importance Value Index ◽

Importance Value ◽

Cowpea Cultivars ◽

Minas Gerais State ◽

Weed Infestation ◽

Amaranthus Spp ◽

Growing Conditions

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.

Download Full-text

DISTRIBUTION PATTERN OF WEEDS IN WHEAT CROP GROWN IN DISTRICT KHANEWAL, PUNJAB, PAKISTAN

JOURNAL OF WEED SCIENCE RESEARCH ◽

10.28941/pjwsr.v26i1.806 ◽

2020 ◽

Vol 27 (2) ◽

pp. 47-59 ◽

Cited By ~ 1

Author(s):

Muhammad Usman ◽

Ghulam Murtaza ◽

Allah Ditta ◽

Tamana Bakht ◽

Muhammad Asif ◽

...

Keyword(s):

Distribution Pattern ◽

Growth And Yield ◽

Survey Study ◽

Cereal Crops ◽

Wheat Crop ◽

Weed Species ◽

Importance Value Index ◽

Importance Value ◽

Factors Affecting ◽

Weed Infestation

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.

Download Full-text

Komposisi Jenis, Struktur Komunitas, dan Keanekaragaman Mangrove Asosiasi Langge Kabupaten Gorontalo Utara-Provinsi Gorontalo

Jurnal Ilmu Lingkungan ◽

10.14710/jil.17.1.181-188 ◽

2019 ◽

Vol 17 (1) ◽

pp. 181

Author(s):

Sukirman Rahim ◽

Dewi Wahyuni K Baderan

Keyword(s):

Community Structure ◽

Species Diversity ◽

Relative Density ◽

Relative Frequency ◽

Diversity Index ◽

Mangrove Forests ◽

Chromolaena Odorata ◽

Importance Value Index ◽

Importance Value ◽

Nypa Fruticans

Hutan mangrove Langge yang terdapat di Kecamatan Anggrek Kabupaten Gorontalo Utara memiliki keunikan dari pola zonasi dan keanekaragaman jenis. Hal ini yang menjadikan hutan mangrove di kawasan tersebut sebagai objek wisata tracking mangrove yang dikenal dengan nama “mangrove in love. Hutan mangrove memiliki berbagai fungsi ekologis yang sangat kompleks yakni sebagai daerah pemijahan (spawing ground), tempat asuhan (nursery ground), dan tempat mencari makan (feeding ground) biota laut yang beraneka jenis dan memiliki fungsi ekonomis diantaranya buah mangrove dapat diolah menjadi berbagai produk kue dan sumber pangan alternatif pengganti beras. Penelitian ini bertujuan untuk : 1) untuk mengetahui komposisi jenis mangrove asosiasi; 2) untuk mengetahui struktur komunitas dari hutan mangrove Langge; dan 3) nilai Indeks Keanekaragaman. Adapun metode yang digunakan dalam penelitian ini adalah metode jalur berpetak (kombinasi plot dan transek). Jumlah spesies yang ditemukan akan dilihat untuk menjadi dasar penentuan komposisi jenis. Untuk pengkuran struktur komunitas mangrove dengan melakukan perhitungan terhadap Kerapatan Relatif (KR) dan Frekuensi Relatif (FR). Selanjutnya data yang didapatkan ditabulasikan untuk memperoleh nilai Indeks Nilai Penting (INP). Perhitungan keanekaragaman jenis menggunakan rumus (Sannon-wienner). Hasil penelitian menemukan 12 spesies tumbuhan mangrove asosiasi yakni Acanthus spinosus, Chromolaena odorata, Crassocephalum sp, Calotropis gigantean, Ipomea pes-caprae, Ricinus communis Excoecaria agallocha, Scaevola taccada, Spinifex littoreus, Terminalia catappa, Derris trifoliate dan Nypa fruticans. Struktur komunitas menunjukkan Chromolaena odorata memiliki nilai INP sebesar 33,2%, Kerapatan Relatif sebesar 24,91%, dan Frekuensi Relatif sebesar 8,33%. Spesies dengan nilai INP terendah dimiliki oleh Nypa fruticans yaitu sebesar 9,14%, Kerapatan Relatif sebesar 0,81%, dan Frekuensi Relatif sebesar 8,33%. Nilai Indeks Keanekaragaman (H’) mangrove asosiasi sebesar 2,175 dan termasuk dalam kriteria tingkat keanekaragaman sedang. Data yang diperoleh ini dapat digunakan dalam pengelolaan hutan mangrove di Gorontalo Utara serta dapat menjadi database dalam usaha konservasi mangrove guna mengurangi efek pemanasan global.Langge mangrove forest located in the District of North Gorontalo District Orchid has a uniqueness of zoning patterns and keanekragaman types. This is what makes the mangrove forests in the region as a tourist attraction tracking mangrove known as the "mangrove in love. Mangrove forests have a variety of ecological functions is very complex which is a spawning area (spawing ground), point of care (nursery grounds), and foraging (feeding ground) various types of marine life and has the economic function of which pieces of mangrove can be processed into various products cake and alternative food sources instead of rice. This study aims to: 1) to determine the association of mangrove species composition; 2) to determine the community structure of mangrove forests Langge; and 3) the value of diversity index. The method used in this study is a terraced path method (combination of plots and transects). The composition of the types of views based on the number of species found. For sizing mangrove community structure by calculating the Relative Density (KR) and Relative Frequency (FR). Then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of twelve species of mangrove plants and the relative dominance (DR), then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of eight species of mangrove plants and the relative dominance (DR), then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of twelve species of mangrove plantsnamely Acanthus spinosus, Chromolaena odorata, Crassocephalum sp, Calotropis gigantean, Ipomea pes-caprae, Ricinus communis Excoecaria agallocha, Scaevola taccada, Spinifex littoreus, Terminalia catappa, Derris trifoliate dan Nypa fruticans. Community structure showed Chromolaena odorata has a value of IVI of 33,2%, amounting to 24,91% Relative Density and Relative Frequency of 8,33%. The species with the lowest IVI owned by Nypa fruticans that is equal to 9,14%, 0,81% Relative Density and Relative Frequency of 8,33%. Values Diversity Index (H ') at 2.175 and mangrove associates included in the criteria for a medium level of diversity. The data obtained can be used in the management of mangrove forests in North Gorontalo and can be a database of mangrove conservation efforts to reduce the effects of global warming.

Download Full-text

Vegetation Analysis of the Tagafura Protected Forest in the City of Tidore Islands

Agrikan Jurnal Agribisnis Perikanan ◽

10.29239/j.agrikan.13.2.426-434 ◽

2020 ◽

Vol 13 (2) ◽

pp. 426

Author(s):

Sabaria Niapele ◽

Tamrin Salim

Keyword(s):

Relative Frequency ◽

Water Cycle ◽

Research Result ◽

Vegetation Analysis ◽

Importance Value Index ◽

Importance Value ◽

Forest Park ◽

The Earth ◽

The Government ◽

The City

The existence of Forest park vegetation in Tagafura as the vegetation cover are important to be maintain and preserved, since it’s effective for the human live on the earth. The function of this forest park is to defend the field around the forest in several ways such as, the water cycle, avoid the flood, erosion scheming and the soil fruitfulness keeper. The Tagafura Forest Park has a lot of natural resource, but the structure and the composition of the field are not completely found yet. Based on the the statement above the Researcher are interested to conduct the research entitled “ VEGETATION ANALYSIS OF THE TAGAFURA FOREST PARK IN TIDORE ISLAND to know about the structure and the composition of the vegetation in the Forest park of Tagafura and be able to being as the government substance while made a decision about the Forest park. This research used purposive sampling with a combination of to track and double plot to placement the plot. The data then analyzing used the density and relative density formula, domination and relative domination formula, frequency and relative frequency formula and The Importance Value Index (INP). Based on the research result, the data was founded that the forest has 25 structures include 15 types of Seedlings, 10 type of Stakes, 13 type of poles and 12 types of tress. The domination of the composition type amount the growth based on the INP is (1). Augenia aromatic with the INP in Seedling are 45,49. INP for Stand are 18,05. INP for the are 23,67 and the INP for the trees are 132.08. (2). Myristica fragrans has the INP for the seedlings are 31.44. INP for Stand are 15.11. INP for the poles are 30.27 and the INP for the trees are 47.25. (3). Gnetum gnemo has the INP for the seedlings are 19,48. INP for Stand are 24.21. INP for the poles are 49.92 and the INP for the trees are 10.83. (4). Arenga Pinnata has the INP for the seedlings are 18,13. INP for Stand are 36.11. INP for the poles are 24.04 and the INP for the trees are 17.51. (5). Cinnamomum verum has the INP for the seedlings are 11.84. INP for Stand are 33.17. INP for the poles are 26.42 and the INP for the trees are 7.36.

Download Full-text

Weed Phytosociology in Cassava Cultivation in Two Periods in Southwestern Bahia, Brazil

Planta Daninha ◽

10.1590/s0100-83582019370100107 ◽

2019 ◽

Vol 37 ◽

Author(s):

C.J.N. PRATES ◽

A.E.S. VIANA ◽

A.D. CARDOSO ◽

A.R. SÃO JOSÉ ◽

B.A.R. VIANA ◽

...

Keyword(s):

Weed Control ◽

Relative Abundance ◽

Relative Frequency ◽

Control Method ◽

Similarity Index ◽

Sampling Area ◽

Importance Value Index ◽

Importance Value ◽

Important Species ◽

Metal Frame

ABSTRACT: Knowing the most important species in the weed community is necessary to decide the best weed control method to be used. Thus, a phytosociological survey was carried out on cassava cultivation areas located in five rural properties of Cândido Sales, BA, Brazil, one of the state’s largest cassava producers. Two collections were carried out in each property in February (summer) and August (winter) 2016. A square metal frame with 0.25 m2 was randomly placed in each area, zigzagging, and establishing a proportion of 25 castings per hectare, with a sampling area of 6.25 m2 in each area. Weeds were identified and quantified, and then phytosociological parameters of frequency, density, abundance, relative frequency, relative density, relative abundance, and importance value index were determined. The analysis of the similarity between populations of the areas and periods was determined by the Sorensen similarity index. A variation of weed community composition was observed between cassava and harvest periods, with a higher infestation in the summer. A similarity was observed between cassava cultivation areas.

Download Full-text

Weed Survey Associated in Tobacco (Nicotiana tabacum L.) in Bilatte Tobacco Farm, Ethiopia

Advance in Biological Research ◽

10.26855/abr.2020005 ◽

2020 ◽

Vol 1 (1) ◽

pp. 29-33

Author(s):

Daniel Abebe ◽

Mekonnen Tadesse

Keyword(s):

Relative Abundance ◽

Cynodon Dactylon ◽

Datura Stramonium ◽

Survey Method ◽

Cyperus Esculentus ◽

Weed Species ◽

Importance Value Index ◽

Importance Value ◽

Nicotiana Tabacum L ◽

Weed Survey

An in-field weed survey method was conducted to estimate the most frequently, density and abundance weed species present in Bilatte tobacco farm, Ethiopia during 2014 totally covered approximately 145 hectares. During study period a total number of 14 weed species belonging to 06 monocot and 08 dicot families were recorded out of 7 families of weed reported form study site. The most predominate was shown by monocot Poaceae having 4 weed species followed by dicot family Composite having 3 weeds. The families Cyperaceous, Solanaceae and Amaranthaceous each having 2 weeds, and the family Papaverceae represented by 1 weed. Based on % of frequency Cyperus esculentus (sedges) family Cyperaceous was 99.30. The data showed that Cynodon dactylon and Digitaria abyssinica belong to family Poaceae and Cyperus esculentus family Cyperaceous were the most abundant weed with a density of 35.9, 14 and 12 of plant m-2 respectively. Relative abundance values quantify the overall weed problem posed by specie Cyperus esculentus that had higher relative abundance was 98.97. The importance value index indicated that Cyperaceous and Poaceae families can be considered the great potential to cause reduce tobacco production. Whereas, Solanium nigrum and Datura stramonium were observed with least population density 0.00 and 1.03 plant m-2, least frequently 2.7 and 13.51 %, least relative weed abundance, 0.07 and 1.03 with importance value index 2.8 and 14.8 occurring weed respectively.

Download Full-text