scholarly journals Weed Species Trait Selection as Shaped by Region and Crop Diversity in Organically Managed Spring Cereals

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 433
Author(s):  
Merel A. J. Hofmeijer ◽  
Bo Melander ◽  
Jukka Salonen ◽  
Anneli Lundkvist ◽  
Livija Zarina ◽  
...  
Keyword(s):  
Species Traits ◽  
Organic Production ◽  
Crop Diversity ◽  
Weed Species ◽  
Organic Farms ◽  
Arable Farming ◽  
Regional Species Pool ◽  
Spring Cereals ◽  
Selection Of Species ◽  
Specific Species

Weeds remain a challenge in organic arable farming, as well as supply ecosystem services. The aim is to control weed densities while hosting a diverse and manageable weed community, preventing domination of few deleterious species. Therefore, we want to understand how specific species are stimulated, and which traits are selected for. This study focuses on crop diversity hypothesizing that (1) regions and (2) crop diversity function as filters for specific weed species traits. We conducted a weed monitoring in spring cereals over 2 years on organic farms in five northern European regions. Management and weed trait variables collected for the occurring species allowed an RLQ fourth-corner analysis. The weed communities were regionally specific, but trait selection was not observed, except in Latvia. Hence, the regional species pool provided different species with similar traits. Crop diversity within the management of spring cereals, such as undersowing and cereal frequency in the rotation, affected weed traits. The number of years under organic production selected no traits, although species numbers are known to increase. Hence, general weed species diversity increased, irrespective of traits. We conclude that organic management may support the agility within the weed community against selection of species and act as a buffer rather than as filter.

Comparing the Microbiological Status of Pre- and Postharvest Produce from Small Organic Production

2015 ◽  
Vol 78 (6) ◽  
pp. 1072-1080 ◽  
Author(s):  
AIXIA XU ◽  
DONNA M. PAHL ◽  
ROBERT L. BUCHANAN ◽  
SHIRLEY A. MICALLEF
Keyword(s):  
Food Safety ◽  
Organic Production ◽  
Wash Water ◽  
Small Scale ◽  
Organic Farms ◽  
Production Scale ◽  
Safety Risk ◽  
Leafy Greens ◽  
Postharvest Handling ◽  
Food Safety Risk

Consumption of locally, organically grown produce is increasing in popularity. Organic farms typically produce on a small scale, have limited resources, and adopt low technology harvest and postharvest handling practices. Data on the food safety risk associated with hand harvesting, field packing, and packing-house handling with minimal treatment, at this production scale, are lacking. We followed produce from small organic farms from the field through postharvest handling and packing. Pre- and postharvest produce (177 samples) and water (29 samples) were collected and analyzed quantitatively for Escherichia coli, total coliforms (TC), aerobic bacteria (APC), yeasts, molds (M), and enteric pathogens. No pathogens were recovered. E. coli was detected in 3 (3.6%) of 83 preharvest produce samples, 2 (6.3%) of 32 unwashed and 0 of 42 washed postharvest produce samples, and 10 (34.5%) of 29 water samples. No correlation was found between bacterial levels in irrigation water and those on produce. Postharvest handling without washing was a factor for APC and M counts on tomatoes, with lower frequencies postharvest. Postharvest handling with washing was a factor for leafy greens for TC counts, with higher frequencies postharvest. APC (P = 0.03) and yeast (P = 0.05) counts were higher in preharvest than in unwashed postharvest tomatoes. Washed postharvest leafy greens had higher M counts (P = 0.03) and other washed produce had higher TC counts (P = 0.01) than did their preharvest counterparts. Barriers were found to the use of sanitizer in wash water for leafy greens among small farms using organic practices. Hand harvesting and dry handling did not appear to be associated with a significant food safety risk, but washed leafy greens carried higher levels of some microbial indicators, possibly because of the lack of sanitizer in the wash water. The development of resources and materials customized for this sector of growers could enhance dissemination of information on best practices for handling of leafy greens.

scholarly journals Weed Species Diversity in the Czech Republic Under Different Farming and Site Conditions

2015 ◽  
Vol 63 (3) ◽  
pp. 741-749 ◽  
Author(s):  
Michaela Kolářová ◽  
Luděk Tyšer ◽  
Josef Soukup
Keyword(s):  
Czech Republic ◽  
Organic Farming ◽  
Chenopodium Album ◽  
Arable Land ◽  
Farming Systems ◽  
Weed Species ◽  
Organic Farms ◽  
Standard Size ◽  
The Czech Republic ◽  
Winter Cereals

The aim of this study was to explore the composition of weed vegetation on arable land in selected areas of the Czech Republic and to determine the level of γ-diversity. Our survey was conducted at 27 conventional and 35 organic farms from 2006–2008. In each sampled field, one phytocoenological relevé of a standard size of 100 m2 was recorded in the central part of the field. The species cover was estimated. The total γ-diversity was expressed as the total number of weed species recorded. γ-diversity of different farming systems, altitudes and crops was calculated. Subsequently, the species were divided on the basis of their perenniality. In total, 172 weed species were found – 123 and 162 in conventional and organic farming, respectively. The highest number of species was found in winter cereals and at medium altitudes. Chenopodium album was recorded as the species with the highest constancy in both types of farming. In total, 89 annuals, 17 biennials and 15 perennials were observed in conventional farming, and 109 annuals, 23 biennials, 28 perennials and 2 semiparasitic annuals were found in organic farming.

Community assembly and species traits

2019 ◽  
pp. 231-246
Author(s):  
Gary G. Mittelbach ◽  
Brian J. McGill
Keyword(s):  
Functional Traits ◽  
Community Assembly ◽  
Species Traits ◽  
Fundamental Question ◽  
Species Pool ◽  
Environmental Filters ◽  
Abiotic Environment ◽  
Local Site ◽  
Powerful Approach ◽  
Regional Species Pool

There is perhaps no more fundamental question in ecology than what determines the number and kinds of species found in a community and their relative abundances. This chapter lays out a powerful approach to answering this question, based on the concepts of a regional species pool and environmental filters. The species pool is the set of species that could potentially colonize a local site or community. Of these potential colonists, some species are limited in their ability to disperse to site, some are limited by their ability to survive the abiotic environment, and some are limited by their interactions with other species. These “filters” act individually or in concert, and the functional traits of species determine their success in passing through these filters to colonize a local site. There is growing empirical evidence that both abiotic and biotic processes select for specific functional traits. Focusing on the functional traits of species may lead to rules of community assembly that are general and help unify a variety of more specific theories.

Weeds and yields of spring cereals as influenced by stubble-cultivation and reduced doses of herbicides in five long-term trials

2000 ◽  
Vol 134 (3) ◽  
pp. 237-244 ◽  
Author(s):  
U. BOSTRÖM ◽  
M. HANSSON ◽  
H. FOGELFORS
Keyword(s):  
Weed Management ◽  
Plant Density ◽  
Crop Yields ◽  
Field Trials ◽  
Herbicide Application ◽  
Weed Species ◽  
Full Dose ◽  
Spring Cereals ◽  
One Year

The influence of herbicides at reduced rates and repeated stubble-cultivation on weeds and crop yields was estimated in five field trials with spring-sown cereals situated in the south of Sweden during the autumn of 1989 until the spring of 1997. Stubble-cultivation was accomplished during 1989–1996, while herbicides were applied at 0, 1/8, 1/4 or 1/2 of full dose during 1990–1996.In the spring of 1997, i.e. after 7 years without herbicide application, seedling densities 3 weeks after weed emergence were 68–340/m2 at three sites and 535–610/m2 at two sites when averaged over tillage treatments.Averaged over herbicide doses, stubble-cultivation reduced the plant density of annual broad- leaved weeds by 6–32% at three sites and increased the density by 25% at one site. At the remaining site, the density was not significantly influenced. Stubble-cultivation reduced the populations of two perennial and seven annual weed species, while one species was stimulated and nine species showed null, or inconsistent, responses. In the spring of 1997, i.e. one year after the last herbicide application, the densities of weed seedlings in 1/8, 1/4 and 1/2-doses were 34, 46 and 56% lower, respectively, than in the untreated controls.Stubble-cultivation increased crop yields at four sites by 200 kg/ha as a mean over herbicide doses. At these four sites, averaged over 1993–1995, herbicides increased yields in plots that were not stubble-cultivated by 7, 8 and 10% in the 1/8, 1/4 and 1/2 of a full dose, respectively, relative to the untreated control. In 1996, herbicides increased yields at only two sites.It is concluded that a fruitful way for weed management with a low input of agrochemicals is to combine the use of herbicides at reduced rates with repeated stubble-cultivation.

Reversion from organic to conventional agriculture: A review

2012 ◽  
Vol 28 (3) ◽  
pp. 263-275 ◽  
Author(s):  
Henriette Sahm ◽  
Jürn Sanders ◽  
Hiltrud Nieberg ◽  
Gesine Behrens ◽  
Heike Kuhnert ◽  
...  
Keyword(s):  
Absolute Number ◽  
Organic Production ◽  
Policy Support ◽  
Main Role ◽  
Market Demand ◽  
Organic Farms ◽  
Conventional Agriculture ◽  
Organic Certification ◽  
The Past ◽  
And Control

AbstractOver the past 10 years, the organic sector has expanded continuously in Europe due to policy support and a growing market demand for organic products. In line with this development, many farmers converted to organic farming each year. Nevertheless, the total number of organic farms has not increased constantly in Europe. In several countries, the absolute number of organic farms actually decreased in some years of the past decade. Some of the deregistered farmers gave up completely; others reverted to conventional agriculture. Against this background, this article aims (i) to give an overview of the extent of reversion to conventional agriculture in Europe based on statistics, (ii) to conceptualize the decision to revert in the form of a theoretical model, (iii) to compare farmers’ reasons to revert to conventional farming based on existing studies, and (iv) to identify further research needs. The importance of reversions to conventional agriculture is difficult to determine with the existing data, especially as in most cases it is not recorded as to what happened to the farms after deregistering from organic certification. The data nevertheless show that there are large fluctuations in the organic sector with many farmers entering and exiting each year. In order to reveal the farmers’ reasons for deregistering, various qualitative as well as quantitative surveys have been carried out already. For most farmers, the decision to revert is a result of different factors. Reasons for the reversion of their farms can be classified into economic motives, difficulties regarding certification and control, problems with organic production techniques as well as the farms’ macro environment. In most cases, however, economic reasons played a main role. Suggestions for organic legislation bodies, advisory services and policy makers are derived out of the findings. A deeper understanding of the influencing aspects regarding reversions and the necessary changes in the organic sector to avoid them should be an important objective of forthcoming research.

Burning Nettle, Common Purslane, and Rye Response to a Clove Oil Herbicide

2006 ◽  
Vol 20 (3) ◽  
pp. 646-650 ◽  
Author(s):  
Nathan S. Boyd ◽  
Eric B. Brennan
Keyword(s):  
Weed Management ◽  
Production Systems ◽  
Dry Weight ◽  
Organic Production ◽  
Management Tool ◽  
Vegetable Production ◽  
Clove Oil ◽  
Organic Farms ◽  
High Concentrations ◽  
Common Purslane

Weed management is often difficult and expensive in organic production systems. Clove oil is an essential oil that functions as a contact herbicide and may provide an additional weed management tool for use on organic farms. Burning nettle, purslane, and rye responses to 5, 10, 20, 40, and 80% v/v clove oil mixture applied in spray volumes of 281 and 468 L/ha were examined. Log-logistic curves were fitted to the nettle and purslane data to determine the herbicide dose required to reduce plant dry weight 50% (GR50) and 90% (GR90). A three-parameter Gaussian curve was fitted to the rye data. The GR50 and GR90 were largely unaffected by spray volume. Nettle dry weight was reduced by 90% with 12 to 61 L clove oil/ha, whereas 21 to 38 L clove oil/ha were required to reduce purslane biomass to the same level. Rye was not effectively controlled by clove oil. Clove oil controls broadleaf weeds at high concentrations, but its cost makes broadcast applications prohibitive, even in high-value vegetable production systems.

scholarly journals A Conceptual Framework for Choosing Target Species for Wildlife-Inclusive Urban Design

2019 ◽  
Vol 11 (24) ◽  
pp. 6972 ◽  
Author(s):  
Beate Apfelbeck ◽  
Christine Jakoby ◽  
Maximilian Hanusch ◽  
Emanuel Boas Steffani ◽  
Thomas E. Hauck ◽  
...  
Keyword(s):  
Urban Development ◽  
Conceptual Framework ◽  
Urban Design ◽  
Spatial Scales ◽  
Species Traits ◽  
Species Selection ◽  
Target Species ◽  
Current Conservation ◽  
Starting Point ◽  
Regional Species Pool

Recent research has highlighted the significance of cities for biodiversity, making them important places for conservation in their own right. Current conservation approaches in cities are mostly defensive. Thus, they focus on remnant pockets of natural areas or try to protect particular species that occur in the built environment. These approaches are vulnerable to further urban development and do not create habitats. An alternative strategy is to make wildlife an integral part of urban development and thereby create a new habitat in the built-up area. Here we address the challenge of choosing target species for such wildlife-inclusive urban design. The starting point of our conceptual framework is the regional species pool, which can be obtained from geo-referenced species data. The existing habitat types on and around the development site and dispersal barriers limit the species numbers to the local species potential. In the next step, the site’s potential for each species is analyzed—how can it be upgraded to host species given the planned development and the life-cycle of the species? For the final choice of target species, traits related to the human–animal interaction are considered. We suggest that stakeholders will be involved in the final species selection. Our approach differs from existing practice, such as expert choice of priority species, by (1) representing an open process where many species are potential targets of conservation, (2) the involvement of stakeholders in a participatory way. Our approach can also be used at larger spatial scales such as quarters or entire cities.

FINACIAL FUNDS FROM EUROPEAN UNION FUNDS AS A CHANCE FOR THE DEVELOPMENT OF THE SECTOR OF ORGANIC FARMS IN POLAND

2017 ◽  
Vol XIX (2) ◽  
pp. 95-101
Author(s):  
Aleksandra Jezierska-Thöle ◽  
Mirosław Biczkowski
Keyword(s):  
European Union ◽  
Organic Farming ◽  
Agricultural Policy ◽  
Agricultural Land ◽  
Development Program ◽  
Organic Production ◽  
Organic Farms ◽  
Rural Development Program ◽  
The Impact ◽  
Theoretical Foundations

The aim of the work was to present and describe the development of organic farms in Poland and the impact of EU funds on the development of this sector. The possibilities of financing their development from the Rural Development Program funds in the period 2007-2013 functioning within the framework of the Union‘s Common Agricultural Policy were pointed out. The theoretical foundations and assumptions related to the functioning of the organic farming sector were also approximated. The results show that in the years 2002-2013 there was an increase in the number and area of organic farms. The greatest impact on the increase of the number and area of organic farms is the functioning of the RDPs in the years 2004-2006 and 2007-2013 and within it the subsidies for organic production. This confirms the very strong correlation between the number of farms and the amounts of subsidies paid to farms producing organic farming. It can be assumed that in the next few years the share of the area of ecological agricultural land may exceed 4-5%.

Differentiation of Life-History Traits among Palmer Amaranth Populations (Amaranthus palmeri) and Its Relation to Cropping Systems and Glyphosate Sensitivity

Weed Science ◽  
2017 ◽  
Vol 65 (3) ◽  
pp. 339-349 ◽  
Author(s):  
Washington Bravo ◽  
Ramon G. Leon ◽  
Jason A. Ferrell ◽  
Michael J. Mulvaney ◽  
C. Wesley Wood
Keyword(s):  
Life History ◽  
Crop Rotation ◽  
Life History Traits ◽  
Cropping Systems ◽  
Glyphosate Resistance ◽  
The United States ◽  
Organic Production ◽  
Palmer Amaranth ◽  
Flowering Plant ◽  
Weed Species

Palmer amaranth’s ability to evolve resistance to different herbicides has been studied extensively, but there is little information about how this weed species might be evolving other life-history traits that could potentially make it more aggressive and difficult to control. We characterized growth and morphological variation among 10 Palmer amaranth populations collected in Florida and Georgia from fields with different cropping histories, ranging from continuous short-statured crops (vegetables and peanut) to tall crops (corn and cotton) and from intensive herbicide use history to organic production. Palmer amaranth populations differed in multiple traits such as fresh and dry weight, days to flowering, plant height, and leaf and canopy shape. Differences between populations for these traits ranged from 36% up to 87%. Although glyphosate-resistant (GR) populations collected from cropping systems including GR crops exhibited higher values of the aforementioned variables than glyphosate-susceptible (GS) populations, variation in traits was not explained by glyphosate resistance or distance between populations. Cropping system components such as crop rotation and crop canopy structure better explained the differences among populations. The higher growth of GR populations compared with GS populations was likely the result of multiple selection forces present in the cropping systems in which they grow rather than a pleiotropic effect of the glyphosate resistance trait. Results suggest that Palmer amaranth can evolve life-history traits increasing its growth and reproduction potential in cropping systems, which explains its rapid spread throughout the United States. Furthermore, our findings highlight the need to consider the evolutionary consequences of crop rotation structure and the use of more competitive crops, which might promote the selection of more aggressive biotypes in weed species with high genetic variability.

scholarly journals Weed infestation of cereal stubble-fields in the Lublin region

2013 ◽  
Vol 39 (1) ◽  
pp. 143-164
Author(s):  
Franciszek Pawłowski ◽  
Maria Jędruszczak
Keyword(s):  
Species Composition ◽  
Loess Soil ◽  
Weed Species ◽  
Weed Infestation ◽  
Specific Species

Results presented concern the species composition, constancy (S) and indices of coverage (D) of weeds on the cereal stubble-fields on various soils in the Lublin region. The report was based upon 456 phytosociological records collected in 130 stands after harvest in the years 1975-1980. In total 245 weed species were found. They were the scarcest on loose sands - 65 species, and the most abundant on loess soil - 158 species. Each kind of soil was characterized by a specific species composition, various degrees of constancy and indices of coverage of weeds.

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