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 Growth of the crabgrass species Digitaria ciliaris and Digitaria nuda

2012 ◽  
Vol 30 (2) ◽  
pp. 317-325 ◽  
Author(s):  
R.C. Souza ◽  
A.C. Dias ◽  
M.R.A. Figueiredo ◽  
F.E.B. Obara ◽  
P.J Christoffoleti
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Dry Matter ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Leaf Number ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth

The aim of this research paper was to compare the growth of D. ciliaris and D. nuda crabgrass species under non-competitive conditions. To this end, two experiments were conducted, one from March - July 2010 and the other from February - June 2011. The experimental design of both trials was completely randomized making a factorial (2 seasons x 2 species crabgrass x 12 evaluation periods) with four replications. Assessments began at 15 days after sowing (DAS), and repeated weekly until 92 DAS. The variables evaluated were total dry matter (roots+leaves+stems), leaf area, leaf number and tiller. The results were submitted to analysis of variance and the absolute growth rate, relative growth rate and leaf area ratio were calculated using the means, which were adjusted regression models. The crabgrass species were significantly different in leaf area, leaf number, tiller number and dry matter per plant. D. ciliaris for all variables was statistically higher than D. nuda. Regarding the speed at which the growth of the species occurred, the absolute growth rate and relative growth rate of D. ciliaris was also greater than D. nuda. In addition, D. ciliaris also had a lower leaf area ratio indicating greater efficiency in converting light energy into carbohydrates. It can be concluded that D. ciliaris has a higher growth rate in conditions where there is no limitation of nutrients and water availability in relation to D. nuda, mainly due to D. ciliaris have greater leaf area, number of leaves and dry matter accumulation per plant.

scholarly journals DIFFERENT SHADING NETS IN ESCAROLE GROWTH

2017 ◽  
Vol 26 (4) ◽  
pp. 584-595
Author(s):  
Daniela Meira ◽  
Daniele Cristina Fontana ◽  
Carla Janaina Werner ◽  
Thais Pollon Zanatta ◽  
Patricia Brezolin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Block Design ◽  
Weight Ratio ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Biological Productivity ◽  
Area Index ◽  
Absolute Growth Rate ◽  
Absolute Growth

The aim of work was to verify the effect of different shading levels in escarole crop, during summer in the northwest of Rio Grande do Sul. The experiment was conducted at the Federal University of Santa Maria, Frederico Westphalen RS Campus, in 2015 with Escarola Lisa escarole cultivar. The experimental design was a randomized complete block design with three shading levels (0%, 30%, 50%), with six replications. Growth evaluation were performed in destructive manner every seven days, from transplant to harvest point. From the information obtained, traits were determined: leaf area, leaf area index, leaf area ratio, specific leaf area, leaf weight ratio, biological productivity, absolute growth rate, relative growth rate, net assimilation rate. The data obtained were analyzed by the statistical program Genes, the Tukey test at 5% of error probability. The shading level 30% provided greater leaf area, higher biological productivity and absolute growth rate. However, the leaf area ratio was higher when shading level 50% was tested. However, it can be said that the shading levels favor growth of escarole crop.

scholarly journals Growth of canola hybrids resistant and sensitive to herbicides

2020 ◽  
Vol 41 (6supl2) ◽  
pp. 2911-2922
Author(s):  
Miria Rosa Durigon ◽  
◽  
Joanei Cechin ◽  
Franciele Mariani ◽  
Gerarda Beatriz da Silva Pinto ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Dry Matter ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Net Assimilation

Plant growth analysis is useful for determining adequate management practices and exploring the maximum yield potential of cultivars or hybrids. Canola hybrids with resistance to herbicides have been studied and registered for Brazilian conditions, as they improve weed management in canola crops. This study evaluated the growth of canola hybrids resistant to triazine or imidazolinone herbicides compared to a sensitive hybrid. The experiment was conducted using a completely randomized design, with four replications, in a bifactorial scheme using three hybrids and six sampling times. The canola hybrids used were Hyola 571CL (resistant to imidazolinones), Hyola 555TT (resistant to triazines), and Hyola 61 (sensitive to both herbicides). Height, leaf area, and dry matter of roots, leaves, stems, and shoots of the plants were evaluated at 14, 28, 42, 56, 70, and 119 days after emergence (DAE). The physiological indices absolute growth rate, leaf area ratio, specific leaf area, and net assimilation rate were calculated, and yield indices evaluated. Compared to Hyola 61, the Hyola 555TT hybrid showed lower values of leaf dry matter at 70 DAE, absolute growth rate up to 56 DAE, and net assimilation rate at 14 and 28 DAE, and a higher leaf area ratio at 56 DAE, whereas the hybrid Hyola 571CL presented lower leaf area and lower leaf dry matter at 70 DAE. At flowering, compared to Hyola 61, the hybrid Hyola 571CL presents lower leaf area, and the hybrids Hyola 555TT and Hyola 571CL have lower leaf dry matter accumulation. Differences in the growth of canola hybrids Hyola 555TT, Hyola 571CL and Hyola 61 do not cause differences in their grain yield.

scholarly journals Analysis of cassava growth at different harvest times and planting densities

2019 ◽  
Vol 40 (1) ◽  
pp. 113
Author(s):  
Eli Carlos de Oliveira ◽  
Luiz Henrique Campos de Almeida ◽  
Claudemir Zucareli ◽  
Teresa Losada Valle ◽  
José Roberto Pinto de Souza ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Dry Mass ◽  
Area Ratio ◽  
Plant Population ◽  
Leaf Area Ratio ◽  
Primary Data ◽  
Population Densities ◽  
Relative Growth

Vegetative canopy architecture, and plant population density, has a direct influence on the growth and production of crops. The objective of this study was to evaluate the growth of four cassava cultivars of contrasting canopies, in four population densities, during two vegetative cycles. A randomized complete block design was used in a subdivided plot scheme, with two replications, with the population densities in the plots and harvesting times in the subplots. ‘Branca de Santa Catarina’ (BSC), ‘IAC 13’, ‘IAC 14-18’ and ‘Fibra’ were collected every four months, beginning at 120 and ending at 720 days after planting (DAP). Primary data on dry matter and leaf area were calculated. The total dry mass (Wt), leaf area ratio (La), leaf area index (L), relative growth rate (Rw), and net assimilation rate (Ea) were calculated based on the primary data. All cultivars accumulated more total dry mass (Wt) at lower planting densities. The plants reached a higher leaf area ratio (La) 120 days after planting. In the second vegetative cycle, the four cultivars, independently of the population, presented a reduction of assimilate translocation to the leaves. Relative growth rate (Rw) of the cultivars varied strongly with the plant population only in the second cycle. ‘IAC 14-18’ showed greater dependence on spacing, and ‘Fibra’ less dependence. Growth (Rw) and assimilatory (Ea) rates decreased at the end of the first cycle, then increased slowly until the end of the second cycle of vegetation.

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.

Growth and Developmental Responses of Perennial Ryegrass Grown at Constant Temperature. I. Influence of Light and Temperature on Growth and Net Assimilation

1981 ◽  
Vol 8 (2) ◽  
pp. 181 ◽  
Author(s):  
WF Hunt ◽  
G Halligan
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Perennial Ryegrass ◽  
Response Curve ◽  
Maximum Growth ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Exponential Growth Phase ◽  
Response Curves ◽  
Net Assimilation

Perennial ryegrass (Lolium perenne L. cv. 'Grasslands Ruanui') plants were grown spaced in nutrient golution under six levels of irradiance at six constant temperatures (7-33°C) to provide growth response curves to light and temperature over a range of growth conditions. Measurements were restricted to the exponential growth phase. Plants showed saturation-type growth kinetics with irradiance but the shape of the light response curve was temperature dependent and, conversely, the shape of the temperature response curve was irradiance dependent. Growth analysis revealed that, at 7, 10, 17 and 20°C, changes in leaf area ratio compensated for changes in net assimilation rate over a range in irradiance for which growth rate was maintained near maximum. At 30 and 33°C, the compensating effect of changes in leaf area ratio was insufficient to maintain near maximum growth at intermediate irradiances. Ontogenetic drifts in specific leaf area and leaf area ratio were compensated for by changes in net assimilation, so that relative growth rate remained constant. The maximum growth at 20°C resulted from a greater partitioning of dry weight to leaf than at lower temperatures, as well as higher net assimilation than at all other temperatures.

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.

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