scholarly journals RELATIVE COMPETITIVENESS BETWEEN MAIZE HYBRIDS AND WILD POINSETTIA

2021 ◽  
Vol 34 (2) ◽  
pp. 298-309
Author(s):  
LEANDRO GALON ◽  
RICARDO LUIS GABIATTI ◽  
FELIPE JOSÉ MENIN BASSO ◽  
ANDRÉ LUIZ RADÜNZ ◽  
FRANCISCO WILSON REICHERT JÚNIOR ◽  
...  
Keyword(s):  
Interspecific Competition ◽  
Leaf Area ◽  
Intraspecific Competition ◽  
Competitive Ability ◽  
Dry Mass ◽  
Plant Population ◽  
Grain Production ◽  
Replacement Series ◽  
Maize Hybrids ◽  
Chlorophyll Index

ABSTRACT Maize is one of the main cereals cultivated worldwide and wild poinsettia is among the weeds that cause damage in grain production. The objective of this study was to evaluate the relative competitive ability of maize hybrids in the presence of a wild poinsettia biotype through experiments in replacement series. In preliminary experiments, it was determined the plant population in which the dry mass becomes constant. For the maize hybrids ‘Agroeste’, ‘Morgan’, ‘Nidera’, and ‘Velox’, as well as the wild poinsettia, the population was 20 individuals vase-1. Subsequently, experiments were carried out in replacement series in different combinations of species that varied the relative proportions (100:0, 75:25, 50:50, 25:75, and 0:100%). The analysis of the species' competitiveness was carried out using diagrams applied to the replacement experiments and by the relative competitiveness indexes. The height (PH), chlorophyll index (CI), leaf area (LA), and the shoot dry mass (DM) of the plants were evaluated 50 days after emergence. There was competition between the maize hybrids and the wild poinsettia; both were negatively affected, regardless of the proportion of plants, causing reductions in the species' PH, CI, LA, and DM. The competition between maize and wild poinsettia occurs for the same resources in the environment, and interspecific competition caused greater damage to maize and wild poinsettia than intraspecific competition. In general, it was observed that only the hybrids ‘Nidera’ and ‘Velox’ were more competitive than the wild poinsettia.

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

2014 ◽  
Vol 32 (1) ◽  
pp. 189-196 ◽  
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.

scholarly journals COMPETITIVE RELATIVE ABILITY OF BARLEY CULTIVARS IN INTERACTION WITH TURNIP

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
L. GALON ◽  
L.R. AGAZZI ◽  
F. NONEMACHER ◽  
F.J.M. BASSO ◽  
F.L. WINTER ◽  
...  
Keyword(s):  
Leaf Area ◽  
Competitive Analysis ◽  
Intraspecific Competition ◽  
Growth And Development ◽  
Aerial Part ◽  
Competitive Ability ◽  
Dry Mass ◽  
Replacement Series ◽  
Barley Cultivars ◽  
Relative Ability

ABSTRACT Among the weeds that cause interference with the growth and development of barley the turnip stands out, especially by the high competitive ability for the resources available in the environment. The research objective with the study was to evaluate the competitive ability of barley cultivars to live with a turnip biotype. Experiments were installed in a greenhouse, in the experimental outlining of randomized blocks designed with four repetitions. The treatments were arranged in replacement series, consisting of proportions of barley plants and turnip: 100: 0, 75:25, 50:50, 25:75 and 0: 100% which was equivalent to 20: 0, 15: 5, 10:10, 5:15 and 0:20 plants per pot. The barley was represented by BRS Cauê, BRS Elis and MN 610 and the competitor by turnip. The competitive analysis was made through diagrams applied in replacement experiments, among with use of relative competitiveness indices. The leaf area (AF) and the dry mass of the aerial part (MS) were evaluated at 50 days after the emergence of the species. The results show that there was competition between barley varieties with the turnip with mutual damage to the species involved in the community. Turnip negatively modified the AF and the MS of BRS Cauê, MN 610 and BRS Elis demonstrating higher competitive ability for the means of the resources. The interspecific competition causes greater damage to the AF and the MS species than the intraspecific competition. Thus, the turnip control is recommended the turnip control even when present at low densities of plants infesting the barley.

scholarly journals COMPETITIVE ABILITY OF CANOLA HYBRIDS WITH WEEDS

2015 ◽  
Vol 33 (3) ◽  
pp. 413-423 ◽  
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.

Competitive Ability of Wild Oats (Avena fatua) and Barley (Hordeum vulgare)

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 558-563 ◽  
Author(s):  
Claudio M. Dunan ◽  
Robert L. Zimdahl
Keyword(s):  
Growth Rate ◽  
Interspecific Competition ◽  
Leaf Area ◽  
Intraspecific Competition ◽  
Competitive Ability ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Field Conditions ◽  
Shoot Biomass ◽  
Wild Oats

Replacement series and growth analysis experiments under greenhouse and field conditions quantified and explained the competitive ability of wild oats and barley. Barley was a stronger competitor than wild oats under greenhouse and field conditions. The reciprocal yield approach showed that barley's intraspecific competition was 7.3 times greater than its interspecific competition with wild oats when calculated on a dry weight per plant basis. When leaf area per plant was the yield variable, barley's intraspecific competition was only 2.4 times greater than its interspecific competition. The difference was explained by wild oats' higher leaf area ratio. Barley had a greater leaf area, root and shoot biomass, absolute growth rate, and shoot-root ratio than wild oats, but wild oats' leaf area ratio was always higher. No differences were detected in relative growth rate and net assimilation rate.

scholarly journals Competition of maize hybrids with alexandergrass (Urochloa plantaginea)

2019 ◽  
pp. 1447-1455
Author(s):  
Fernando Frandoloso ◽  
Leandro Galon ◽  
Ricardo Luis Gabiatti ◽  
Felipe Bianchessi ◽  
Cinthia Maethê Holz ◽  
...  
Keyword(s):  
Interspecific Competition ◽  
Block Design ◽  
Dry Mass ◽  
Separate Experiment ◽  
Experimental Unit ◽  
Replacement Series ◽  
Maize Hybrids ◽  
Randomized Block Design ◽  
Set Up ◽  
Sun Light

Maize is one of the world's major cereals, and alexandergrass is the most damaging weed in the crop. The objective of this work was to evaluate the relative competitive ability of maize hybrids in the presence of alexandergrass through replacement series experiments. The experiments were set up in a complete randomized block design, with four replications. Firstly, for the maize hybrids as well as for the alexandergrass, the plant population was determined in which the final production becomes constant. were composed of plastic pots with a capacity of 8 dm3, and in each experimental unit was placed in the proportion corresponding to each treatment (100: 00, 75:25, 50:50, 25:75 and 0: 100) in each experimental unit, the species competing or not between them. For each hybrid, a separate experiment was considered with the objective of evaluating intra and interspecific competition. The analysis of the competitiveness of the species was carried out through diagrams applied to the replacement experiments and by the relative competitiveness indexes. At 50 days after the emergence of the maize the leaf area (LA) and the dry mass of the aerial part (DM) of the plants were checked. The relative competition was occured among the weed and each maize hybrid, being negatively affected for both of species, independently of the proportion of weed causing reductions in LA and DM of the maize. Interspecific competition causes less damage to LA and DM of species than intraspecific competition. There is basically competition for the same environment resources (water, CO2, sun light and nutrients) between maize and alexandergrass, being the crop more competitive than the weed.

scholarly journals Competitive Ability of Canola Hybrids Resistant and Susceptible to Herbicides

2019 ◽  
Vol 37 ◽  
Author(s):  
M.R. DURIGON ◽  
F. MARIANI ◽  
J. CECHIN ◽  
A.S. CAMERA ◽  
L. VARGAS ◽  
...  
Keyword(s):  
Interspecific Competition ◽  
Leaf Area ◽  
Intraspecific Competition ◽  
Aerial Part ◽  
Dry Matter ◽  
Competitive Ability ◽  
Crop Growth ◽  
Randomized Design ◽  
Completely Randomized Design

ABSTRACT: This work aimed to compare the competitive ability of canola hybrids susceptible (conventional) or resistant to triazine or imidazolinone group herbicides, with turnip. The experiments were conducted in greenhouse, in a completely randomized design, with four replicates. The hybrids Hyola 571CL (resistant to imidazolinone), Hyola 555TT (resistant to triazine), and Hyola 61 (conventional) were used. The treatments consisted of ratios (100:0; 75:25; 50:50; 25:75; 0:100%) of canola and turnip plants. The evaluation was performed 44 days after emergence, determining the leaf área (AF), dry matter of aerial part (MSPA), and stature (EST) of the plants. The competitiveness analysis was performed through diagrams and interpretation of the competitiveness indexes. For the canola hybrids, the competition occurred by the same mean resources. There was damage to the crop growth in competition with the turnip. The turnip was not benefited only when in competition with Hyola 571CL hybrid, for the EST variable, and with the conventional canola, for the variable AF. There was significance for the competitiveness indexes, demonstrating that turnip is more competitive then the crop. Greater AF, MSPA, and EST occurred for canola plants in the smallest proportions of turnip and, for turnip plants, in the largest proportions of canola. The ability to compete with turnip is similar among hybrids, with injury to the crop and benefit to the weed, when competing. Interspecific competition is more damaging to canola hybrids; and intraspecific competition is more damaging to turnip.

scholarly journals Competitiveness of alexandergrass or Bengal dayflower with soybean

2010 ◽  
Vol 28 (3) ◽  
pp. 515-522 ◽  
Author(s):  
A.C.R. Dias ◽  
S.J.P. Carvalho ◽  
L.W. Marcolini ◽  
M.S.C. Melo ◽  
P.J. Christoffoleti
Keyword(s):  
Competitive Ability ◽  
Dry Mass ◽  
Total Density ◽  
Weed Species ◽  
Replacement Series ◽  
Commelina Benghalensis ◽  
Randomized Design ◽  
Full Flowering ◽  
Completely Randomized Design ◽  
Soybean Plants

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.

scholarly journals Initial growth and competitive ability of yellow nutsedge and irrigated rice

2013 ◽  
Vol 31 (4) ◽  
pp. 813-821 ◽  
Author(s):  
N.R. Westendorff ◽  
D. Agostinetto ◽  
A.R. Ulguim ◽  
A.C. Langaro ◽  
L. Thürmer
Keyword(s):  
Leaf Area ◽  
Competitive Ability ◽  
Growth Cycle ◽  
Rice Crop ◽  
Initial Growth ◽  
Rice Cultivars ◽  
Replacement Series ◽  
Irrigated Rice ◽  
Yellow Nutsedge ◽  
Dry Biomass

Weeds cause significant reduction in the irrigated rice crop yield. Cyperus esculentus (yellow nutsedge) is adapted to irrigate environment. Information on the competitive ability of the weed to the culture, and their environmental adaptation, are scarce. In this study, we sought to determine the initial growth and competitive ability of yellow nutsedge and irrigated rice, as a function of cultivar growth cycle. Initial growth and competition studies were conducted in a randomized complete design in a greenhouse in the agricultural year 2010/11. For the initial growth study, the treatments consisted of a factorial combination of a biotype of yellow nutsedge and two rice cultivars in the function of the vegetative cycle (BRS Querência: early cycle - IRGA 424: intermediate cycle) and six evaluation times (10, 20, 30, 40, 50, and 60 days after emergence). Were evaluated: plant height, leaf area, aboveground dry biomass and root dry biomass. In the competitive ability study in the replacement series, the cultivar BRS Querência (early cycle) and yellow nutsedge were utilized and tested in different proportions of competition (100:0, 75:25, 50:50, 25:75, and 0:100). Were evaluated leaf area and aboveground dry biomass. In general, rice cultivars have an adaptive value equivalent to yellow nutsedge. IRGA 424 cultivar has less height than weed, becoming the weed control more important in this cultivar. For rice crop, intraspecific competition is more important, whereas for the weed, interspecific competition is the most pronounced.

scholarly journals Soybeans Competitiveness with Morning Glory

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.

Studies on mixtures of maize and beans (Phaseolus vulgaris) with particular reference to plant population

1972 ◽  
Vol 79 (3) ◽  
pp. 517-529 ◽  
Author(s):  
R. W. Willey ◽  
D. S. O. Osiru
Keyword(s):  
Competitive Ability ◽  
Maximum Yield ◽  
Plant Population ◽  
Population Pressure ◽  
Nitrogen Transfer ◽  
Replacement Series ◽  
Plant Populations ◽  
Intensive Farming ◽  
Optimum Proportion ◽  
High Level

SUMMARYTwo experiments are described in which the possible yield benefits of mixing maize and beans were examined under intensive farming conditions. A ‘replacement series’ of pure maize, two-thirds maize/one-third beans, one-third maize/two-thirds beans and pure beans was used at four plant populations. A high level of nitrogen was applied on the maize to eliminate the effects of nitrogen transfer from the beans.Yields of the mixtures were up to 38% higher than could be achieved by growing the crops separately. It is concluded that this occurred because the mixtures achieved a greater utilization of environmental resources; it is suggested that, because of the marked height differences of the two crops, an increased utilization of light was probably a major contributing factor. The need for high populations in mixtures is indicated, partly because the largest yield increases were achieved at high populations and partly because the mixtures required a higher population pressure to produce their maximum yield.The maize was found to have the higher relative competitive ability, and this increased with increase in plant population pressure. It is suggested that this was probably due to the shading effect which the maize had on the beans. The effects of a change in relative competitive abilities, or in relative selling prices, on the optimum proportion of two species in a mixture are also considered.

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