scholarly journals RELATIVE COMPETITIVENESS OF GOOSEGRASS BIOTYPES AND SOYBEAN CROPS

2017 ◽  
Vol 30 (2) ◽  
pp. 271-277 ◽  
Author(s):  
JADER JOB FRANCO ◽  
DIRCEU AGOSTINETTO ◽  
ANA CLAUDIA LANGARO ◽  
LAIS TESSARI PERBONI ◽  
LEANDRO VARGAS
Keyword(s):  
Competitive Ability ◽  
Total Population ◽  
Dry Weight ◽  
Replacement Series ◽  
Genetically Modified Soybean ◽  
Eleusine Indica ◽  
Soybean Crop ◽  
Shoot Dry Weight ◽  
Control Failure ◽  
Level Resistance

ABSTRACT The goosegrass (Eleusine indica (L.) Gaertn) is an annual plant that has a low-level resistance to glyphosate (LLRG), resulting in control failure in genetically modified soybean crops for resistance to this herbicide. Alleles related to resistance may cause changes in the plant biotype, such as inferior competitive ability. Thus, the objective of this work was to evaluated the competitive ability of soybean crops and susceptible and resistant (LLRG) goosegrass biotypes. Replacement series experiments were conducted with soybean crops and goosegrass biotypes. The ratios of soybean to susceptible or resistant (LLRG) goosegrass plants were 100:0, 75:25, 50:50, 25:75 and 0:100, with a total population of 481 plants m-2. The leaf area, plant height and shoot dry weight were evaluated at 40 days after emergence of the soybean crops and weeds. The soybean crop had superior competitive ability to the susceptible and resistant (LLRG) goosegrass biotypes. The soybean crop showed similar competitive ability in both competitions, either with the susceptible or resistant (LLRG) goosegrass biotypes. The intraspecific competition was more harmful to the soybean crop, while the interspecific competition caused greater damage to the goosegrass biotypes competing with the soybean crop.

scholarly journals Interference of Sorghum sudanense and Eleucine indica in the soybean and corn cultivation

2014 ◽  
Vol 32 (1) ◽  
pp. 19-30 ◽  
Author(s):  
M.A. Rizzardi ◽  
A.C.D. Wandscheer
Keyword(s):  
Experimental Design ◽  
Competitive Analysis ◽  
Dry Weight ◽  
Experimental Unit ◽  
Replacement Series ◽  
Numerous Species ◽  
Eleusine Indica ◽  
Shoot Dry Weight ◽  
Sorghum Sudanense ◽  
Corn Plants

The natural infestations are composed of numerous species that compete for environmental resources such as water, light, nutrients and space. The objective of this study was to evaluate the interference of mixed infestations Sorghum sudanense (sudangrass) and Eleusine indica (goosegrass) in the presence of soybean and corn. The experimental design was completely randomized with four replications and the experimental units consisted of plastic pots with a volume capacity of 8 L. The treatments were associations of plants S. sudanense and E. indica in the proportions 8:0, 6:2, 4:4,2:6 and 0:8, respectively, corresponding to 100, 75, 50, 25 and 0% S. sudanense and the reverse for E. indica. In all treatments remained constant four soybean or corn plants per experimental unit. The variables analyzed in the weeds were shoot dry weight, root, total and height of plants. The competitive analysis was accomplished through diagrams applied to replacement series experiment and indexes of competiveness. The results indicated that E. indica was more competitive than S. sudanense in mixed infestations with corn. Rather, S. sudanense was more competitive than E. indica, in mixed infestations with soybean, demonstrating differences in competitiveness among the weeds.

Growth, fecundity, and competition between aryloxyphenoxypropionate-resistant and -susceptible Asia Minor bluegrass (Polypogon fugax)

Weed Science ◽  
2019 ◽  
Vol 67 (05) ◽  
pp. 546-551 ◽  
Author(s):  
Wei Tang ◽  
Jie Chen ◽  
Xiaoyue Yu ◽  
Jianping Zhang ◽  
Yongliang Lu
Keyword(s):  
Competitive Ability ◽  
Dry Weight ◽  
Growth Cycle ◽  
Asia Minor ◽  
Flowering Stage ◽  
Replacement Series ◽  
Shoot Dry Weight ◽  
Winter Crops ◽  
Grass Weed ◽  
Screen House

AbstractAsia Minor bluegrass (Polypogon fugax Nees ex Steud.) is a problem grass weed of winter crops in China, where a population has become resistant to aryloxyphenoxypropionate (APP) herbicides. The mechanism of resistance is due to an Ile-2041-Asn mutation of the ACCase gene. Screen house experiments were conducted to study the growth, fecundity characteristics, and competitive ability of this aryloxyphenoxypropionate-resistant (APP-R) biotype compared with a susceptible (APP-S) biotype. When grown under noncompetitive conditions, the APP-R P. fugax developed more rapidly than the APP-S plants, with earlier tiller and panicle emergence and seed shedding; the APP-R P. fugax set seeds nearly 12 d earlier than the APP-S biotype. APP-R and APP-S biotypes had similar aboveground dry weight before the flowering stage. Fecundity of the APP-R biotype was similar to the APP-S biotype (8.57 g seeds plant−1 and 0.17 g seeds panicle−1 versus 8.22 g seeds plant−1 and 0.13 g seeds panicle−1, respectively). Ultimately, the relatively slower-developing APP-S P. fugax had 50% more shoot dry weight than the APP-R plants. Relative competitiveness among the APP-R and APP-S P. fugax biotypes was investigated through replacement series experiments. No difference in competitive ability was measured between APP-R and APP-S biotypes on the basis of shoot dry weight before the tillering stage. These results indicate that there is no apparent fitness penalty for the APP-R P. fugax. The shorter growth cycle of APP-R with no apparent fitness penalty suggests that growers will need begin weed control earlier and possibly include vegetative crops with an even shorter growth cycle in their rotations.

scholarly journals Fitness Cost and Competitive Ability to Different Ploidy Levels in Ryegrass Genotypes

2019 ◽  
Vol 37 ◽  
Author(s):  
M.F. SCHMITZ ◽  
J. CECHIN ◽  
J.R. HENCKES ◽  
C. PIASECKI ◽  
D. AGOSTINETTO ◽  
...  
Keyword(s):  
Leaf Area ◽  
Competitive Ability ◽  
Dry Weight ◽  
Fitness Cost ◽  
Replacement Series ◽  
Ploidy Levels ◽  
Shoot Dry Weight ◽  
Seed Yield Components ◽  
Diploid Genotype ◽  
Intergenotypic Competition

ABSTRACT: The intergenotypic competition of tetraploid ryegrass with natural diploid population may be a tool to reduce the frequency of resistant individuals in an area. This study aimed to identify and compare the phenological development, fitness cost, and competitive ability between diploid and tetraploid ryegrass genotypes. Genotypes were grown in pots, and the morphological variables of genotype growth were assessed every 15 days up to 120 days after emergence to evaluate the fitness cost. Phenological development and seed yield components were measured in a single time together with the fitness cost. Competitive ability was determined in a replacement-series experiment with proportions of tetraploid and diploid ryegrass, in which the number of tillers, plant height, leaf area, and shoot dry weight were assessed at 50 days after emergence. The results of fitness cost showed that the number of tillers, leaf area, root dry weight, and the number of seeds were higher for tetraploid ryegrass, which presented a higher competitive ability than the diploid genotype regardless of the tested proportions. Tetraploid ryegrass may be useful for reducing the frequency of herbicide-resistant diploid ryegrass because of its higher competitive potential.

The relative competitiveness of atrazine susceptible and resistant populations of Chenopodium album and C. strictum

1981 ◽  
Vol 59 (5) ◽  
pp. 689-693 ◽  
Author(s):  
S. I. Warwick ◽  
L. Black
Keyword(s):  
Biomass Production ◽  
Aboveground Biomass ◽  
Competitive Ability ◽  
Chenopodium Album ◽  
Dry Weight ◽  
Replacement Series ◽  
Susceptible Population ◽  
Resistant Population ◽  
Reproductive Biomass ◽  
Susceptible Populations

The total aboveground biomass and reproductive dry weight of one atrazine resistant and one susceptible population from southern Ontario of each of two species of Chenopodium, C. album and C. strictum, were compared. The comparison was made between plants grown under both noncompetitive and competitive conditions. Results from a spaced noncompetitive trial provided evidence for: (1) greater total and reproductive biomass production and earlier flowering of resistant and susceptible populations of C. album as compared with both populations of C. strictum, (2) greater aboveground total and reproductive biomass production of the susceptible population of C. album as compared with the resistant population, and (3) greater total aboveground biomass production (but similar reproductive biomass) of the susceptible population of C. strictum as compared with the resistant population. Results from the competition trials (i.e., plants grown in a de Wit replacement series), provided evidence for inter- and intra-specific differences in competitive ability: (1) the susceptible population of C. album was found to be more competitive than the susceptible population of C. strictum, (2) the susceptible population of C. album was a superior competitor to the resistant population, and (3) the resistant and susceptible populations of C. strictum appeared to be equally competitive.

scholarly journals Relative Competitiveness Between Cultivated and Weedy Rice under Full and Low Light

2020 ◽  
Vol 38 ◽  
Author(s):  
C.E. SCHAEDLER ◽  
W. LUBIAN ◽  
P.C. LIMA ◽  
D.M. CHIAPINOTTO
Keyword(s):  
Plant Height ◽  
Dry Weight ◽  
Rice Cultivar ◽  
Weedy Rice ◽  
Cultivated Rice ◽  
Replacement Series ◽  
Low Light ◽  
Shoot Dry Weight ◽  
Randomized Design ◽  
Rice Monoculture

ABSTRACT: Cultivated and weedy rice biotypes exhibit morphophysiological variations under low light, affecting competition between plants. The aim of this study was to assess relative competitiveness between cultivated and weedy rice under full and low light. Three experiments were conducted in a greenhouse, using a completely randomized design with four repetitions. The treatments in the experiment I were arranged in additive series while in the experiments II and III treatments were arranged in replacement series. Experiments II and III were carried out concomitantly to assess coexistence between the rice cultivar and weedy rice. The treatments consisted of different plants proportions: 100:0 (cultivated rice monoculture), 75:25, 50:50, 25:75 and 0:100 (weedy rice monoculture), keeping the total plant population obtained in experiment I (240 plants m-2) constant. Experiment II was conducted with full solar radiation and III under 50% light. The variables analyzed were shoot dry weight and plant height, 35 days after emergence (DAE). Competition among plants was evaluated via graphs and by interpreting competition indices. Concerning shoot dry weight, mutual losses were recorded between competitors, whereas equal competition for resources was observed for plant height. Weedy rice was more competitive than cultivated rice regardless of the light environment assessed, indicating the need for integrated methods to control this weed.

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 Weed-Competitive Ability of Forage Maize Cultivars against Barnyardgrass

2020 ◽  
Vol 8 (1) ◽  
pp. 174
Author(s):  
Khawar Jabran
Keyword(s):  
Competitive Ability ◽  
Research Work ◽  
Dry Weight ◽  
Leaf Length ◽  
Fresh Weight ◽  
Forage Maize ◽  
Shoot Dry Weight ◽  
Maize Cultivars ◽  
Maize Plants ◽  
Leaf Dry Weight

Weed-competitive cultivars are desired in the wake of growing popularity of organic farming, environmental pollution and evolution of herbicide resistance in weeds. This research work evaluated the weed competitive ability of three forage maize cultivars (ADA-523, AGA and SASA-5) against the noxious weed barnyardgrass (Echinochloa crus-galli (L.) P.Beauv.). The study was conducted in spring 2018 and repeated in summer 2018. Results of this study showed that maize-barnyardgrass competition significantly decreased the growth of forage maize plants. For instance, barnyardgrass decreased the maize plant height by 11.9-16.9%, leaf length by 13.3-20.2%, leaf width by 20.2-27.4%, and number of leaves by 14.3-25.0%. Fresh and dry weights of maize plants were also significantly decreased as a result of weed-crop competition. Barnyardgrass decreased the shoot fresh weight (30.7-60.6%), shoot dry weight (33.3-52.2%), leaf fresh weight (33.4-56.5%) and leaf dry weight (31.9-50.0%) of the maize plants. An interactive effect of weed × maize cultivars was found non-significant. Forage maize cultivars also varied occasionally for their traits. Nevertheless, ADA-523 had a higher plant height, leaf length, leaf width, leaf fresh weight and leaf dry weight than the cultivars AGA and SASA-5. On the other hand, the cultivar SASA-5 had a higher shoot fresh weight, shoot dry weight and root fresh weight than the other cultivars in the study. This research work concluded that the forage maize cultivars in the study did not vary for the weed-competitive ability. Further, barnyardgrass-maize competition could decrease the growth and development of the maize cultivars.

scholarly journals Adaptive value of ryegrass biotypes with low-level resistance and susceptible to the herbicide fluazifop and competitive ability with the wheat culture

2013 ◽  
Vol 31 (4) ◽  
pp. 875-885 ◽  
Author(s):  
D.S. Fraga ◽  
D. Agostinetto ◽  
L. Vargas ◽  
M.A. Nohatto ◽  
L. Thürmer ◽  
...  
Keyword(s):  
Competitive Ability ◽  
Yield Loss ◽  
Wheat Cultivar ◽  
Fitness Cost ◽  
Wheat Crop ◽  
Replacement Series ◽  
Low Level ◽  
Adaptive Value ◽  
Dry Biomass ◽  
Level Resistance

Ryegrass is the main weed in wheat crop, causing yield loss due to competition by environmental resources. The objectives of this study were to estimate the fitness cost of ryegrass biotypes with low-level resistance and susceptible to fluazifop and to investigate the relative competitive ability of these biotypes between themselves and against the crop. Thus, fitness cost and competitive ability experiments were conducted under greenhouse conditions. For the fitness cost experiments, the low-level resistant ryegrass biotypes and those susceptible to fluazifop were used. For competitive ability, the treatments were arranged in a replacement series, with five proportions of the wheat cultivar FUNDACEP Horizonte and the low-level resistant and susceptible ryegrass biotypes 100:0, 75:25, 50:50, 25:75 and 0:100. Competitive analysis was carried out through diagrams applied to the replacement experiments and use of relative competitiveness indices. Variables evaluated were plant height, in the fitness cost experiment, and leaf area and shoot dry biomass in both experiments. The ryegrass biotypes show overall similar fitness cost and competitive ability. The wheat cultivar FUNDACEP Horizonte is superior in competitive ability to the ryegrass biotype with low-level resistance and equivalent to the susceptible biotype.

The competitive ability of wheat (Triticum aestivum) compared to rigid ryegrass (Lolium rigidum) and cowcockle (Vaccaria hispanica)

Weed Science ◽  
1997 ◽  
Vol 45 (4) ◽  
pp. 481-487 ◽  
Author(s):  
Abbes Tanji ◽  
Robert L. Zimdahl ◽  
Philip Westra
Keyword(s):  
Competitive Ability ◽  
Field Experiments ◽  
Wheat Plant ◽  
Dry Weight ◽  
Shoot Dry Weight ◽  
Semiarid Areas ◽  
Absolute Growth ◽  
Rigid Ryegrass ◽  
Growth Analyses ◽  
Competition Growth

Greenhouse and field experiments were conducted to study competition between wheat and rigid ryegrass or between wheat and cowcockle using additive series and growth analysis. Wheat was the dominant competitor with either weed. One wheat plant was as competitive as 1 1 or 19 rigid ryegrass plants in greenhouse and field experiments, respectively. One wheat plant was as competitive as three to 24 cowcockle plants, depending on environmental conditions. Dry weight of roots, leaves, stems, and spikes or capsules responded similarly to the effects of competition between wheat and rigid ryegrass or cowcockle. Shoot dry weight was the easiest, fastest, and least expensive component to measure competition. Growth analyses of individual plants showed that wheat had a greater leaf area, shoot and root dry weight, and absolute growth rate than rigid ryegrass or cowcockle, particularly early in the season. A range of 120 to 240 wheat plants m−2can minimize rigid ryegrass or cowcockle competition and achieve an acceptable grain yield in semiarid areas in Morocco.

scholarly journals Competitive ability of canola (Brassica napus var. oleifera) hybrids with black oat (Avena strigosa) in a subtropical environment

2021 ◽  
Vol 53 (2) ◽  
pp. 119-131
Author(s):  
Leandro Galon ◽  
Germani Concenço ◽  
Luciane Renata Agazzi ◽  
Felipe Nonemacher ◽  
Thais Stradioto Melo ◽  
...  
Keyword(s):  
Competitive Ability ◽  
Total Population ◽  
Co2 Concentration ◽  
Replacement Series ◽  
Data Set ◽  
Avena Strigosa ◽  
Internal Co2 ◽  
Infrared Gas Analyzer ◽  
Better Than ◽  
Subtropical Environment

The objective of this study was to assess the competitive ability of canola (Brassicanapus var. oleifera) hybrids in competition with black oat (Avena strigosa) in a subtropical environment. The experiments were conducted in a greenhouse where canola hybrids ‘Hyola 61,’ ‘Hyola 76,’ ‘Hyola 433,’ and ‘Hyola 571’ were tested individually for their competitive performance with black oat. The plant proportion between black oat and the canola hybrid was changed (100%:0%; 75%:25%; 50%:50%; 25%:75%; and 0%:100%) while keeping the total population of plants constant (20 plants plot‑1). Photosynthesis rate (μmol m-2 s-1), internal CO2 concentration (μmol mol-1), and  transpiration rate (mol H2O m-2 s-1) were assessed using an infrared gas analyzer 55 days after emergence. Leaf area (m2 m-2) and dry matter (g m-2) were also assessed on the same day. The data set was analyzed by the replacement series method for competition studies. There was evidence of intense competition between canola and black oat, independent of plant proportion. The competitive ability of canola was distinct among hybrids; Hyola 571 performed better than the others in the competition against black oat. Choosing the most competitive hybrid, such as Hyola 571, helps maintain high canola grain yield levels in areas infested with black oat. Highlights: There is difference in competition among canola hybrids against black oat; Hyola 571 performed better in the competition; Preference should be given for most competitive canola genotypes against weeds, and weed control should be carried out early in the critical period of interference; Aggressiveness is the most preponderant parameter in determining canola genotypes with superior ability in competition against weeds.

Sign in / Sign up

Export Citation Format

Share Document