scholarly journals Weed Community in a Conventionally-Grown Olive Orchard Vs. Weed Community in Consociation with Pyrethrum (Tanacetum cinerariifolium (Trevir.) Sch. Bip.)

Poljoprivreda ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 30-36
Author(s):  
Edita Štefanić ◽  
◽  
Vesna Kovačević ◽  
Lea Jakovljević ◽  
Urška Kosić ◽  
...  
Keyword(s):  
Cover Crop ◽  
Vascular Plants ◽  
Floristic Composition ◽  
Community Diversity ◽  
Weed Species ◽  
Olive Orchard ◽  
Weed Communities ◽  
Tanacetum Cinerariifolium ◽  
The One ◽  
Experimental Plots

On the experimental plots of the Institute of Agriculture and Tourism in Poreč, weed communities were analyzed in a conventionally‐grown olive orchard and in consociation with pyrethrum. Phytocenological surveys were conducted in March, June, and September using the Braun-Blanquet Cover Abundance Scale. Altogether, 54 species of vascular plants were recognized in both orchards. However, in a conventionally‐grown olive orchard, 27 were identified, whereas 42 weed species were identified in consociation with pyrethrum. Only 15 weeds were common to both orchards. Between both olive orchards, significant differences existed regarding the floristic and community diversity metrics. In consociation with pyrethrum as a cover crop, olive orchard had a more stable weed community during the season, while two weed species, Mercurialis annuua L. and Medicago arabica (L.) Huds., dominated in a conventionally‐grown orchard in the fall. The weed communities in both orchards significantly differ considering the appearance season (spring, summer, and fall). An autumnal weed community in a conventionally‐grown olive orchard was more diverse, more abundant, and with a more distinct floristic composition than a weed community in the spring and summer periods. However, an olive‐orchard weed community in consociation with pyrethrum also differed regarding the season, but a Canonical Correspondence Analysis (CCA) demonstrated a clear separation of a more diverse estival weed community than the one observed in the spring and summer.

scholarly journals Weed Phytosociological and Floristic Survey in Agricultural Areas of Southwestern Goiás Region

2016 ◽  
Vol 34 (1) ◽  
pp. 65-80 ◽  
Author(s):  
SANTOS W.F. ◽  
PROCÓPIO S.O. ◽  
SILVA A.G. ◽  
FERNANDES M.F. ◽  
BARROSO A.L.L.
Keyword(s):  
Cropping Systems ◽  
Floristic Composition ◽  
Sampling Period ◽  
Weed Species ◽  
Floristic Survey ◽  
Commelina Benghalensis ◽  
Number Of Species ◽  
West Region ◽  
Weed Communities ◽  
Agricultural Areas

The use of the Roundup Ready(r) technology and the cultivation of a second crop influence the floristic composition of weed communities in Brazilian Central-West region cropping systems. This study has aimed to diagnose the dominant weed species in southwestern Goiás in areas of genetically-modified and conventional soybeans, using phytosociological and floristic surveys. Weed sampling was obtained by collecting all the plants present within a 0.5 m hollow frame, randomly thrown 20 times in each of thirty-five agricultural areas in the 2012/2013 harvest. Field survey was carried out in three periods: before desiccation for soybean sowing, before postemergence herbicide in soybean first application and before postemergence herbicide application in late harvest. A total of 525 m2 was inventoried and 3,219 weeds were collected, which included 79 species, 58 genera and 28 families. Families Poaceae, Asteraceae, Euphorbiaceae, Fabaceae, Amaranthaceae, were the most representative in the survey. Species Cenchrus echinatus, Glycine max, Chamaesyce hirta, Commelina benghalensis, and Alternanthera tenella stood out in importance. The RR+millet soybean treatment had the highest number of species (44), while the conventional soybean + sorghum treatment had the lowest number of species (18). The highest number of species was recorded in first sampling period. Treatments conventional soybean + maize and conventional soybean + millet showed higher similarity (70%), while treatments RR soybean + millet and conventional soybean + sorghum showed the least (51%). Species of difficult control were recorded in all cultivation systems analyzed.

Cover-Crop Species as Distinct Biotic Filters in Weed Community Assembly

Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 282-295 ◽  
Author(s):  
Richard G. Smith ◽  
Lesley W. Atwood ◽  
Fredric W. Pollnac ◽  
Nicholas D. Warren
Keyword(s):  
Cover Crops ◽  
Community Assembly ◽  
Cover Crop ◽  
Weed Species ◽  
Seeding Rate ◽  
Crop Species ◽  
Cover Cropping ◽  
Directional Filtering ◽  
Weed Communities ◽  
Sorghum Sudangrass

Cover crops represent a potentially important biological filter during weed community assembly in agroecosystems. This filtering could be considered directional if different cover-crop species result in weed communities with predictably different species composition. We examined the following four questions related to the potential filtering effects of cover crops in a field experiment involving five cover crops grown in monoculture and mixture: (1) Do cover crops differ in their effect on weed community composition? (2) Is competition more intense between cover crops and weeds that are in the same family or functional group? (3) Is competition more intense across weed functional types in a cover-crop mixture compared with cover crops grown in monocultures? (4) Within a cover-crop mixture, is a higher seeding rate associated with more effective biotic filtering of the weed community? We found some evidence that cover crops differentially filtered weed communities and that at least some of these filtering effects were due to differential biomass production across cover-crop species. Monocultures of buckwheat and sorghum–sudangrass reduced the number of weed species relative to the no-cover-crop control by an average of 36 and 59% (buckwheat) and 25 and 40% (sorghum–sudangrass) in 2011 and 2012, respectively. We found little evidence that competition intensity was dependent upon the family or functional classification of the cover crop or weeds, or that cover-crop mixtures were stronger assembly filters than the most effective monocultures. Although our results do not suggest that annual cover crops exert strong directional filtering during weed community assembly, our methodological framework for detecting such effects could be applied to similar future studies that incorporate a greater number of cover-crop species and are conducted under a greater range of cover-cropping conditions.

scholarly journals Weed infestation of a cereal-legume mixture depending on its concentration and position in a crop rotation

2012 ◽  
Vol 65 (3) ◽  
pp. 99-108
Author(s):  
Marta K. Kostrzewska ◽  
Maria Wanic ◽  
Magdalena Jastrzębska
Keyword(s):  
Species Composition ◽  
Crop Rotation ◽  
Spring Barley ◽  
Similarity Index ◽  
Floristic Composition ◽  
Field Pea ◽  
Total Biomass ◽  
Weed Species ◽  
Weed Communities ◽  
Weed Infestation

A field study was carried out in the period 2000-2006 at the Experimental Station in Tomaszkowo belonging to the University of Warmia and Mazury in Olsztyn. Its aim was to compare weed infestation of a mixture of spring barley and field pea grown in a four crop rotation with different crop selection and sequence. Each year during tillering of spring barley and before the harvest of the mixture, weed species composition and density were evaluated, while additionally weed biomass was also estimated before the harvest. These results were used to determine species constancy, Simpson&rsquo;s dominance index, the Shannon-Wiener diversity and evenness indices as well as the community similarity index based on floristic richness, numbers and biomass of particular weed species. The cropping frequency and the position of the mixture in the crop rotation did not differentiate the species composition and total biomass of weed communities in the cereal-legume mixture crops. The crop rotation in which the mixture constituted 50% and was grown after itself had a reducing effect on weed numbers. Growing field pea in the 4-year crop rotation promoted weed infestation of the mixture and the dominance of weed communities. <em>Capsella bursa-pastoris</em>, <em>Chenopodium album</em>, <em>Echinochloa crus-galli</em>, <em>Elymus repens</em>, <em>Polygonum convolvulus</em>, and <em>Sonchus arvensis </em>were constant components of the agrophytocenoses. The weed communities were more similar in terms of their floristic composition than in terms of weed density and air-dry weight of weeds.

scholarly journals Use of solaria to predict weed density and floristic composition in no-till cropping systems

2006 ◽  
Vol 41 (3) ◽  
pp. 409-413 ◽  
Author(s):  
Pablo Antonio Calviño ◽  
Juan José Eyherabide
Keyword(s):  
Cropping Systems ◽  
Chenopodium Album ◽  
Floristic Composition ◽  
Weed Species ◽  
Transparent Plastic ◽  
Field Crops ◽  
No Till ◽  
Weed Communities ◽  
Setaria Verticillata ◽  
Ammi Majus

The objective of this work was to evaluate the efficiency of a new method, developed for predicting density and floristic composition of weed communities in field crops. Based on the use of solaria (100 mm transparent plastic tarps lying on the soil) to stimulate weed seedlings emergence, the method was tested in Tandil, Argentina, from 1998 to 2001. The system involved corn and sunflower in commercial no-till system. Major weeds in the experiments included Digitaria sanguinalis, Setaria verticillata and S. viridis, which accounted for 98% of the weed community in the three years of experiments since 1998. Large numbers of Tagetes minuta, Chenopodium album and Ammi majus were present in 2001. Comparison of weed communities under solaria with communities in field crops indicated that the method is useful for predicting the presence and density of some major weed species, at both high and low densities, of individuals in areas of 10 ha using only five solaria. Low density of weed species makes the method particularly useful to help deciding the time for herbicide applications to avoid soil contamination.

Differentiation of new coenomorph in context of the Belgard’s ecomorph system development

2017 ◽  
Vol 28 (1-2) ◽  
pp. 28-35 ◽  
Author(s):  
B. A. Baranovski
Keyword(s):  
Environmental Factors ◽  
Plant Species ◽  
Vascular Plants ◽  
Deciduous Forest ◽  
System Development ◽  
Vascular Plant ◽  
Tabular Form ◽  
Ecological Scales ◽  
The One ◽  
Different Levels

Nowadays, bioecological characteristics of species are the basis for flora and vegetation studying on the different levels. Bioecological characteristics of species is required in process of flora studying on the different levels such as biotopes or phytocenoses, floras of particular areas (floras of ecologically homogeneous habitats), and floras of certain territories. Ramensky scale is the one of first detailed ecological scales on plant species ordination in relation to various environmental factors; it developed in 1938 (Ramensky, 1971). A little later (1941), Pogrebnyak’s scale of forest stands was proposed. Ellenberg’s system developed in 1950 (Ellenberg, 1979) and Tsyganov’s system (Tsyganov, 1975) are best known as the systems of ecological scales on vascular plant species; these systems represent of habitat detection by ecotopic ecomorphs of plant species (phytoindication). Basically, the system proposed by Alexander Lyutsianovich Belgard was the one of first system of plant species that identiified ectomorphs in relation to environmental factors. As early as 1950, Belgard developed the tabulated system of ecomorphs using the Latin ecomorphs abbreviation; he also used the terminology proposed in the late 19th century by Dekandol (1956) and Warming (1903), as well as terminology of other authors. The article analyzes the features of Belgard’s system of ecomorphs on vascular plants. It has certain significance and advantages over other systems of ecomorphs. The use of abbreviated Latin names of ecomorphs in tabular form enables the use shortened form of ones. In the working scheme of Belgard’s system of ecomorphs relation of species to environmental factors are represented in the abbreviated Latin alphabetic version (Belgard, 1950). Combined into table, the ecomorphic analysis of plant species within association (ecological certification of species), biotope or area site (water area) gives an explicit pattern on ecological structure of flora within surveyed community, biotope or landscape, and on environmental conditions. Development and application by Belgrard the cenomorphs as «species’ adaptation to phytocenosis as a whole» were completely new in the development of systems of ecomorphs and, in this connection, different coenomorphs were distinguished. Like any concept, the system of ecomorphs by Belgard has the possibility and necessity to be developed and added. Long-time researches and analysis of literature sources allow to propose a new coenomorph in the context of Belgard’s system of ecomorphs development: silvomargoant (species of forest margin, from the Latin words margo – edge, boundary (Dvoretsky, 1976), margo – margin, ad margins silvarum – along the deciduous forest margins). As an example of ecomorphic characterization of species according to the system of ecomorphs by Belgard (when the abbreviated Latin ecomorph names are used in tabular form and the proposed cenomorph is used), it was given the part of the table on vascular plants ecomorphs in the National Nature Park «Orelsky» (Baranovsky et al). The Belgard’s system of ecomorphs is particularly convenient and can be successfully applied to data processing in the ecological analysis of the flora on wide areas with significant species richness, and the proposed ecomorph will be another necessary element in the Belgard’s system of ecomorphs. 

scholarly journals The Effect of Different Soil Tillage Systems and Crop Residues on the Composition of Weed Communities

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1276
Author(s):  
Vaida Steponavičienė ◽  
Aušra Marcinkevičienė ◽  
Lina Marija Butkevičienė ◽  
Lina Skinulienė ◽  
Vaclovas Bogužas
Keyword(s):  
Soil Ph ◽  
Crop Residues ◽  
Soil Tillage ◽  
Reduced Tillage ◽  
Plant Residues ◽  
No Tillage ◽  
Agricultural Crops ◽  
Weed Species ◽  
Tillage Systems ◽  
Weed Communities

The composition of weed communities in agricultural crops is dependent on soil properties and the applied agronomic practices. The current study determined the effect of different tillage systems and crop residue on the soil weed community composition. The research programme encompassed 2013–2015 in a long-term field experiment located in the Experimental Station of Vytautas Magnus University in Lithuania. The soil type in the experimental field was qualified as Endocalcaric Stagnosol (Aric, Drainic, Ruptic, Amphisiltic). Weeds were categorised into communities according to soil pH, nitrogen and moisture indicators. The results of investigations were grouped using cluster analysis. Agricultural crops were dominated by different weed species depending on the soil pH and moisture. Weed species were relatively more frequent indicating nitrogen-rich and very nitrogen-rich soils. In the reduced tillage and no-tillage systems, an increase in the abundance of weed species indicating moderate acidity and low acidity, moderately wet and wet, nitrogen-rich and very nitrogen-rich soils was observed. The application of plant residues decreased the weed species abundance. In the reduced tillage and no-tillage systems, the quantitative distribution of weed was often uneven. By evaluating the association of weed communities with groups of different tillage systems with or without plant residues, their control can be optimised.

scholarly journals The effectiveness of weed regulation methods in spring wheat cultivated in integrated, conventional and organic crop production systems

2012 ◽  
Vol 52 (4) ◽  
pp. 486-493 ◽  
Author(s):  
Beata Feledyn-Szewczyk
Keyword(s):  
Spring Wheat ◽  
Crop Production ◽  
Dry Matter ◽  
Production Systems ◽  
Integrated System ◽  
Integrated Systems ◽  
Conventional System ◽  
Weed Species ◽  
Organic System ◽  
Weed Communities

Abstract The research was conducted from 2008 to 2010, and compared the influence of different weed control methods used in spring wheat on the structure of the weed communities and the crop yield. The study was carried out at the Experimental Station of the Institute of Soil Science and Plant Cultivation - State Research Institute in Osiny as part of a long-term trial where these crop production systems had been compared since 1994. In the conventional and integrated systems, spring wheat was grown in a pure stand, whereas in the organic system, the wheat was grown with undersown clover and grasses. In the conventional system, herbicides were applied two times in a growing season, but in the integrated system - only once. The effectiveness of weed management was lower in the organic system than in other systems, but the dry matter of weeds did not exceed 60 g/m2. In the integrated system, the average dry matter of weeds in spring wheat was 4 times lower, and in the conventional system 10 times lower than in the organic system. Weed diversity was the largest in spring wheat cultivated in the organic system. In the conventional and integrated systems, compensation of some weed species was observed (Viola arvensis, Fallopia convolvulus, Equisetum arvense). The comparison of weed communities using Sorenson’s indices revealed more of a similarity between systems in terms of number of weed species than in the number of individuals. Such results imply that qualitative changes are slower than quantitative ones. The yield of grain was the biggest in the integrated system (5.5 t/ha of average). It was 35% higher than in the organic system, and 20% higher than in conventional ones.

Environmental factors including management practices as correlates of weed community composition in spring seeded crops

1992 ◽  
Vol 70 (10) ◽  
pp. 1931-1939 ◽  
Author(s):  
M. R. T. Dale ◽  
A. G. Thomas ◽  
E. A. John
Keyword(s):  
Community Composition ◽  
Correspondence Analysis ◽  
Canonical Correspondence Analysis ◽  
Environmental Variables ◽  
Management Practices ◽  
Geographic Region ◽  
Climatic Conditions ◽  
Weed Species ◽  
Weed Communities ◽  
Seed Crops

The relationship between the weed communities and environmental variables such as soil, crop, and management was investigated in two provinces of Canada. The frequencies of weed species were recorded in cereal and oilseed fields in Saskatchewan (2244 fields over 4 years) and Manitoba (864 fields over 3 years), Canada. Information on some of the physical characteristics of the fields and on the management practices imposed on them was also collected, in part by questionnaire. The two kinds of data were ordinated together using canonical correspondence analysis to assess the relationships between the species and the environmental variables. In the Saskatchewan data, there was a clear and consistent separation of the species into groups along an axis correlated with soil zone and the associated climatic gradient. In the Manitoba data, the same groups of species did not separate as clearly or as consistently, although geographic region was a major determinant of the weed communities. The greater variability may be due to the fact that the gradient of soil types is much more restricted in Manitoba and not as closely correlated with climatic conditions. In both provinces, culture practices were less important as correlates of the weed community composition than soil type or, to a certain extent, the previous crop. Key words: canonical correspondence analysis, cereal crops, oil seed crops.

scholarly journals Floristic composition and growth of weeds under custard apple (Annona squamosa) progenies

2004 ◽  
Vol 22 (4) ◽  
pp. 529-537 ◽  
Author(s):  
P.S.L. Silva ◽  
Z. Barbosa ◽  
O.F. Oliveira ◽  
R.P. Antonio ◽  
P.I.B. Silva
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Management Practices ◽  
Block Design ◽  
Floristic Composition ◽  
Negative Influence ◽  
Weed Species ◽  
Fresh Matter ◽  
Custard Apple ◽  
Root Collar

Weeds have a negative influence on several fruit tree characteristics, such as yield, making it difficult to management practices in orchards. Alternative weed management methods, aiming to reduce the use of herbicides, have become attractive since herbicides are costly and cause environmental degradation. The use of cultivars with greater competitive ability against weeds has attracted international attention. The objective of this work was to evaluate the floristic composition and growth of weeds under the canopies of irrigated custard apple tree progenies. Twenty halfsibling progenies around three years of age were evaluated in a random block design with five replicates and four plants per plot. A circle with a 0.5 m² area was established around the trunk of each plant. Floristic composition, fresh matter, and dry matter mass of the above-ground part of the weeds, were evaluated in this area. Root collar and canopy diameters, as well as leaf area of the progenies were also evaluated. Fifty-eight weed species were recorded. The five weed families with the most species were Leguminosae, Convolvulaceae, Euphorbiaceae, Malvaceae and Sterculiaceae, in decreasing order. The number of weed species per plot ranged from 6 to 18, but there was no difference between the mean percentages of different weeds under the canopies of the progenies. The lowest weed fresh and dry matter masses occurred in progenies JG1 and SM8, respectively. There were no differences between progenies with regard to root collar diameter and leaf area; however, one of the lowest weed dry matter yields was observed under the canopy of progeny FE4, which showed the largest canopy diameter.

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