Competitiveness of alexandergrass or Bengal dayflower with soybean

Weeds compete with field crops mainly for water, light and nutrients, and the degree of competition is affected by the weed density and the intrinsic competitive ability of each plant species in coexistence. The objective of this research was to compare the competitiveness of alexandergrass (Brachiaria plantaginea) or Bengal dayflower (Commelina benghalensis) in coexistence with soybean, cv. M-Soy 8045. A factorial experiment (2 x 5) with two weed species and five competition proportions was carried out in a completely randomized design with four replicates. Proportions were based on a replacement series competition design, always maintaining the total density of four plants per 10 L plastic pots, which corresponded to 60 plants m ². The weed-crop proportions were: 0:4; 1:3; 2:2; 3:1; 4:0; that corresponded to the proportion of 100, 75, 50, 25 and 0% of soybean plants and the opposite for weeds, B. plantaginea or C. benghalensis plants. Leaf area, shoot dry mass of the weeds and soybean and number of soybean trifoliate leaves were evaluated when the soybean reached the phenologic stage of full flowering. B. plantaginea was a better competitor than soybean plants. Otherwise, C. benghalensis revealed a similar competitive ability that of the soybean. In both cases, there were evidences that intraspecific competition was more important.

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Competitive ability of corn in coexistence with goosegrass

Planta Daninha ◽

10.1590/s0100-83582013000200005 ◽

2013 ◽

Vol 31 (2) ◽

pp. 281-289 ◽

Cited By ~ 10

Author(s):

A.C.D. Wandscheer ◽

M.A. Rizzardi ◽

M. Reichert

Keyword(s):

Plant Height ◽

Competitive Ability ◽

Dry Mass ◽

Agricultural Systems ◽

Weed Species ◽

Replacement Series ◽

Eleusine Indica ◽

Randomized Design ◽

Completely Randomized Design ◽

Corn Plants

Competition between plants is one of the main interferences that occurs in agricultural systems and accounts for significant crop yield reductions. The aim of this study was to assess the competitive ability of corn in coexistence with the weed species Eleusine indica. The experiments were conducted in a greenhouse, in the growing season 2010/2011, and were arranged in a completely randomized design with four replications. The experimental units consisted of plastic pots with a volumetric capacity of 8 L. Treatments were arranged in a replacement series with five proportions of corn plants and weed: 100:0, 75:25, 50:50, 25:75, and 0:100, respectively, with a constant population of eight plants per pot, at the end of each treatment. The competitiveness analysis was conducted through diagrams applied to the replacement series experiment and competitiveness index, and the variables evaluated were root, shoot, and total dry mass, and plant height. When in equal proportions, corn showed competitive ability equivalent to goosegrass in relation to the variables shoot, root, and total dry mass. Goosegrass was more competitive than the crop in relation to plant height.

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Does the resistance to glyphosate herbicide affect the competitive ability of ryegrass with soybean?

Planta Daninha ◽

10.1590/s0100-83582014000100021 ◽

2014 ◽

Vol 32 (1) ◽

pp. 189-196 ◽

Cited By ~ 2

Author(s):

C. Oliveira ◽

D. Agostinetto ◽

L. Vargas ◽

L.A. Ávila ◽

C.P. Tarouco

Keyword(s):

Statistical Analysis ◽

Leaf Area ◽

Intraspecific Competition ◽

Competitive Ability ◽

Dry Mass ◽

Replacement Series ◽

Soybean Crop ◽

Randomized Design ◽

Glyphosate Herbicide ◽

Completely Randomized Design

The objective this work was to investigate the competitive ability between resistant and susceptible ryegrass biotypes and of these with soybean crop. Four experiments were carried under greenhouse, in a completely randomized design with four replications, in 2011 and 2012. Treatments were arranged in additive series and replacement series assay. In each series, the proportions among ryegrass resistant and susceptible plants related to soybean were: 100:0, 75:25, 50:50, 25:75 e 0:100. Leaf area and shoot dry mass were evaluated. Competitiveness statistical analysis consisted in applying diagrams to the replacement series and alternative interpretations of the competitiveness indexes. The soybean crop had equivalent competitiveness to the susceptible ryegrass biotype and inferior to the resistant biotype, while the biotypes, both susceptible and resistant to glyphosate, present equivalent competitive ability. In general, the intraspecific competition is more harmful to ryegrass when in competition with soybean, while interspecific competition is predominant for culture.

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COMPETITIVE ABILITY OF CANOLA HYBRIDS WITH WEEDS

Planta Daninha ◽

10.1590/s0100-83582015000300004 ◽

2015 ◽

Vol 33 (3) ◽

pp. 413-423 ◽

Cited By ~ 2

Author(s):

L. GALON ◽

L. R. AGAZZI ◽

L. VARGAS ◽

F. NONEMACHER ◽

F. J. M. BASSO ◽

...

Keyword(s):

Leaf Area ◽

Competitive Analysis ◽

Raphanus Sativus ◽

Competitive Ability ◽

Lolium Multiflorum ◽

Dry Mass ◽

Replacement Series ◽

Randomized Design ◽

Competition Ability ◽

Completely Randomized Design

ABSTRACTThe objective of the study was to assess the relative competitive ability of canola hybrids in the presence of turnip (Raphanus sativus) and ryegrass (Lolium multiflorum) in different ratios of plants in the mixture. The experiments were conducted in a greenhouse, in a completely randomized design with four replications. Treatments were arranged in ratios of canola against turnip or ryegrass: 100:0, 75:25, 50:50, 25:75 and 0:100. Competitive analysis of the species was accomplished by means of diagrams usually applied to replacement series and also by the relative competitiveness indices. Fifty days after the emergence of the species, measurements of leaf area and shoot dry mass were performed. There was a competition between canola hybrids and weeds, with reduction for all variables. There was a differential competitive ability among canola hybrids in the presence of turnip and/or ryegrass. Canola hybrid Hyola 433 was more competitive in the presence of turnip than Hyola 61, 76 and 571 CL. Hyola 61, 76, 433 and 571 CL do not differ in terms of competition ability when growing with ryegrass.

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INFLUENCE OF SUGARCANE STRAW AND SOWING DEPTH ON THE EMERGENCE OF WEED SPECIES

Planta Daninha ◽

10.1590/s0100-83582015000300003 ◽

2015 ◽

Vol 33 (3) ◽

pp. 405-412 ◽

Cited By ~ 2

Author(s):

P. V. SILVA ◽

P. A. MONQUERO ◽

F. B. SILVA ◽

N. C. BEVILAQUA ◽

M. R. MALARDO

Keyword(s):

Ricinus Communis ◽

Seedling Emergence ◽

Dry Mass ◽

Weed Species ◽

Sowing Depth ◽

Sugarcane Straw ◽

Randomized Design ◽

Significant Difference ◽

Completely Randomized Design ◽

Luffa Aegyptiaca

ABSTRACT This study aimed to understand the influence of sowing depth and the amount of sugarcane straw on the emergence of weed species Luffa aegyptiaca Miller (Cucurbitaceae); Mucuna aterrima Piper & Tracy (Fabaceae - Leguminosae) and Ricinus communis (Euphorbiaceae). A completely randomized design with a 5 x 4 x 3 factorial layout with four replications was used, at five sowing depths (0, 2, 4, 8 and 10 cm), four different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) and three different evaluation periods (7, 14 and 21 days after sowing). After sowing, different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) were deposited on soil. Seedling emergence was analyzed at 7, 14 and 21 days after sowing, counting the number of seedlings that had emerged. At the end of the trial, weed height (cm), leaf area (cm2) and shoot dry mass (g) were measured. In relation to emergence ability, studied species presented different responses according to sowing depth and to the amount of sugarcane straw deposited on the soil. For the L.aegyptiacaand M.aterrima, no significant difference was observed in the interaction between depth and sugarcane straw, showing the adaptation of these species to no-burn sugarcane system. For R.communis, seeds placed at 0 cm of sugar cane straw depth were observed to favor the emergence of seedlings.

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Soybeans Competitiveness with Morning Glory

Planta Daninha ◽

10.1590/s0100-83582016340100003 ◽

2016 ◽

Vol 34 (1) ◽

pp. 25-33

Author(s):

F. PICCININI ◽

T.N. MARTIN ◽

S.L.O. MACHADO ◽

N.D. KRUSE ◽

R. SCHMATZ

Keyword(s):

Leaf Area ◽

Dry Mass ◽

Morning Glory ◽

Replacement Series ◽

Yield And Quality ◽

Randomized Design ◽

Total Plant ◽

Soybean Plants ◽

Herbicide Use

Weeds interfere negatively on development, yield and quality of soybeans (Glycine max). Inadequate weed control by herbicide use can select for resistant or tolerant biotypes, leading to a shift in the weed flora. An example is the increase of incidence of morning glory (Ipomoea spp.) in soybeans growing areas in South Brazil. The aim of this study was to determine the competitiveness of soybeans intercropped with I. triloba, I. indivisa and I. purpurea through a replacement experiments series. Greenhouse experiments were conducted in a completely randomized design with four replications. The first experiment was carried out aiming to get the plant population while total plant dry mass remained constant. Other experiments were done under replacement series experiments with soybeans and morning glory ratios of 100:0, 75:25, 50:50, 25:75 and 100:0 using the 250 plant m-2 defined by the preliminary experiment. Leaf area, root and shoots dry mass were assessed. Diagrams along with index interpretation were used to performed a competitiveness analysis. Soybeans showed greater competitiveness as I. triloba, I. purpurea and I. indivisa species for the leaf area, root and shoots dry mass variables. Intraspecific competition prevails between soybean plants whilst interspecific competition prevails for morning glory.

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Interference of Brassicaceae and Poaceae on Canola Hybrids

Planta Daninha ◽

10.1590/s0100-83582019370100085 ◽

2019 ◽

Vol 37 ◽

Author(s):

D.R.O. SILVA ◽

A.C.M. AGUIAR ◽

D.P. GHELLER ◽

B.D. NOVELLO ◽

C.J. BASSO

Keyword(s):

Dry Matter ◽

Competitive Ability ◽

Shoot Growth ◽

Weed Species ◽

Orthogonal Contrasts ◽

Light Interference ◽

Randomized Design ◽

Number Of Leaves ◽

Hybrid Growth ◽

Completely Randomized Design

ABSTRACT: The objective of this study was to evaluate the initial competitive ability of canola hybrids against Brassicaceae and Poaceae species in terms of root and shoot resources. Two experiments were conducted in greenhouse, in a completely randomized design with four replications. The treatments consisted of interference conditions by root + shoot interference (root+shoot) and shoot interference (Light); and Brassicaceae and Poaceae weeds competing with hybrid of canola (Hyola 61 and Diamond) with different traits for competitiveness. The plant height, root length, dry matter of shoot and root, number of leaves and leaf area were evaluated. Data were compared using orthogonal contrasts. The turnip and volunteer canola reduced root development of the Hyola 61 in root + shoot interference, and among the Brassicaceas weeds, turnip caused greater losses. Brassicaceas weeds caused largest reductions in Diamond’s hybrid growth compared to Poaceae, mainly under light interference. Brassicaceas and Poaceae weeds cause similar damage to Hyola 61 hybrid, and the injury is higher for root +shoot interference. The black oat induce shoot growth in the Diamond hybrid under shoot interference, while among the Brassicaceae weed species, there were no differences.

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Competition of Amaranthus species with dry bean plants

Scientia Agricola ◽

10.1590/s0103-90162008000300003 ◽

2008 ◽

Vol 65 (3) ◽

pp. 239-245 ◽

Cited By ~ 18

Author(s):

Saul Jorge Pinto de Carvalho ◽

Pedro Jacob Christoffoleti

Keyword(s):

Competitive Ability ◽

Total Density ◽

Weed Species ◽

Replacement Series ◽

Dry Bean ◽

Series Design ◽

Bean Plants ◽

Species Proportions ◽

Expanded Cotyledon ◽

Vegetal Species

Weeds compete with field crops mainly for water, light and nutrients, and this competition is among other factors, a function of the occurrence of weed density, and the intrinsic competitive ability of each vegetal species. The objective of this research was to evaluate the competitive ability of five weed species of the Amaranthus L. genus (A. deflexus, A. hybridus, A. retroflexus, A. spinosus and A. viridis) with dry bean plants (Phaseolus vulgaris L. - 'Carioca Precoce' cultivar), using the replacement series design. A fixed total density equivalent to 80 plants m-2 was used in pots of 2.8 L capacity varying the proportions between the species in coexistence. To install the experiment, Amaranthus seedlings were transplanted to the pots at the phenological stage of completely expanded cotyledon leaves, while the crop was seeded. A factorial scheme (5 x 5) was used to carry out the experiment, consisting of five species of Amaranthus (pigweeds) and five species proportions (beans:pigweeds): 4:0, 3:1, 2:2, 1:3 and 0:4. Randomized blocks with four replicates were installed and the experiment was repeated twice. Dry bean plants were more competitive than each one of the five Amaranthus species when the species proportion was equivalent. A. deflexus and A. viridis were the weed species which phenology were less affected by the competition with dry bean; the intraspecific competition was more damaging for dry bean plants, suggesting that the damages caused by the weeds are more related to high density of infestation than to the intrinsic competitive ability of the species.

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COMPETITIVE ABILITY OF WHEAT IN ASSOCIATION WITH BIOTYPES OF Raphanus raphanistrum L. RESISTANT AND SUSCEPTIBLE TO ALS-INHIBITOR HERBICIDES

Ciência e Agrotecnologia ◽

10.1590/s1413-70542015000200003 ◽

2015 ◽

Vol 39 (2) ◽

pp. 121-130 ◽

Cited By ~ 3

Author(s):

Leandro Oliveira da Costa ◽

Mauro Antônio Rizzardi

Keyword(s):

Leaf Area ◽

Dry Matter ◽

Competitive Ability ◽

Management Strategies ◽

Raphanus Raphanistrum ◽

Replacement Series ◽

Herbicide Resistant ◽

Randomized Design ◽

Completely Randomized Design ◽

Als Inhibitor

The occurrence of Raphanus raphanistrum ALS herbicide-resistant in wheat crops causes crop yield losses, which makes it necessary to understand the factors that influence the interference of this weed to develop safer management strategies. This study aimed to evaluate the competitive ability of wheat in coexistence with biotypes of R. raphanistrum that are resistant (R biotype) and susceptible (S biotypes) to ALS herbicides and to determine whether there are differences in the competitiveness of these biotypes. The experiments were conducted in a greenhouse using a completely randomized design with four replications. The treatments were placed in pots and arranged in replacement series for three experiments (1 - wheat with the R biotype; 2 - wheat with the S biotype; and 3 - the R biotype with the S biotype) at the following ratios: 100:0, 75:25, 50:50, 25:75, and 0:100. The competitiveness was analyzed through diagrams applied to replacement experiments and competitiveness indices, including the evaluation of the shoot dry matter of the plants (experiments 1, 2, and 3) and the leaf area (experiment 3). The R and S biotypes significantly decreased the shoot dry matter of the wheat cultivar and demonstrated superior competitive ability compared with the culture. The interspecific competition was more important for the wheat and for the S biotype. The competitiveness of the R biotype compared to the S biotype was similar, with synergism in the leaf area production, which indicates the predominant intraspecific competition exhibited by the R biotype.

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Competitive interaction between commom black bean cultivars and Euphorbia heterophylla 1

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632018v4851669 ◽

2018 ◽

Vol 48 (3) ◽

pp. 254-260 ◽

Cited By ~ 1

Author(s):

Leandro Galon ◽

César Tiago Forte ◽

Francisco Wilson Reichert Júnior ◽

Ricardo Trevisol ◽

Gismael Francisco Perin

Keyword(s):

Leaf Area ◽

Chlorophyll Content ◽

Plant Height ◽

Growth And Development ◽

Competitive Ability ◽

Dry Mass ◽

Black Bean ◽

Randomized Design ◽

Bean Plants ◽

Completely Randomized Design

ABSTRACT Weeds can interfere in the growth and development of bean plants if not properly managed, especially the wild poinsettia (Euphorbia heterophylla L.). This study aimed to evaluate the competitive ability of black bean cultivars coexisting with wild poinsettia. The experiment was conducted in a greenhouse, in a completely randomized design, with four replications. Each treatment consisted of one bean plant of the BRS Campeiro, IPR Uirapuru or SCS Predileto cultivars, living with 0, 1, 2, 3, 4 or 5 wild poinsettia plants, corresponding to populations of 0 plants m-2, 22 plants m-2, 44 plants m-2, 66 plants m-2, 88 plants m-2 and 110 plants m-2. Bean and wild poinsettia plants were assessed for stem diameter, leaf area, chlorophyll content, plant height and shoot dry mass. The bean cultivars behaved differently when cultivated with distinct wild poinsettia populations. The SCS Predileto cultivar showed a higher competitive ability against the wild poinsettia than the BRS Campeiro and IPR Uirapuru, what can be verified by the reduction of leaf area and dry mass of the weed. On average, at a density of 110 plants m-2, the wild poinsettia reduces in approximately 32 % the leaf area and 50 % the dry mass of the bean plants.

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CHANGE IN PHYSIOLOGICAL FEATURES IN RYEGRASS BIOTYPES IN COMPETITION WITH SOYBEAN DUE RESISTANCE TO GLYPHOSATE

Planta Daninha ◽

10.1590/s0100-83582016340300012 ◽

2016 ◽

Vol 34 (3) ◽

pp. 517-526 ◽

Cited By ~ 4

Author(s):

D. AGOSTINETTO ◽

C. OLIVEIRA ◽

A.C. LANGARO ◽

M.A. NOHATTO ◽

R. MANICA-BERTO

Keyword(s):

Oxidative Damage ◽

Competitive Ability ◽

Cellular Damage ◽

Total Phenolic ◽

Total Phenolic Compounds ◽

Replacement Series ◽

Randomized Design ◽

Phenological Changes ◽

Activity Of Enzymes ◽

Completely Randomized Design

ABSTRACT Herbicide resistance can cause biochemical, physiological, morphological and phenological changes in weeds, altering their competitive ability against crops. The aim of the study was to assess physiological changes and cellular damage in susceptible and resistant biotypes of ryegrass and soybeans under competition. Three experiments were conducted in a greenhouse using a completely randomized design with four replications performed in a replacement series. The ratios of soybean and to susceptible (experiment 1) and resistant ryegrass (experiment 2) and of susceptible to resistant (experiment 3) ryegrass were 100:0, 75:25, 50:50, 25:75 and 0:100. Forty days after the emergence of the soybean crop and 60 days after the emergence of the ryegrass plants, the leaves of the competing plants were collected. The following variables were assessed: the levels of carotenoids, chlorophylls and total phenolic compounds; amount of hydrogen peroxide; degrees of lipid peroxidation and electrolyte leakage; and activity of enzymes catalase, superoxide dismutase and ascorbate peroxidase. The production of phenols and increased oxidative damage due to interspecies competition with ryegrass was, in general, observed in the soybeans; the ryegrass biotypes, susceptible and resistant to glyphosate, coexisting with soybean have generally higher oxidative damage due to intraspecific competition; since when these biotypes coexist not present modifications of these parameters.

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