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Mulch materials of different origin and colour are available in the agricultural sector as sustainable alternatives to the use of polyethylene (PE). Mulching modifies soil temperature and consequently affects crop yields. This work assessed the thermal and productive responses of different mulch materials in two different geo-climatic conditions during a 3-year integrated field study on processing tomato (Lycopersicon esculentum Mill.). Two biodegradable plastic mulches (BD1, BD2), one oxo-degradable material (OB), two types of paper (PP1, PP2) and one barley-straw cover (BS) were compared with two control treatments: black PE and manual weeding (MW). Soil temperature variables (maximum, minimum and mean temperature, soil growing degree-days and soil temperature amplitude) and production variables (marketable and total yield, mean fruit weight) were considered. Thermally, PE could be considered an atypical mulch causing higher temperatures in the soil, but it is not associated with a higher yield. Responses of PE, PP2 and MW were independent of the geo-environmental conditions, whereas OB, BDI and BD2 had similar thermal and productive responses to each other in different environments. Tomato yield was correlated positively only with the minimum soil temperature, especially when excluding PE. Additional keywords: mulching, soil temperature, yield, polyethylene, degradable plastics, papers., Introduction Mulching is a technique used in cultivation worldwide, especially for vegetable crops, offering many advantages. Mulches reduce weed growth, minimise or eliminate soil erosion, and often enhance total yields [...]

Over the last 30 years, many studies have surveyed weed vegetation on arable land. The 'Arable Weeds and Management in Europe' (AWME) database is a collection of 36 of these surveys and the associated management data. Here, we review the challenges associated with combining disparate datasets and explore some of the opportunities for future research that present themselves thanks to the AWME database. We present three case studies repeating previously published national scale analyses with data from a larger spatial extent. The case studies, originally done in France, Germany and the UK, explore various aspects of weed ecology (community composition, management and environmental effects and within‐field distributions) and use a range of statistical techniques (canonical correspondence analysis, redundancy analysis and generalised linear mixed models) to demonstrate the utility and versatility of the AWME database. We demonstrate that (i) the standardisation of abundance data to a common measure, before the analysis of the combined dataset, has little impact on the outcome of the analyses, (ii) the increased extent of environmental or management gradients allows for greater confidence in conclusions and (iii) the main conclusions of analyses done at different spatial scales remain consistent. These case studies demonstrate the utility of a Europe‐wide weed survey database, for clarifying or extending results obtained from studies at smaller scales. This Europe‐wide data collection offers many more opportunities for analysis that could not be addressed in smaller datasets; including questions about the effects of climate change, macro‐ecological and biogeographical issues related to weed diversity as well as the dominance or rarity of specific weeds in Europe. [ABSTRACT FROM AUTHOR]

Questions: Two scientific disciplines, vegetation science and weed science, study arable weed vegetation, which has seen a strong diversity decrease in Europe over the last decades. We compared two collections of plot‐based vegetation records originating from these two disciplines. The aim was to check the suitability of the collections for joint analysis and for addressing research questions from the opposing domains. We asked: are these collections complementary? If so, how can they be used for joint analysis? Location: Europe. Methods: We compared 13 311 phytosociological relevés and 13 328 records from weed science, concerning both data collection properties and the recorded species richness. To deal with bias in the data, we also analysed different subsets (i.e., crops, geographical regions, organic vs conventional fields, center vs edge plots). Results: Records from vegetation science have an average species number of 19.0 ± 10.4. Metadata on survey methodology or agronomic practices are rare in this collection. Records from weed science have an average species number of 8.5 ± 6.4. They are accompanied by extensive methodological information. Vegetation science records and the weed science records taken at field edges or from organic fields have similar species numbers. The collections cover different parts of Europe but the results are consistent in six geographical subsets and the overall data set. The difference in species numbers may be caused by differences in methodology between the disciplines, i.e., plot positioning within fields, plot sizes, or survey timing. Conclusion: This comparison of arable weed data that were originally sampled with a different purpose represents a new effort in connecting research between vegetation scientists and weed scientists. Both collections show different aspects of weed vegetation, which means the joint use of the data is valuable as it can contribute to a more complete picture of weed species diversity in European arable landscapes. [ABSTRACT FROM AUTHOR]

Teosinte is an invasive weed which emerged recently in Northeastern Spain, an important corn-growing region in Western Europe. It is causing substantial agronomic and economic damages and is threatening the availability of corn in the region. Farmers and regulatory agencies can choose from a number of strategies to control for teosinte infestations including adoption of specific cultural practices such as manual control constructing false seedbeds, as well as adopting corn rotations with other annual and perennial crops. In spite of the potential negative impacts of this weed, little is known about what the optimal control strategies are, both from the private (e.g. the farm) and social (e.g. regulatory agencies) perspectives. In response, we develop a dynamic optimization model to identify the sequence of control strategies that minimize private and social costs under low- and high-infestation level scenarios, for a fifteen-year planning horizon. We calibrate the model using biological data from experimental trials and economic parameters collected from farmers in the region. Our results suggest the economic losses of teosinte infestation can reach up to 9229 and 9398 €/ha for low- and high-infestation scenarios if nothing is done to control it. In addition, results show that optimal private and social strategies are different. For example, under high-infestation levels, private losses are minimized at 26.5% by not controlling in years 1–2, use false seedbeds in year 3, planting alfalfa in years 4–8, and planting corn thereafter in the total area. In contrast, social costs are minimized at 27.9% by adopting rotations starting year, return to corn mono-cropping in half the area after year four. Results show false seedbed and manual controls, currently recommended by the regulatory agency in low-infestation cases, are not socially optimal. [ABSTRACT FROM AUTHOR]

The article discusses a study which tested the effectiveness of 20 herbicides in herbicide-resistant Lolium rigidum Gaud (L. rigidum) weed species in Spain. Results reveal the efficacy of prosulfocarb with trifluralin, triasulfuron, or chlortoluron on six populations during pre-emergence application. It notes that the diverse effectiveness patterns of the various populations of L. rigidum show the need for comprehensive data of the populations before applying herbicides.

"Arable Weeds and Management in Europe" is a collection of weed vegetation records from arable fields in Europe, initiated within the Working Group Weeds and Biodiversity of the European Weed Research Society (EWRS). Vegetation-plot data from this scientific community was not previously contributed to databases. We aim to prove the usefulness of collection for large scale studies through some first analyses. We hope to assure other weed scientists who have signalled willingness to share data, and plan to construct a full data base, making the data available for easy sharing. Presently, the collection has over 60,000 records, taken between 1996 and 2015. Many more studies for potential inclusion exist. Data originate mostly from studies exploring the effect of agricultural management on weed vegetation. The database is accompanied with extensive meta-data on crop and weed management on the surveyed fields. The criteria for inclusion were a minimum amount of information on the cultivated crop, and a georeference. Most fields were surveyed repeatedly, i.e. transects, multiple random plots, or repeated visits. All surveys aimed to record the complete vegetation on the plots. Sometimes, taxa were identified only to genus level, due to survey dates very early in the vegetation period. Plant taxonomy is standardized to the Euro+Med PlantBase. [ABSTRACT FROM AUTHOR]

The species belonging to the genus Echinochloa represent the main weeds in rice fields worldwide. Heavy soils are especially appropriate for this crop that is often grown in monoculture. A drought period in 2012 impeded farmers from sowing rice in some parts of the region of Aragon (northeastern Spain) and, unusually, they seeded alternative crops such as winter cereal, fescue (Festuca arundinacea), ryegrass (Lolium multiflorum) and lucerne (Medicago sativa). A total of 20 fields were selected, in which rice had been grown in monocrop until 2011 and several crop sequences were established afterwards; weed vegetation was recorded in spring, summer and autumn 2014-16 to find out if the crop rotations reduced weed infestations. Winter cereal and fescue were the crops with the highest soil cover; ryegrass and lucerne had difficulties in installation probably due to the heavy soil textures. Echinochloa spp. plants were found in the winter cereal stubble after having grown fescue for the previous two years and rice before that; in the forage fields, small plants of earing Echinochloa spp. adapted to mowing were detected. Recommendations for Integrated Weed Management that arise from the observations are ploughing the winter cereal stubble before seed shed of the emerged Echinochloa plants, assuring a high density of the forage crops, and efficient herbicide control in rice fields. [ABSTRACT FROM AUTHOR]

Herbicide weed control is difficult in the first years of perennial crop establishment or in minor crops, and plastic sheet mulches can leave persistent residues. Liquid spray-on mulch (hydromulch) might be a solution in these cases. To test three hydromulch formulations on perennial weed emergence, greenhouse assays were conducted for two years in two localities to evaluate their rhizome sprouting and shoot emergence. Data, obtained from a completely randomized block design, were analyzed by means of generalized linear mixed models with binomial distribution and logit link function; the effects of hydromulch, species, and their interaction were considered fixed, while the other sources of variation (i.e., locality, year, block and rhizome length) were considered random. All three hydromulches, based on wheat straw, rice husk, and used substrate for mushroom cultivation, were capable of reducing rhizome sprouting of all four species tested when compared to the non-mulched treatment. Many rhizomes sprouted but were trapped under the mulch layer, especially those of Paspalum dilatatum (87%), Cynodon dactylon, and Sorghum halepense (around 50%), while Cyperus rotundus was least affected by the hydromulch treatments (16%). All three blends showed promising results in the reduction of perennial weed emergence, warranting field trials to test combined weed management strategies. [ABSTRACT FROM AUTHOR]

Spatial externalities, such as the sharing of harvesting equipment by many farmers, have an impact on the control of invasive species in the agricultural environment. In these cases, the regulator must design a set of measures to promote coordinated control by affected parties. We aim to analyze the determinants of private versus collective control efforts in the case of a particular invasive species (teosinte) occurring as a weed in corn fields throughout North-Eastern Spain. Using a simple discrete space-dynamic framework, we model the effect of the decisions made by the farmer of an infested plot on a noninfested plot, with the harvester being the only potential pathway for the invader to spread and assuming a one-way invasion. The results reveal that failure to adopt optimal cooperative strategies causes losses to other plots if they become infested amounting to an annual average of EUR 322/ha, when the infestation is low, and EUR 364/ha, when it is high. Results suggest that cleaning the harvester, a measure currently recommended by the regulatory agency in low-infestation cases but that does not guarantee that the machine is completely clean, is not socially optimal if monocropping practices are permitted in the region. [ABSTRACT FROM AUTHOR]

Complaints about the lack of control of Rapistrum rugosum with tribenuron-methyl and iodosulfuron-methyl-sodium in winter cereals in Northeastern Spain motivated this study. During 2015–2018, greenhouse trials were conducted to test the responses of two possibly resistant (R1 and R2) and two susceptible populations to both active ingredients to determine the response of these populations to alternative herbicides. In the first trial that was repeated twice, populations were treated with both active ingredients (three rates, six replicates), and the lack of control confirmed resistance both times. The second trial was conducted on the self-pollinated progeny of the initial populations (13 rates, 6 replicates) to confirm the heritable character of resistance and to determine the resistance factors related to survival and biomass. Resistance factors based on biomass were 188 and 253 for tribenuron-methyl and 42 and 26 for iodosulfuron-methyl-sodium for R1 and R2, respectively, confirming the strong resistance of the progeny. In the third trial, nine active ingredients (a.i.) registered for broadleaved weed control in winter cereals were tested on the four populations (two rates, four replicates). All the alternative herbicides, except florasulam, results in important phytotoxicity to all tested populations, with 100% efficacy for several a.i. This work is the first report of R. rugosum that is resistant to iodosulfuron-methyl-sodium and the first report in Europe of R. rugosum that is resistant to tribenuron-methyl. [ABSTRACT FROM AUTHOR]

Onobrychis viciifolia (Scop.) (sainfoin) is promoted in the Spanish Aragón region through the Agro-Environmental Schemes (AES) since 2007 with the aim of enhancing biodiversity. Also, in other countries, the interest in this legume crop is growing due to its rusticity and beneficial effects on the soil and livestock. However, the effect of the crop on weed flora in the subsequent cereal crops has hardly been investigated yet. With this aim, weed flora has been characterised in 2011–2014 in sainfoin fields in the second and third year of establishment (S2 and S3), in cereal monocrop (CM), in cereal after sainfoin (CS) and in organic cereal fields (OC). Additionally, the soil seedbank was determined in two years in CM and S3 fields. Weed species richness of emerged flora and of the soil seedbank was highest for sainfoin and lowest for CM, being intermediate for OC and CS regardless of the sampling year. The most feared weed species in winter cereal did not increase by growing sainfoin or in CS compared to CM. Curiously, summer annuals dominated in the soil seedbank. Sainfoin fields cause thus a shift in the weed flora, which does not seem to damage subsequent cereal crops provided fields are mouldboard ploughed after sainfoin. [ABSTRACT FROM AUTHOR]

Black polyethylene (PE) is the most common mulching material used in horticultural crops in the world but its use represents a very serious environmental problem. Biodegradable films and paper mulches are available alternatives but farmers are reluctant to adopt them because of their high market prices. The aim of this paper is to evaluate the economic profitability of eight biodegradable mulching materials available for open-air pepper production. The economic evaluation is based on a four-year trial located in a semi-arid region of Spain. Three scenarios of PE waste management are examined: (i) absence of residues management, (ii) landfill accumulation, and (iii) total recycling. The inclusion of the costs of waste management and recycling under the current Spanish legislation only reduced the final net margin by 0.2%. The results show that an increase in subsidy rates of up to 50.1% on the market price would allow all biodegradable films to be economic alternatives to PE. The study supports the mandatory measures for the farmers to assume the costs of waste management and recycling. Despite savings in field conditioning costs, high market prices of biodegradable materials and papers are not compensated by the current level of subsidies, hampering their adoption in the fields. [ABSTRACT FROM AUTHOR]

Amaranthus palmeri S. Watson is a dioecious broad‐leaved species characterised by rapid growth, high seed production, efficient resource use and adaptability to diverse environments and cropping systems. A. palmeri populations are spreading beyond their native range in south western United States, into the Mediterranean region and have been reported in several European and Mediterranean countries. First stands were located along roadsides, and later in nearby agricultural fields. Possible routes of introduction include contaminated animal feed and grain shipments for industrial processing. Some European A. palmeri populations appear to be already resistant to 5‐enolpyruvylshikimate‐3‐phosphate synthase and acetolactate synthase inhibitors when imported. Recent studies suggest that this trait may have evolved in the origin country before the introduction into southern Europe and the wider Mediterranean region. Effective, transboundary networks have to be established between farmers and researchers to raise agricultural community awareness and continuously monitor the invasiveness of A. palmeri in Europe. In this review, we first highlight botanical characteristics that allow accurate identification of A. palmeri from closely related Amaranthus species. Then, we summarise recent reports on the occurrence of A. palmeri in Europe and the Mediterranean region. We proceed to assess future invasion and spread across Europe according to climate and agricultural practices. In addition, we review measures to early detect A. palmeri and emphasised on feasible, chemical and non‐chemical weed control methods as components of integrated weed management to mitigate the impact of A. palmeri invasion on European agriculture. [ABSTRACT FROM AUTHOR]