Studies on Weed Diversity and Phytosociology in Wheat Crop

2020 ◽  
Vol 7 (03) ◽  
Author(s):  
SANJEEV KUMAR ◽  
SHIVANI JAN
Keyword(s):  
Weed Management ◽  
Winter Season ◽  
Cropping System ◽  
Management Decision ◽  
Wheat Crop ◽  
Weed Species ◽  
Large Area ◽  
Importance Value Index ◽  
Importance Value ◽  
Phalaris Minor

Rice-wheat is the dominant cropping system in Patna district where wheat is generally grown in winter season and a large area is sown by using seed drill machines. The present investigation is based on the study of biodiversity of weeds under zero tilled condition in Patna district of Bihar. The weed inventory surveys and phytosociological studies in wheat fields were conducted during 2016-19 to identify the weed flora composition, density, frequency and Importance value index of 30 major weed species in wheat. In the study, Asteraceae was found as the largest family in respect of weed species whereas Poaceae and Leguminosaefamilystood at the second position in terms of weed species. Phytosociological studies further revealed that Phalaris minor (6.48) and Cynodon dactylon (5.03) have larger relative frequency among other weed species while Chenopodiumalbum(5.18)and Avena fatua(4.44)have larger relative abundance in the study area. Studies on relative density of weeds revealed that densities of Phalaris minor (7.06) and Chenopodium album (5.65) were higher over other weed species and similar trends were also observed in respect of Importance value index of weeds. Therefore, while planning effective weed management strategy, these two weeds (P. minor and C. album) must be focused. The study will provide an appraisal of species through quantitative characters and will allow effective weed management decision.

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

2020 ◽  
Vol 27 (2) ◽  
pp. 47-59 ◽  
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.

scholarly journals Mapping Phalaris minor under the Rice-Wheat Cropping System in different Agro-Ecological Regions of Nepal

2009 ◽  
Vol 7 ◽  
pp. 54-63 ◽  
Author(s):  
JD Ranjit ◽  
RR Bellinder ◽  
P Hobbs ◽  
NK Rajbhandari ◽  
P Kataki
Keyword(s):  
Weed Management ◽  
Negative Impact ◽  
Wheat Yield ◽  
Cropping System ◽  
Wheat Crop ◽  
Growth Stages ◽  
Wheat Seedlings ◽  
Phalaris Minor ◽  
Research Journal ◽  
Frequent Monitoring

A survey was conducted in order to map the spread of Phalaris minor in wheat in nine districtsin the mid-hill, Terai and inner Terai areas of the rice-wheat cropping system in Nepal during1998/99. Both qualitative and quantitative data were collected from 540 farmers and P. minorwas recorded in all of the nine surveyed districts. Percent summed dominance ratio (SDR) andaverage number per unit area (m2) of P. minor was compared to different districts of mid-hills,inner Tarai, and Tarai belts along with other weeds in the wheat crop. P. minor ranked as thefirst and second important weed of wheat that reduced the wheat yield from 10 to 50 percent. Itspopulations varied from district to district. However, the infestation appeared to be in increasingtrend. Future strategies need to consider in increasing growers' abilities to identify P. minor atearly growth stages when it is particularly difficult to differentiate from wheat seedlings. It issuggested that frequent monitoring of weeds in different tillage and weed management practicesshould be initiated. Besides farmers' training in the future there needs to be emphasis placed onincreasing farmer's awareness on the serious negative impact of P. minor on wheat yield andquality.Key words: Agro-ecology; Phalaris minor; survey; weeds; wheatDOI: 10.3126/narj.v7i0.1869Nepal Agriculture Research Journal Vol.7 2006 pp.54-63

scholarly journals Weeds Hosting the Soybean Cyst Nematode (Heterodera glycines Ichinohe): Management Implications in Agroecological Systems

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 146
Author(s):  
Leonardo F. Rocha ◽  
Karla L. Gage ◽  
Mirian F. Pimentel ◽  
Jason P. Bond ◽  
Ahmad M. Fakhoury
Keyword(s):  
Weed Management ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Integrated Management ◽  
Cropping System ◽  
Cyst Nematode ◽  
Weed Species ◽  
Initial Inoculum ◽  
Herbicide Resistant ◽  
Sites Of Action

The soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is a major soybean-yield-limiting soil-borne pathogen, especially in the Midwestern US. Weed management is recommended for SCN integrated management, since some weed species have been reported to be hosts for SCN. The increase in the occurrence of resistance to herbicides complicates weed management and may further direct ecological–evolutionary (eco–evo) feedbacks in plant–pathogen complexes, including interactions between host plants and SCN. In this review, we summarize weed species reported to be hosts of SCN in the US and outline potential weed–SCN management interactions. Plants from 23 families have been reported to host SCN, with Fabaceae including most host species. Out of 116 weeds hosts, 14 species have known herbicide-resistant biotypes to 8 herbicide sites of action. Factors influencing the ability of weeds to host SCN are environmental and edaphic conditions, SCN initial inoculum, weed population levels, and variations in susceptibility of weed biotypes to SCN within a population. The association of SCN on weeds with relatively little fitness cost incurred by the latter may decrease the competitive ability of the crop and increase weed reproduction when SCN is present, feeding back into the probability of selecting for herbicide-resistant weed biotypes. Therefore, proper management of weed hosts of SCN should be a focus of integrated pest management (IPM) strategies to prevent further eco–evo feedbacks in the cropping system.

scholarly journals Weeds and Their Effect on the Performance of Maize and Finger Millet in Mid-Hills of Nepal

2014 ◽  
Vol 2 (3) ◽  
pp. 275-278 ◽  
Author(s):  
Tika Bahadur Karki ◽  
Shrawan K. Sah ◽  
Resam B. Thapa ◽  
Andrew J. McDonald ◽  
Adam S. Davis ◽  
...  
Keyword(s):  
Weed Management ◽  
Crop Production ◽  
Finger Millet ◽  
Crop Yields ◽  
Management Strategies ◽  
Cropping System ◽  
Weed Species ◽  
Ageratum Conyzoides ◽  
Alternative Crop ◽  
Weed Infestation

Relay cropping of maize with fingermillet (maize/fingermillet) is the predominant cropping system for sustaining food security situation in the hilly regions of Nepal. In this region weed pressure severely reduces crop yields. Basic information on weed species composition, biomass production and their effect on crop yields and economics are lacking for this region. This information will be necessary to develop effective weed management strategies for the future. In light of this an empirical study was carried out in two representatives mid hill districts of Parbat and Baglung during summer season of 2010/2011 in Nepal. A total of 10 major weed species with densities of 172 in Parbat and 311 per 0.25m2 area in Baglung were observed. The highest percentage of both relative and absolute densities were recorded for Ageratum conyzoides in Parbat and Polygonum chinensis in Baglung. Weed infestation under farmers practice of crop management reduced the grain yield of maize by 1.985 Mt ha-1 (117%) in Baglung and 1.760 Mt ha-1 (108%) in Parbat. Similarly, in finger millet it was 0.489 Mt ha-1 (63%) in Baglung and 0.403 Mt ha-1 in Parbat. Similarly, the combined yield of both the crops was also significantly reduced by 79.3% and 61.7% in Baglung and Parbat respectively. Hence, weeds are directly affecting the crop performance in the region. Therefore, there is an urgent need to develop an alternative crop production system in the hills. DOI: http://dx.doi.org/10.3126/ijasbt.v2i3.10790Int J Appl Sci Biotechnol, Vol. 2(3): 275-278  

scholarly journals Phytosociology in Degraded and Renewed Pastures in Agrosilvopastoral Systems

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
R.C. DIAS ◽  
M.V. SANTOS ◽  
E.A. FERREIRA ◽  
T.G.S BRAZ ◽  
L.V. FIGUEIREDO ◽  
...  
Keyword(s):  
Similarity Index ◽  
Weed Species ◽  
Importance Value Index ◽  
Importance Value ◽  
Brachiaria Decumbens ◽  
Agrosilvopastoral Systems ◽  
Before And After ◽  
One Year ◽  
Sida Cordifolia

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.

The role of management in yield improvement of the wheat crop—a review with special emphasis on Western Australia

2005 ◽  
Vol 56 (11) ◽  
pp. 1137 ◽  
Author(s):  
W. K. Anderson ◽  
M. A. Hamza ◽  
D. L. Sharma ◽  
M. F. D'Antuono ◽  
F. C. Hoyle ◽  
...  
Keyword(s):  
Western Australia ◽  
Weed Management ◽  
Water Conservation ◽  
Grain Quality ◽  
Crop Residues ◽  
Cropping System ◽  
Rate Of Change ◽  
Wheat Crop ◽  
Positive Interactions

Modern bread wheat (Triticum aestivum) has been well adapted for survival and production in water-limited environments since it was first domesticated in the Mediterranean basin at least 8000 years ago. Adaptation to various environments has been assisted through selection and cross-breeding for traits that contribute to high and stable yield since that time. Improvements in crop management aimed at improving yield and grain quality probably developed more slowly but the rate of change has accelerated in recent decades. Many studies have shown that the contribution to increased yield from improved management has been about double that from breeding. Both processes have proceeded in parallel, although possibly at different rates in some periods, and positive interactions between breeding and management have been responsible for greater improvements than by either process alone. In southern Australia, management of the wheat crop has focused on improvement of yield and grain quality over the last century. Adaptation has come to be equated with profitability and, recently, with long-term economic and biological viability of the production system. Early emphases on water conservation through the use of bare fallow, crop nutrition through the use of fertilisers, crop rotation with legumes, and mechanisation, have been replaced by, or supplemented with, extensive use of herbicides for weed management, reduced tillage, earlier sowing, retention of crop residues, and the use of ‘break’ crops, largely for management of root diseases. Yields from rainfed wheat crops in Western Australia have doubled since the late 1980s and water-use efficiency has also doubled. The percentage of the crop in Western Australia that qualifies for premium payments for quality has increased 3–4 fold since 1990. Both these trends have been underpinned by the gradual elimination or management of the factors that have been identified as limiting grain yield, grain quality, or long-term viability of the cropping system.

scholarly journals WEED INCIDENCE AFTER SOYBEAN HARVEST IN NO-TILL AND CONVENTIONAL TILLAGE CROPROTATION SYSTEMS IN RORAIMA’S CERRADO

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
J.A.A. ALBUQUERQUE ◽  
T.S. SANTOS ◽  
T.S. CASTRO ◽  
V.F. MELO ◽  
P.R.R. ROCHA
Keyword(s):  
Similarity Index ◽  
Dry Mass ◽  
Conventional Tillage ◽  
Weed Species ◽  
Importance Value Index ◽  
Importance Value ◽  
No Till ◽  
Rotational Systems ◽  
Botanical Classification

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.

Diversity of Weeds and Population Dynamics of Predators and Prey Present in Wheat-Mustard Ecosystem at Paklihawa, Rupandehi, Nepal

2018 ◽  
Vol 35 (1) ◽  
pp. 173-181
Author(s):  
S. Khanal ◽  
S. Adhikari ◽  
A. Bhattarai ◽  
S. Shrestha
Keyword(s):  
Population Dynamics ◽  
Chenopodium Album ◽  
Effect Of Temperature ◽  
Weed Species ◽  
Importance Value Index ◽  
Importance Value ◽  
Mustard Aphid ◽  
Wooden Frame ◽  
Index Value ◽  
The Given

A study was conducted at Institute of Agriculture and Animal Science (IAAS), Paklihawa Rupandehi, agronomy field to study the diversity of weeds and population dynamics of predators and prey in wheat-mustard ecosystem. The study was conducted by quadrate sampling method using the wooden frame by selecting 40 sample spots, and locating its coordinates. Predator, prey, some of the beneficial and harmful insects as well as weed species was recorded in 5 days interval in the study. Relationships between the population of the mustard aphid and wheat aphid, lady bird beetle to maximum and minimum temperature were recorded in order to know the effect of temperature in relation to population density. Number of mustard aphid and its nymph has shown the positive significant relationship with the population of the spider in the wheat mustard ecosystem. Shannon Weiner Index value was calculated and the species richness was found to be 2.63 with the effective number of species value 9. The species evenness value was found to be 0.83 in the studied ecosystem which signifies that the given weed ecosystem is somewhat even. The importance value index (IVI) of the given ecosystem with the value of different weed species was calculated and it was found that the weed Anagalis arvensis was ranked as first with the IVI value of 57.98 following Vicia sativa and Chenopodium album. This signifies that the species Anagalis arvensis has greater control over the wheat mustard ecosystem of Paklihawa, Rupandehi.

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

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
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.

scholarly journals OCORRÊNCIA DE PLANTAS DANINHAS NA CULTURA DO FEIJÃO-CAUPI SOB QUATRO MANEJOS NA AMAZÔNIA OCIDENTAL

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 ◽  
...  
Keyword(s):  
Vigna Unguiculata ◽  
Weed Management ◽  
Control Strategies ◽  
Similarity Index ◽  
Natural Vegetation ◽  
Importance Value Index ◽  
Importance Value ◽  
No Till ◽  
Before And After ◽  
Herbicide Glyphosate

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.

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