scholarly journals Diversity of Weed Species in Farms Kisii Central Sub-County, Western Kenya

2019 ◽  
Vol 6 ◽  
pp. 11-19
Author(s):  
Charles N. Nyamwamu ◽  
Rebecca Karanja ◽  
Peter Mwangi
Keyword(s):  
Species Diversity ◽  
Cynodon Dactylon ◽  
Shannon Index ◽  
Line Transect ◽  
Cyperus Esculentus ◽  
Weed Species ◽  
Bidens Pilosa ◽  
Importance Value ◽  
Western Kenya ◽  
Equal Distance

This study sought to determine species diversity and Importance Values (IV) of weeds in farms in Kisii Central Sub County, Western Kenya. Eight administrative sub-locations were randomly selected. Ten farms were selected at equal distance along transect laid across each sub-location. Quadrant and a line transect laid across each farm were used to collect weed species. Five rectangular quadrants of 0.5x2m were established in each farm and individuals of each weed species identified and counted. Importance value (IV) for each weed species was computed from density, frequency and abundance. Diversity was computed by Shannon index (H’). Twenty four weed species from 22 genera in 10 families were recorded, Family Asteraceae had the highest number of species (6), followed by Solanaceae and Poaceae with 4 and 3 species respectively. The dominant weed species were Galinsoga parviflora(IV=241.6%), Pennisetum clandestinum(IV=215.8.7%),Bidens pilosa(IV=196.7%), Cynodon dactylon (IV=192.4%), Digitaria scalarum(IV=180.8%) and Cyperus esculentus(172.0%). Weed species diversity was higher (H'=2.81).

scholarly journals Distribution and Impact of Parthenium (Parthenium hysterophorus L.) on Weed Species Diversity in Maize Fields in Western Gojjam Zone, Amhara National Regional State, Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Dinberu Million ◽  
Lisanework Nigatu ◽  
Zelalem Bekeko ◽  
Hirpa Legesse
Keyword(s):  
Species Diversity ◽  
Parthenium Hysterophorus ◽  
Infestation Level ◽  
Weed Species ◽  
Ageratum Conyzoides ◽  
Bidens Pilosa ◽  
Importance Value ◽  
Amaranthus Hybridus ◽  
West Gojjam ◽  
West Gojjam Zone

An investigative weed flora survey was conducted in parthenium-infested maize fields in West Gojjam Zone in 2019/2020. The objective was to investigate the distribution and impact of parthenium on species diversity. A survey was conducted on 90 fields using 2 m × 2 m (4 m2) quadrats (totally 270). A total of 110 weed species belonging to 27 families were identified out of these families. Asteraceae with 26 species (23.36%) and Poaceae with 18 species (16.36%) were abundant. The highest importance value (IV) was recorded by Ageratum conyzoides, Amaranthus hybridus, and Bidens pilosa, with 28.05, 19.18, and 13.16%, respectively, in no parthenium infestation level. The highest IV of 27.08, 17.71, and 16.44%, respectively, was shown by Ageratum conyzoides, Bidens pilosa, and Galinsoga parviflora with 27.08, 17.71, and 16.44%, respectively, in very low parthenium infestation level. Ageratum conyzoides (29.38%), Bidens pilosa (24.10%), and Parthenium hysterophorus (22.68%) had the highest IV in low parthenium infestation level. Parthenium hysterophorus (91.32%), Ageratum conyzoides (17.19%), and Echinochloa colona (16.34%) had high IV in moderate parthenium infestation level. It is concluded that Ageratum conyzoides, Bidens pilosa, Echinochloa colona, and Galinsoga parviflora were competitive over parthenium based on importance value, and this indicates to suggest parthenium as a biological management option.

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

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.

scholarly journals Relation between Soil Weed Seedbank and Weed Management Practises and Diversity in Farms in Kisii Central Sub County, Nyanza

2020 ◽  
Vol 10 ◽  
pp. 1-14
Author(s):  
Charles N. Nyamwamu ◽  
Rebecca Karanja ◽  
Peter Mwangi
Keyword(s):  
Seed Bank ◽  
Weed Management ◽  
Management Practices ◽  
Soil Seed Bank ◽  
Shannon Index ◽  
Weed Seed ◽  
Weed Species ◽  
Western Kenya ◽  
Weed Diversity ◽  
Hand Weeding

This study sought to determine the relation between soil weed seed bank and weed management practices and diversity in farms in Kisii Central Sub County, Western Kenya. Eight administrative sub-locations were randomly selected. Ten farms were selected at equal distance along transect laid across each sub-location. Weed soil seed bank was assessed from soil samples collected from each of the farms; a sub-sample was taken from a composite sample of ten soil cores of 5cm diameter and 15cm deep and placed in germination trays in a greenhouse. Weed diversity in soil weed seedbank was calculated using the Shannon index (H’). Twelve weed species from 12 genera of nine families were recorded. Diversity of the weed species in soil weed seed bank was (H'=1.48). Weed management practises significantly affected weed species soil weed seedbank reserves. Use of inefficient and ineffective hand-weeding techniques resulted in high weed species diversity and abundance.

scholarly journals Floristic diversity of the soil weed seedbank in boro rice fields: in situ and ex situ evaluation

2018 ◽  
Vol 16 (3) ◽  
pp. 396-402
Author(s):  
Fahmida Akter ◽  
Mahfuza Begum ◽  
Md. Abdus Salam
Keyword(s):  
Shannon Index ◽  
Ex Situ ◽  
Floristic Diversity ◽  
Weed Species ◽  
Importance Value ◽  
Emergence Period ◽  
Research Fields ◽  
Weed Survey ◽  
Boro Rice

This study was conducted at the research fields of Agronomy Field Laboratory and in the net house of Department of Agronomy, Bangladesh Agricultural University, Mymensingh. The objective of this study was to compare the in situ and ex situ floristic diversity of soil weed seedbank in boro rice. The soil weed seedbank status was observed through weed survey at research fields and seed germination method in the net house. Five fields were selected randomly with four replications. Soil samples were collected to a depth up to 15 cm and placed in plastic pots in the net house. Weed seedlings that emerged were identified, counted and removed at 30 day intervals throughout the four months emergence period. At the same time, weed survey was done using a 0.25 m–2 quadrate. Diversity was computed by the Shannon index (H’). Under in situ condition, 31 weed species belonging to 15 families germinated and 33 weed species belonging to 17 families germinated under ex situ condition. The family Cyperaceae had the highest species richness under both in situ and ex situ conditions. The five most dominant weed species under in situ condition based on importance value were Eleocharis atroperpurea > Cyperus difformis > Echinochloa crusgalli > Monochoria vaginalis > Lindernia antipoda whereas, under ex situ condition, two new weed species, Fimbristylis miliacea and Echinochloa colonum were observed in the dominant list instead of Monochoria vaginalis and Lindernia antipoda having slightly different rank and order. The ex situ density was 2721 plants m–2, approximately four times higher than the 700 plants m–2 observed under in situ situation and similarly ex situ condition had higher Shannon Index (H’) value (H’=2.412) indicating greater diversity than in situ (H’=2.211) condition. The information obtained from the study would help determine the infestation potential of identified species, which could lead to improved management strategies. J. Bangladesh Agril. Univ. 16(3): 396–402, December 2018

scholarly journals Analisis Vegetasi Pada Habitat Gajah Sumatera Di Suaka Margasatwa Padang Sugihan Provinsi Sumatera Selatan

2013 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Agnes Indra Mahanani ◽  
Ign Budi Hendrarto ◽  
Tri Retnaningsih Soeprobowati
Keyword(s):  
Species Diversity ◽  
Cynodon Dactylon ◽  
Natural Habitat ◽  
Index Formula ◽  
Natural Food ◽  
Importance Value Index ◽  
Importance Value ◽  
Melaleuca Cajuputi ◽  
Panicum Repens ◽  
Wildlife Reserve

Padang Sugihan Wildlife Reserve covering 86,932 hectares is the natural habitat of elephants in South Sumatra, both wild and managed elephants at Elephant Training Center, Sub Padang Sugihan. This area was used to be production forest. To support life of wild elephants, the vegetation quantity and diversity of vegetation types of feed must be known. This study aimed to analyze the vegetation feed elephants in Padang Sugihan Wildlife Reserve. The method used sampling plots with a size of 1m x 1m and 5m x 5m in five study sites. Data were analyzed using analysis of vegetation to get the importance value index. Species diversity was calculated using the Shannon Wienner Index formula. It was also calculated the value of uniformity of plant based on Simpson formula. The results of importance value index showed that location I was dominated by Echinochloa colonum (L.) Link (76.55%), location II Panicum astagninum R (132.48%), location III  Panicum repens L (107.14%), location IV Axonopus caompressus ( 79.48%), location of V Panicum repens L and Cynodon dactylon (L.) Pers. (21.28%), location VI Melaleuca cajuputi (80.77%), and location VII Melaleuca cajuputi (84.08%). The value of the highest species diversity in the location of V at 2.53. The lowest value was in location II at 0.66. The highest uniformity index was 0.92. While the lowest value was 0.37 in the location II. Based on the above results it is necessary to enrich the vegetation species of elephant grass and natural food, especially at locations II and III.   Keyword: Padang Sugihan Wildlife Reserve, vegetation analysis, Elephas maximus sumateranus Temminck  

scholarly journals Short Communication: Analysis of weed vegetation in immature and mature oil palm plantations

2019 ◽  
Vol 20 (11) ◽  
Author(s):  
Halus Satriawan ◽  
ZAHRUL FUADY
Keyword(s):  
Species Diversity ◽  
Relative Density ◽  
Palm Oil ◽  
Oil Palm ◽  
Cynodon Dactylon ◽  
Diversity Index ◽  
Communication Analysis ◽  
Importance Value ◽  
Species Diversity Index ◽  
Local Climate

Abstract. Satriawan H, Fuady Z. 2019. Analysis of weed vegetation in immature and mature oil palm plantations. Biodiversitas 20: 3292-3298. The species of weeds which grow and dominate in palm oil areas depend on location, local climate, and the light received. This research aimed to determine the diversity of weeds in the planting of palm oil with a different age grown in 2012, 2013, 2014 and 2016. The sample slots measured uniformly at 1 m x 1 m totaling 25 plots. Vegetation analysis was conducted to the density (D), relative density (RD), frequency (F), relative frequency (RF), important value index (IVI), Summed Dominance Ratio (SDR), and Species Diversity Index (H’). Weed composition includes 21 families with 36 species, with the total number of each individual during the year of palm oil planting was 3540, 3148, 3731, and 2910. The relative density value of the highest weeds in the planting year group in 2012 and 2013 were Asystasia intrusa (20.22% and 21.05%), in 2014 were Eleusine indica (23.93%) and 2016 were Cynodon dactylon with 24. 49%. The importance value of weeds in four groups in planting year of oil palm was also in line with the relative density value. These were A. intrusa in 2012 and 2013, amounting to 27.41 and 27.95 and in 2014 and 2016, totaling to 23.72 and 37.64 was E. indica and C. dactylon. The value of the highest species diversity of 6.85 was found in the year 2014, followed by 2012 with 5.88.

Herbicide Residues and Weed Species Shifts on Modified-Soil Field Plots

Weed Science ◽  
1974 ◽  
Vol 22 (5) ◽  
pp. 427-433 ◽  
Author(s):  
J. B. Weber ◽  
J. A. Best ◽  
W. W. Witt
Keyword(s):  
Organic Matter ◽  
Chemical Analysis ◽  
Cynodon Dactylon ◽  
First Year ◽  
Cyperus Esculentus ◽  
Weed Species ◽  
Yellow Nutsedge ◽  
Dactyloctenium Aegyptium ◽  
Field Plots ◽  
Large Crabgrass

A Shubata soil was modified by the addition of organic matter or montmorillonite clay. Three annual applications of fluometuron [1,1-dimethyl-3-(α,α,α-trifluro-m-tolyl)urea], prometryne [2,4-bis(isopropylamino)-6-(methylthio)-s-triazine], and trifluralin (α,α,α-trifluro-2,6-dinitro-N,N-dipropyl-p-toluidine) were made and soil samples analyzed at the end of the third year. Less than 0.05 ppm prometryne was found in the subsoils. Prometryne present (by chemical analysis) in the surface soils ranged from 2% (of that originally applied) in the soil without additives to 20% in the soils modified with organic matter and clay. Approximately 12% of the prometryne present in the soil modified with organic matter and 32% of that in the soil modified with clay was detectable by bioassay. Trifluralin concentration (by chemical analysis) ranged from 2% in the soil without additives and soil modified with clay to 11% in the soil modified with organic matter. Approximately 100% of the trifluralin in soil without additives and soil modified with clay was detectable by bioassay while only 15% of that present in soil modified with organic matter was biologically detectable. Fluometuron was presented in the soils in amounts ranging from 0.6 to 1.9% of that applied. Prometryne and fluometuron greatly decreased the large crabgrass [Digitaria sanguinalis(L.) Scop.] population and increased the population of yellow nutsedge (Cyperus esculentusL.) and crowfootgrass [Dactyloctenium aegyptium(L.) Richter]. Trifluralin greatly decreased large crabgrass and crowfootgrass populations, but the plots became completely infested with yellow nutsedge. Horseweed [Conyza canadensis(L.) Cronq.] became the overall dominant species the first year after the field was taken out of production. Yellow nutsedge, bermudagrass [Cynodon dactylon(L.) Pers.], and other grasses were also prevalent.

Struktur Makroalga Pada Ekosistem Lamun Di Kecamatan Tabukan Selatan, Kabupaten Kepulauan Sangihe, Sulawesi Utara (Structure of Macroalgae in Seagrass Ecosystems at South Tabukan District, Sangihe Islands Regency, North Sulawesi

2019 ◽  
Vol 9 (1) ◽  
pp. 44
Author(s):  
Irawaty Mertosono ◽  
Ratna Siahaan ◽  
Pience Maabuat
Keyword(s):  
Sampling Technique ◽  
Marine Macroalgae ◽  
Line Transect ◽  
Land Conversion ◽  
Importance Value Index ◽  
Importance Value ◽  
North Sulawesi ◽  
Sea Transportation ◽  
Seagrass Ecosystems ◽  
Biodiversity Decline

Struktur Makroalga Pada Ekosistem Lamun Di Kecamatan Tabukan Selatan, Kabupaten Kepulauan Sangihe, Sulawesi Utara(Structure of Macroalgae in Seagrass Ecosystems at South TabukanDistrict, Sangihe Islands Regency, North Sulawesi) Irawaty A. Mertosono1), Ratna Siahaan1*) Pience V. Maabuat1)1)Jurusan Biologi, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Sam Ratulangi, Manado 95115*Email korespondensi:[email protected] Diterima  15 Februari 2019, diterima untuk dipublikasi 28 Februari  2019 Abstrak Makroalga laut merupakan tumbuhan laut yang tidak memiliki akar, batang, maupun daun sejati. Kegiatan manusia berupa pemanfaatan makroalga, konversi lahan, dan transportasi laut dapat menjadi penyebab penurunan biodiversitas makroalga. Tujuan penelitian ini adalah untuk menganalisis struktur dan distribusi makroalga pada ekosistem lamun di Kecamatan Tabukan Selatan, Kabupaten Kepulauan Sangihe, Sulawesi Utara. Lokasi penelitian di tiga stasiun penelitian yaitu Pantai Karurung - Desa Salurang, Pantai Palareng - Desa Palareng dan Pantai Galoghong – Desa Batuwingkung. Penelitian dilakukan pada November-Desember 2018 dengan pengambilan sampel menggunakan metode garis transek (line transect) dengan teknik pencuplikan kuadrat. Makroalga yang ditemukan sebanyak 36 spesies yang terdiri atas 25 spesies Divisi Chlorophyta, sembilan (9) spesies Divisi Rhodophyta dan dua (2) spesies Divisi Phaeophyta. Makroalga Bornetella nitida memiliki Indeks Nilai Penting 39, 24% mendominasi di lokasi penelitian. Keanekaragaman Shannon-Wiener (H’) spesies makroalga di Stasiun I (H’:3,02) tergolong tinggi sedangkan pada Stasiun II (H’:2,86)  dan Stasiun III (H’:2,63) tergolong sedang. Secara keseluruhan, keanekaragaman spesies makroalga di Kecamatan Tabukan Selatang tergolong tinggi (H’:3,00). Kata kunci:   struktur makroalga, Pantai Karurung, Pantai Palareng, Pantai Galoghong,Tabukan Selatan Abstract Marine macroalgae are marine plant-like organisms that has no true roots, stems, or leaves. The human ativities of macroalgae utilization, land conversion, and sea transportation can cause of macroalgae biodiversity decline. The purpose of this study was to analyze the structure and distribution of macroalgae in seagrass ecosystems at South Tabukan District, Sangihe Islands Regency, North Sulawesi. The research locations were at three research stations, i.e. Karurung Beach - Salurang Village, Palareng Beach - Palareng Village and Galoghong Beach - Batuwingkung Village. The study was conducted in November-December 2018 with line transect method sampling and quadrate sampling technique. Macroalgae were 36 species consists of 25 species of Chlorophyta Division, nine (9) species of Rhodophyta Division and two (2) species of Phaeophyta Division. Macroalga Bornetella nitida had Importance Value Index 39.24% that dominated research locations. The Shannon-Wiener biodiversity Index (H’) of macroalgae species at Station I (H': 3.02) was classified as high while Station II (H': 2.86) and Station III (H ': 2.63) were moderate. Overall, macroalgae species diversity at Tabukan Selatang District was high (H’: 3.00). Keywords: Macroalgae structure, Macroalgae distribution, Karurung Beach, Palareng Beach, Galoghong Beach, South Tabukan

scholarly journals Pre-emergence application of (thio)urea analogues compromises the development of the weed species Bidens pilosa, Urochloa brizantha, and Urochloa decumbens

2019 ◽  
Vol 17 ◽  
pp. 95-102
Author(s):  
Dandara R. Muniz ◽  
Janaina S. Garcia ◽  
Taniris C. Braga ◽  
Ângelo de Fátima ◽  
Luzia V. Modolo
Keyword(s):  
Weed Species ◽  
Bidens Pilosa ◽  
Urochloa Decumbens ◽  
Urochloa Brizantha

scholarly journals Allelopathy of aqueous Pachyrhizus erosus L. extracts on Euphorbia heterophylla and Bidens pilosa

2018 ◽  
Vol 48 (1) ◽  
pp. 59-65
Author(s):  
Jaqueline de Araujo Barbosa ◽  
Silvio Douglas Ferreira ◽  
Adriana Cologni Salvalaggio ◽  
Neumárcio Vilanova da Costa ◽  
Márcia de Moraes Echer
Keyword(s):  
Germination Rate ◽  
Germination Percentage ◽  
Tuberous Root ◽  
Allelopathic Effect ◽  
Root Extract ◽  
Weed Species ◽  
Bidens Pilosa ◽  
Randomized Design ◽  
Pachyrhizus Erosus ◽  
Dry Biomass

ABSTRACT Allelopathy contributes to the sustainable management of weeds in growing areas, due to its ability to inhibit the development of weed species. This study aimed to evaluate the allelopathic effect of Pachyrhizus erosus extract on Euphorbia heterophylla and Bidens pilosa germination. The experiment was carried out in a completely randomized design, in a 2 x 2 x 4 factorial scheme, with four replications. The first factor corresponded to the plant portion (shoot and tuberous root), the second to the extract preparation method (water at room temperature and boiling) and the third to the extract concentrations (0 %, 25 %, 50 % and 100 %). Phytochemical analyses were performed to identify the presence of secondary metabolites. The variables germination percentage, germination rate index and dry biomass decreased with increasing aqueous extract concentrations for both E. heterophylla and B. pilosa. When applied a P. erosus crude shoot extract (boiling), decreases of 18 % and 92 % were observed in the E. heterophylla and B. pilosa germination, respectively, with a decrease of 91 % in the dry biomass of E. heterophylla seedlings. The tuberous root extract (boiling), on the other hand, reduced the germination percentages for E. heterophylla and B. pilosa in 18 % and 80 %, respectively. The phytochemical evaluation indicated the presence of flavonoids, coumarins and saponins in the shoot and tuberous root extracts, while tannins were only observed in the shoot extract. Thus, it can be concluded that P. erosus extracts display an allelopathic effect on the weed species evaluated.

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