Bassia scoparia (L.) Voss has evolved resistance to five herbicide modes of action (MoAs) worldwide, including multiple resistance to up to four MoAs. Seeds were collected from a putatively resistant B. scoparia population (GUI-R) that survived successive herbicide applications of synthetic auxins, acetolactate synthase (ALS), and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibitors in a no-till winter cereal field in Catalonia, Spain, in 2022, to assess resistance levels and mechanisms. Dose-response assays confirmed that GUI-R was 2-, 340-, 42.7-, and 60-fold more resistant to glyphosate, thifensulfuron, MCPA, and 2,4-D, respectively, based on plant weight, and 3.2-, 123-, 57.9-, and 32-fold more resistant based on plant survival. GUI-R showed cross-resistance to imazamox (46 % survival), but not to dicamba or fluroxypyr (100 % mortality), at the label rate. Preliminary studies using malathion pre-treatment, a cytochrome P450 inhibitor, reversed 2,4-D resistance in GUI-R at the label rate, resulting in a 97 % reduction in biomass. Molecular studies revealed that GUI-R has 4.9 additional copies of the EPSPS:ALS gene, with no known mutations and less shikimate accumulation than the susceptible population. ALS gene sequencing identified the Pro197Ser, Pro197Leu, and Trp574Leu mutations, along with a combined Pro197Ser + Trp574Leu mutation. In conclusion, EPSPS gene amplification and ALS mutations confer target-site resistance to glyphosate, thifensulfuron and imazamox in GUI-R. Resistance to 2,4-D and MCPA is probably driven by P450-mediated non-target-site resistance and further research is necessary to confirm mechanisms. This biotype represents the first case of glyphosate resistance in Europe for the species, as well as the first triple resistance.

Winter cereal in rainfed conditions occupies an important area in Spain and also in Arag & oacute;n and has experienced significant changes concerning management and social aspects. In this work the opinions of 38 technicians and farmers of 21 districts are described after filling in questionnaires about the main crops, type of tillage, herbicide use, main weed species, sowing periods, etc. in three periods: years 1970-86 (since the inclusion of Spain in the CEE and the start of the influence of the Common Agricultural Policies) (period 1), 2005-13 (period 2) and 2021-present (period 3). The results are coincident in most of the districts concerning the following aspects: more diverse crops have been seeded progressively; a reduction in tillage intensity has occurred and herbicides are applied more intensively, in many districts in both pre- and postemergence of the crops. Concerning the most worrisome weeds, the most outstanding is an increase in poaceae, especially of Lolium rigidum Gaud. in many areas showing herbicide-resistant populations at least in 7 districts. Overall, grazing with sheep has also diminished and there has been an increase of the cultivated area per farmer. The irregular rainfall as well as the high temperatures at the end of the cropping cycles will very probably force farmers to carry out new adaptations such as choosing adapted species (e.g. barley) and appropriate varieties to these conditions to capitalize the crops.

Weeds currently represent the most important factor limiting agricultural production, causing crop yield reductions estimated at 34% globally [1]. At present, herbicides and tillage are the most common weed control methods, and also plastic mulches for horticultural crops. However, the use of these techniques can cause negative effects: intensive tillage increases soil erosion, leading to a loss of fertility [2]; the use of herbicides pollutes the soil, water, food and air [3], and can cause phytotoxicities in young woody saplings or leave residues in aromatic or horticultural crops [4]; plastic mulches are difficult to recycle and have a negative impact on the environment because of its long degradation period [5]. In this context, and with the aim of avoiding these negative effects, hydromulches can be a more environmentally-friendly alternative, considering as such own made pasty mulches that dry out after application. In this work, we present the coordinated research project “Hydromulches in woody, horticultural crops and urban environments for weed control and water saving which contribute to circular bioeconomy” (HMulchCircle) (ref. PID2020-113865RR), developed in Spain by different research teams from different institutions. The project complements a previous one (ref. RTA-2015-00047-C5), focused on the use of some hydromulches based on by-products derived from the agricultural sector, mixed with a binder and recycled paper paste and applied liquidly on the ground with subsequent solidification, and has the following objectives: 1) Evaluation of mechanized application of the two hydromulch blends that have shown the longest duration and potential in the previous project in different crops. Optimization of the mechanical application, monitoring and study of the effect on weed control. 2) Elaboration of new blends including own-made paper slurry and other lignocellulosic materials that contribute to the circular bioeconomy of each crop and agrifood industry, and characterization of the new blends (on bare soil). 3) Study of the life span of the new hydromulch materials and the weed control capacity in different crops (oak trees, aromatic plants, vegetables, saffron, vineyards, almond trees, fruit trees, forest tree nurseries, public gardens). 4) Effect of the new materials on the growth, productivity and quality of the different crops, and their interaction with the soil properties. 5) Economic, environmental and social assessments of the hydromulch use. The multidisciplinary nature of the project and its developing in different edapho-climatic conditions and crops will allow solid conclusions to be drawn about the usefulness of the resulting hydromulches within the framework of the circular bioeconomy and a sustainable agriculture. References: 1. Chauhan, B. S. 2020. Front. , 1:3. 2. Guccione, G.; Schifani, G. 2001. J. Econ. Agric. Environ., 3, 29-36. 3. Monteiro, A.; Santos, S. 2022. Agronomy, 12, 118. 4. Carrubba, A., Militello, M. 2013. Agron. Sustain. Dev., 33, 551-561. 5. Ghatge, S.; Yang, Y.; Ahn, J.H.; Hur, H.G. 2020. Appl. Biol. Chem., 63, 1-14. Keywords: mulch, weeds, sustainable agriculture. Acknowledgements: PID2020-113865RR/AEI/10.13039/501100011033 (Spanish Ministry of Science and Innovation).

El cereal de invierno en secano ocupa una importante superficie en España, también en Aragón, y en las últimas décadas ha sufrido considerables cambios de manejo agronómicos, sociales y de gestión. En el presente trabajo se sintetizan las opiniones de 38 técnicos y agricultores de 21 comarcas consultados a través de cuestionarios sobre los principales cultivos, tipo de laboreo, usos de herbicidas, malas hierbas dominantes, fechas de siembra, etc. en tres épocas: años 1970‑86 (inicio de la influencia de la PAC) (período 1), 2005‑13 (período 2) y 2021 hasta la actualidad (período 3). Los resultados son coincidentes en la mayoría de las comarcas en los siguientes aspectos: de forma progresiva se siembra una mayor diversidad de cultivos, ha tenido lugar una reducción de la intensidad de laboreo y se ha producido un creciente aumento en el uso de herbicidas, utilizándose en la actualidad en muchas comarcas en pre y postemergencia de los cultivos. En cuanto a las arvenses de más difícil control destaca el incremento de especies poáceas, sobre todo Lolium rigidum Gaud. que ha aumentado en muchas zonas y presenta resistencia a herbicidas en al menos 7 comarcas. El pastoreo con ovino ha disminuido de forma generalizada y la superficie gestionada por agricultor ha aumentado por motivos económicos. Las irregulares precipitaciones, en progresiva disminución, y también los incrementos de temperatura a finales de ciclo posiblemente obligarán a realizar nuevas adaptaciones como la elección de especies (p.ej. cebada) o variedades apropiadas a estas condiciones para poder rentabilizar los cultivos.

Hydromulch, used primarily for erosion control, is now being studied as a weed control method in perennial crops and public gardens where weed control is especially difficult; the most challenging species are perennials having powerful shoots that emerge from subterranean propagules. In a previous article, we considered rhizome sprouting capacity through three experimental hydromulches based on wheat straw (WS), rice husk (RH) and used mushroom substrate (UMS). Here, we present data for the number of emerged shoots and their biomass to test whether the mulches were able to influence outcomes affecting weed-crop competition. In addition, the mechanical resistance of these hydromulches was characterized in terms of punching stress or resistance, considering two air humidity levels and applying an artificial ageing test (AAT) to simulate an average spring rainfall for Mediterranean areas. All three mulching types were effective in reducing the weed biomass (60–85

Background and aims Germination as a function of soil water potential (h) is modelled using polyethylene glycol (PEG). But, PEG would not consider soil properties. Our objective is to show the limitations of PEG to model germination in real soils. Using a new device, the tension germinator (TG), we show the interaction between soil type, h and seed characteristics on seed germination. Methods TG (A Mariotte reservoir that supplies water at constant h to a porous substrate on which seeds are deposited). Barley ( Hordeum vulgare L.) and vetch ( Vicia sativa L.) seeds were placed on TG with loam (TG-loam) and sand (TG-sand), and h of 0, -0.002, -0.006 MPa. Then, the imbibition curves were monitored. PEG experiments (0 to -2.5 MPa) were performed to estimate the critical h, h PEG , or h from which the imbibition curve decreases compared with that at 0 MPa. PEG curves for 0 > h > -0.01 MPa were compared with TG. Results PEG and TG curves were not different at 0 MPa. hPEG for barley and vetch was within [0, -0.01] MPa. While no differences were observed between PEG at [0, -0.01] MPa and TG-loam curves, TG-sand curves at -0.002 and -0.006 MPa were different to those of PEG. Conversely to PEG at -0.01 MPa, no imbibition was observed in TG-sand (-0.006 MPa). A negligible influence of h in TG-loam was observed. Conclusions PEG is not adequate to describe seed germination in soil. But the TG allows monitoring seed germination in real soils and controlled h.

Weed control in perennial crops is especially difficult in the first phases of crop establishment. Hydromulch is a pasty blend that hardens after application and has so far been used specifically for weed control for experimental purposes only. In this work we tested blends based on recycled paper, gypsum and lignocellulosic materials (wheat straw, rice husk and used mushroom substrate) applied in three different locations of Spain under peach, vine, almond and artichoke plantations compared with an untreated control, manual weeding and herbicide (only in artichoke). The most frequent weed species were annual and perennial forbs. Lower weed soil cover compared to the untreated control was still relevant between 333 and 456 days after mulching (DAM), depending on the trial. In the artichoke trial the weed control effect was similar to that obtained with herbicides until the end of the assessments. Annual forbs were satisfactorily controlled with hydromulches (highest for Lamium amplexicaule with an efficacy of 88% based on soil cover); mean efficacy of perennials such as Cyperus rotundus and Convolvulus arvensis was lower ranging between 30 and 74% efficacy depending on the trial. Multivariate analysis showed an increase in wind-dispersed species such as Conyza sp. and Lactuca serriola over time. The capacity of the mulches to reduce weed soil cover for around one year can be useful in crops where weed control is crucial during that time, such as in plant nurseries and new plantations. Future research could focus improving the durability of the mulches to extend this period.

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.

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 releves 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.

Context Field boundary (FB) establishment and conservation have been promoted to enhance biodiversity in agroecosystems. However, weeds can colonize these areas during the revegetation process, which might be a problem for adjacent fields. Data is necessary to facilitate acceptance of these structures by farmers. Objectives This work takes advantage of a unique opportunity to describe the plants establishing in a set of new FBs. The main aims were to describe species composition in a six-year period and to detect if FBs can be a weed source for surrounding agricultural land. Methods Data was collected in ten FBs in a semi-arid environment in north-eastern Spain (eight metres in width) created from 2003 to 2007 in a farm owned by the CITA Research Centre. Vegetation was recorded in spring in years 2006–08 and 2011–13 covering a time sequence that ran from establishment until an age of 10 years. The same data was recorded in adjacent winter cereal field centres (FCs) and existing boundaries of neighbouring commercial farms (CFBs) established decades earlier. Results Plant ground cover and total species richness increased rapidly in the FBs, remaining stable after approximately the fourth year. Different analysis confirm that vegetation in the FBs was different from that found in the FCs and CFBs; 10 years was probably a too short period for the FBs to develop a similar vegetation composition to that of the CFBs. Conclusions Data of this example support that establishing new FBs can promote plant diversity without infesting the surrounding fields with weeds.

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.

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.

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.

“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.

Spreading of hydromulch as a crop management technique might show important advantages over plastic films for weed control, because it can be applied anywhere in a field, even in orchard and vineyard rows. In the present work, 24 blends were prepared by mixing paper pulp, from recovered paper and cardboard coming from paper mills, with different additives: (a) wheat straw, rice hulls, and substrate used for mushroom cultivation on the one hand as fillers, and (b) rice bran, white glue, sodium silicate, and powered gypsum on the other hand as agglomerating agents. The blends were tested with a texture analyser to evaluate their mechanical properties, testing the puncture resistance (24 blends) and the tensile strength (15 blends). Scanning electron photomicrographs of some blends were obtained in order to explore the relationship between their components and the mechanical properties. The results indicate that a blend prepared with paper pulp, wheat straw sieved at 2.5 mm and gypsum attained the highest stress resistance and tensile strength. An environmentally controlled experiment was performed on this and another hydromulch in which rice husk substituted wheat straw to evaluate their efficiency for reducing weed seedling emergence, using propagules of four common summer weeds. Compared with the control treatment performed, the hydromulches reduced seedling emergence from 64.6% to 95.9%. In general, the percentage of dead seedlings underneath was greater than that which passed through the barrier, making the hydro mulches promising tools for preventing seedling emergence and for managing the weed seed bank in field conditions. (C) 2020 The Author(s). Published by Elsevier Ltd on behalf of IAgrE.

ResumenUna de las principales preocupaciones asociadas a la aparición de una nueva mala hierba invasora es la de evitar su expansión.En este trabajo se presentan los resultados de un estudio sobre las posibles vías de dispersión de teosinte (Zea mays ssp.) detectado en el Noreste de España en 2014.Se ha estudiado la distribución de los individuos de esta especie dentro de campos de maíz, así como la viabilidad de sus semillas despúes del proceso de molienda para pienso y en función de su tiempo de permanencia en purines de porcino y vacuno.Después de analizar la distribución de teosinte en 153 campos en Aragón y Cataluña, se ha encontrado que un 66,3 % de las parcelas han sido probablemente infestadas a través de las cosechadoras, confirmando que ésta es la principal vía de dispersión.La viabilidad de las semillas durante la molturación fue nula utilizando molinos con una criba de 5 y de 2,5 mm de diámetro (las comúnmente empleadas para la fabricación de pienso) aunque quedó viable un 2,6 % de las semillas cuando se utilizó una criba de 8 mm.Por último, el ajuste de los datos al modelo log-logístico indica que el tiempo de supervivencia medio de las semillas es de 11,1 y 16,4 días en purín de porcino y vacuno, respectivamente, y su nula viabilidad ocurre a los 15,7 días en porcino y 37,4 días en vacuno.Por tanto, hay que esperar al menos ese tiempo antes de esparcir ambos purines en zonas con infestaciones de teosinte.

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.

One of the main concerns associated with the appearance of a new invasive weed species is to prevent its expansion. In this paper we present the results of a study on the possible dispersal routes of teosinte (Zea mays ssp.) firstly detected in the Ebro valley (NE Spain) in 2014. With this purpose, the patterns of plant distribution within maize fields has been studied as well as the possibility of teosinte seeds remaining viable in the milling process for feeding animals and the viability of the seeds as a function of their residence time in pig and dairy slurry. After analyzing the distribution of teosinte plants in 153 fields in Aragon and Catalonia, it has been found that 66.3 % of the infested plots could have been probably infested by means of harvest combines. Regarding the milling and grinding process of grains of teosinte and corn together, null viability of seeds has been found using mills with an exterior mesh of 5 and 2.5 mm in diameter, which are commonly used for animal fodder but 2.6 % of the seeds remained viable after passing the 8 mm mesh. Finally, the log-logistic model predicted that the mean survival time of the seeds was 11.1 and 16.4 days in pig and cattle slurry, respectively and that the nil viability occurred at 15.7 and 37.4 days for pig and cattle slurry, respectively. It is, thus, necessary to wait at least during this period of time before spreading the slurry in areas with teosinte infestations.