Infestation of weed species in pre-planting of soybean in succession to winter crops

This study aimed to evaluate different crops and plant species planted after soybeans for one year, in terms of their potential to inhibit the occurrence of weed species. The following crops that were planted as second crop after soybeans were evaluated: (1) corn (Zea mays) planted at spacing of 90 cm between rows, intercropped with Brachiaria ruziziensis in the inter-rows; (2) sunflower (Helianthus annuus); (3) crambe (Crambe abyssinica); (4) radish (Raphanus sativus); (5) rapeseed (Brassica napus); and (6) winter fallow - no plantation after soybeans. Phytosociological characterization of weed species was carried out at the pre-planting of soybeans in the following cropping season. Estimations of relative abundance, relative frequence, relative dominance and Importance Value Index were made for each species present. Areas were also intra-characterized by the diversity coefficients of Simpson and modified Shannon-Weiner, and areas were compared using the Jaccard similarity coefficient for presence-only, by multivariate cluster analysis. In the short‑term (a single cropping season), cultivation of winter crops do contribute for lower occurrence of weed species at the pre-planting of soybeans on the subsequent cropping season. The suppressive effects depend both on the species grown in the winter and in the amount of straw left on the soil by these winter crops. Radish was more efficient in inhibiting the occurrence of weed species and rapeseed showed composition of infestation similar to that observed at the area under fallow.

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Phytosociology in Degraded and Renewed Pastures in Agrosilvopastoral Systems

Planta Daninha ◽

10.1590/s0100-83582018360100075 ◽

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.

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Occurrence of weed species in Jatropha curcas intercropping systems

Planta Daninha ◽

10.1590/s0100-83582014000200010 ◽

2014 ◽

Vol 32 (2) ◽

pp. 327-334 ◽

Cited By ~ 2

Author(s):

G. Concenço ◽

C.J. Silva ◽

I.V.T. Correia ◽

J.A.N. Silva ◽

S.A. Santos ◽

...

Keyword(s):

Crop Rotation ◽

C:N Ratio ◽

Panicum Maximum ◽

Weed Species ◽

Importance Value Index ◽

Crambe Abyssinica ◽

Mato Grosso ◽

Rotation System ◽

Brachiaria Ruziziensis ◽

Crop Rotation System

This study aimed to evaluate the level of infestation by weed species in a consolidated Jatropha plantation, as a function of the plant species grown in interrows. The experiment was installed in 2006 at the district of Itahum, city of Dourados, state of Mato Grosso do Sul, Brazil, made possible through a partnership between Embrapa Western Agriculture and Paraiso Farm. Treatments consisted of (1) Jatropha in monocrop, with no plant at the interrrows; or the following plants cultivaded at the interrows of Jatropha: (2) Stylosanthes spp.; (3) Brachiaria ruziziensis; (4) Brachiaria ruziziensis + Stylosanthess pp.; (5) Brachiaria humidicola; (6) Panicum maximum cv. massai; (7) Cajanus cajan cv. anão; (8) Crotalaria spectabilis; (9) Crop rotation system 1 - (maize second crop -Crambe abyssinica - soybean - peanut); and (10) Crop rotation system 2 - (cowpea - radish - maize - cowpea) conducted for two years. Phytosociological characterization of weed species was accomplished in 2011 based on the Ecological Approach. Estimations of relative abundance, frequency, dominance and Importance Value Index were obtained. Areas were also characterized by the diversity coefficients of Simpson and modified Shannon-Weiner, and then grouped by cluster analysis. Areas with low soil coverage resulted in higher infestation levels; crop rotation in the interrows of Jatropha produced a significant reduction in weed infestation, but the lowest infestation levels were observed when grasses were grown intercropped with Jatropha. Lower diversity coefficients were associated with occurrence of the most troublesome weed species. In the first years after planting Jatropha, species of Brachiaria or a crop rotation involving species with high mulching ability and whose biomass exhibit a high C:N ratio, should be established in the interrows to avoid problems with weeds infestation.

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

Planta Daninha ◽

10.1590/s0100-83582017350100034 ◽

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.

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

Journal of the Institute of Agriculture and Animal Science ◽

10.3126/jiaas.v35i1.22538 ◽

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.

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Weeds occurrence in areas submitted to distinct winter crops

Planta Daninha ◽

10.1590/s0100-83582012000400008 ◽

2012 ◽

Vol 30 (4) ◽

pp. 747-755 ◽

Cited By ~ 1

Author(s):

G. Concenço ◽

C.J. Silva ◽

L.A. Staut ◽

C.S. Pontes ◽

L.C.A.S. Laurindo ◽

...

Keyword(s):

Conventional Tillage ◽

Western Region ◽

Weed Species ◽

Absolute Level ◽

Oilseed Crops ◽

No Till ◽

Cropping Season ◽

Tillage System ◽

Winter Crops ◽

Winter Fallow

In the Western Region of Brazil, it is usual to have two agricultural harvests in the same cropping season. Usually the first crop is soybean, followed by corn. In areas where corn is not planted due to a delayed harvest of soybean, farmers generally do not use winter crops. For these areas, the planting of winter oilseed crops aiming at the production of bio-fuels is one of the best alternatives; in addition, this would help in reducing the occurrence of weed species at the following summer crop. This study aimed to assessing the weed community in distinct winter crops post soybean crop, in terms of species composition, level of infestation and severity of occurrence. The following treatments were evaluated: agriculture under a no-till system with winter fallow, winter oilseed crops (crambe, radish, rapeseed) with no-till agriculture in the summer, and agriculture under a conventional tillage system with winter fallow. Phytosociological evaluations of all treatments were carried out 75 DAE of the oilseed crops, and the diversity indexes of Margalef, Menhinick, Simpson, and Shannon-Weiner were determined. Areas were also grouped by cluster analysis based on UPGMA applied at Jaccard's similarity matrix. Among the treatments with winter coverage, radish was the most efficient crop in suppressing the occurrence of weed species. The area with conventional tillage agriculture and winter fallow allowed for a higher occurrence of troublesome weeds. On the other hand, the area under fallow showed the highest absolute level of infestation. Overall, oilseed crops in the winter contribute to lower levels of infestation by weed species in these areas.

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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.

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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.

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Characterization of the Weed Flora in Rice Areas under Distinct Cropping Systems and Herbicide Managements

Planta Daninha ◽

10.1590/s0100-83582019370100089 ◽

2019 ◽

Vol 37 ◽

Author(s):

G. CONCENÇO ◽

A. ANDRES ◽

F. SCHREIBER ◽

A.F. SILVA ◽

I.S. MOISINHO ◽

...

Keyword(s):

Species Composition ◽

Crop Rotation ◽

Cover Crops ◽

Cropping Systems ◽

Conventional Tillage ◽

Ecological System ◽

Weed Species ◽

Cropping Season ◽

One Year ◽

Animal Presence

ABSTRACT: The aim of this study was to evaluate the occurrence of weeds in flooded rice areas, as a function of planting system and herbicide programmes in the previous cropping year. The experiment was installed in field conditions, in randomized complete blocks design, arranged in factorial scheme 3 x 2, with eight replications. In factor A, treatments consisted on conventional tillage, minimum tillage and no till cropping systems, coupled to the application (traditional control) or not (semi-ecological system) of herbicides (Factor B). One year after rice cultivation, preceding the planting of the next cropping season, phytosociological evaluations of the weed communities present in the treatments were carried out. We assessed the overall infestation level and weed species composition, which were classified by their respective density, frequency and dominance abilities. We also estimated the diversity coefficients of Simpson and Shannon Weiner, and the sustainability coefficient of Shannon; treatments were also grouped by similarity in weed species composition. Rice growing systems (traditional or semi-ecological) promote remarkable differences in weed occurrence. Herbicide-based crops select specific companion weed species, but crop rotation or winter cover crops are not a sine qua non condition for success since a good herbicide programme is planned. For the Semi ecological system, crop rotation, thick winter soil mulching and association with animal presence and grazing are essential for the short, medium and long-term inhibition of weeds.

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Weed phytosociology in diversified soybean production systems

Semina Ciências Agrárias ◽

10.5433/1679-0359.2021v42n6supl2p3567 ◽

2021 ◽

Vol 42 (6supl2) ◽

pp. 3567-3580

Author(s):

Ivan Bordin ◽

◽

Osmar Maziero Buratto ◽

Andreia Cristina Peres Rodrigues da Costa ◽

Benedito Noedi Rodrigues ◽

...

Keyword(s):

Management Practices ◽

Production Systems ◽

Integrated Management ◽

Management Strategies ◽

Suppressive Effect ◽

Ecological Interactions ◽

Weed Species ◽

Importance Value Index ◽

Importance Value ◽

Commelina Benghalensis

The knowledge of the impacts of the management practices used in each agricultural production system on the ecological interactions between commercial crops and weed populations can assist in the development of specific and sustainable integrated management strategies. This study aimed to assess weed communities in soybean in succession to second-crop corn and production systems with crop diversification in Northern Paraná State. The study was conducted during three agricultural years (2014/2017). Six treatments were setup: 1 – corn/soybean, corn/soybean, and corn/soybean), 2 – white oat/soybean, rye/corn, and wheat/soybean, 3 – oat + rye/soybean, oat + radish/corn, and congo grass/soybean, 4 – canola/corn, crambe/corn, and safflower/soybean, 5 – buckwheat/ radish/corn, bean/soybean, and buckwheat/oat/soybean, and 6 – wheat/corn + congo grass, canola/corn, and bean/soybean. The relative importance value index of each weed species and the soil cover (soil, straw, and weeds) were assessed. The experimental design consisted of randomized blocks with four replications of 300 m2 (20 × 15 m). The production systems white oat/soybean, rye/corn, and wheat/soybean; buckwheat/radish/corn, bean/soybean, buckwheat/oat/soybean; and wheat/corn+congo grass, canola/corn, bean/soybean had a suppressive effect on the species Commelina benghalensis. Euphorbia heterophylla and Digitaria horizontalis were the species most adapted to the assessed production systems. Seeds remaining from crambe and radish cultivations became volunteer plants in subsequent cultivations.

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Technology Levels in Cassava Cultivation Alter Phytosociology of Weeds

HortScience ◽

10.21273/hortsci15643-20 ◽

2021 ◽

pp. 1-8

Author(s):

Isabel Schlegel Werle ◽

Alencar Junior Zanon ◽

Nereu Augusto Streck ◽

Carlos Eduardo Schaedler ◽

Felipe Schmidt Dalla Porta ◽

...

Keyword(s):

Field Experiments ◽

Weed Species ◽

Importance Value Index ◽

Importance Value ◽

Dissimilarity Matrix ◽

Weed Diversity ◽

Poaceae Family ◽

Cassava Production ◽

Technology Level ◽

Santa Maria

This study aimed to assess the phytosociology of weeds as a function of different crop management technology levels in cassava production. Field experiments were conducted in Santa Maria (29°41′03″ S; 53°48′25″ W) and Itaqui (lat. 29°07′31″ S; long. 56°33′11″ W), Rio Grande do Sul, Brazil. Treatments consisted of three technology levels: low (postemergence weeding without basal dressing); medium (weeding performed at 7 and 40 days after planting and fertilization with 6.25, 25, and 25 kg⋅ha−1 of N, P, and K, respectively); and high (postemergence application of s-metolachlor; 1250 kg⋅ha−1 of lime and 12.5, 50, and 50 kg⋅ha−1 of N, P, and K, respectively). Weed frequency, density, relative abundance, and importance values were calculated for each location. Then, locations were compared using a dissimilarity matrix. Weed density and diversity decreased linearly as technology levels increased. The predominant weed species found in Itaqui and Santa Maria belong to the Poaceae family. Itaqui presented highest weed diversity among the locations. The genus Cyperus had the highest importance value index in Santa Maria. The use of S-metolachlor at the high technology level provided a lower frequency and lower diversity of weed species than did levels without chemical control in Itaqui and Santa Maria.

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