Jose L. Gonzalez-Andujar

Spanish National Research Council | CSIC · Department of Crop Protection (IAS)

One of the crucial issues in developing nations is diminishing the yield gaps. Therefore, accurate yield gap estimation has many real-world uses for increasing crop production. Utilizing comparative performance analysis (CPA) techniques, the yield gap of wheat fields was evaluated in this study. In Varamin, Tehran Province, Iran, data on 104 wheat...

In every agricultural system, weed seeds can be found in every cubic centimeter of soil. Weed seeds, as a valuable trait underlying the fate of weed populations, exhibit differing levels of seed dormancy, ensuring their survival under uncertain conditions. Seed dormancy is considered as an innate mechanism that constrains germination under suitable...

Weed community structure, including composition, taxonomic and functional diversity, may explain variability in crop quality, adding to the variability accounted by management, climatic and genetic factors. Focusing on Mediterranean rainfed wheat crops, we sampled weed communities from 26 fields in Spain that were either organically or conventional...

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 researc...

In every agricultural setting, weed seeds can be found in every cubic centimeter of soil. Weed seeds, as a valuable trait underlying the fate of weed populations, exhibit differing levels of seed dormancy, ensuring their survival under uncertain conditions. Seed dormancy is considered as an innate mechanism that constrains germination under suitabl...

For a successful germination and plant growth, seeds must germinate at the right time. Seeds must become nondormant and must fulfill the seed germination requirements. These requirements include light/dark, moisture, temperature, and other environmental cues (e.g., ethylene, exudate from host roots, or chemicals from fire) in the habitat. Seeds com...

Avena sterilis L. ssp. sterilis es una maleza problemática de los cereales de invierno tanto en su área de distribución nativa que abarca el Mediterráneo hasta el sur de Asia, como en las regiones de América, el norte de Europa y Australasia donde ha sido introducida. Una mejor comprensión de los patrones de emergencia de las plántulas de esta male...

Perennial woody crops span over a broad variety of species in Europe with olive and vine being the most cultivated tree crops. Nowadays, the increasing problem of herbicide resistance, the possible withdrawal of herbicides from the EU market and their effects on farmland biodiversity are driving a need to change weed control practices. Therefore, a...

Avena sterilis subsp. sterilis (sterile oat) is a troublesome grass weed of winter cereals both in its native range encompassing the Mediterranean up to South Asia, and in regions of America, Northern Europe and Australia where it is introduced. A better understanding of seedling emergence patterns of this weed in cereal fields can help control at...

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...

Herbicide resistance can affect seed germination and the optimal conditions required for seed germination, which in turn may impose a fitness cost in resistant populations. Winter wild oat [Avena sterilis L. ssp. ludoviciana (Durieu) Gillet and Magne] is a serious weed in cereal fields. In this study, the molecular basis of resistance to an ACCase...

The objective of this study was to explore the physical properties of maize seeds in competition with weeds. The basic and complex geometric characteristics of seeds from maize plants, competing with Datura stramonium L. (DS) or Xanthium strumarium (XS) at different weed densities, were studied. It was found that the basic and complex geometric cha...

Aim of study: A predictive model of the seedling emergence pattern of Phalaris brachystachys Link (short-spiked canary grass) was developed, aimed to contribute to support a more efficient management of this troublesome, competitive weed in winter cereal crops around its native Mediterranean range and in different areas of the world where it is int...

Population models are particularly helpful for understanding long-term changes in the weed dynamics associated with integrated weed management (IWM) strategies. IWM practices for controlling L. rigidum are of high importance, mainly due to its widespread resistance that precludes chemical control as a single management method. The objective of this...

Tubers are the main means of propagation in purple nutsedge (Cyperus rotundus L.), one of the most troublesome weeds competing in crop and pasture systems throughout the world. Tuber sprouting is highly linked to temperature, the main environmental factor limiting the growth of purple nutsedge. In the present study, a new thermal time model was dev...

Italian ryegrass (Lolium multiflorum L.) is a highly competitive weed widely disseminated worldwide that affects both summer and winter crops. The development of predictive emergence models can contribute to optimizing weed management. The aim of this study was to develop and validate an empirical emergence model of Italian ryegrass based on soil t...

Concerns about a global decline in pollinators have called for more knowledge about the factors influencing wild pollinator abundance and diversity in agroecosystems. Agricultural intensification has been identified as the main cause of this “global pollinator crisis”, particularly due to reductions in natural areas holding critical floral and nest...

Italian ryegrass ( Lolium multiflorum L.) has become notorious due to glyphosate resistance evolution. To study the demography of susceptible and glyphosate-resistant Italian ryegrass populations, several experiments were conducted in the grower’s field to evaluate seedling emergence, survival and reproductive traits patterns in three cohorts, and...

Within-field demography of weeds exhibiting wind-mediated long distance seed movement can be largely governed by extra-field seed-source populations. Thus, for these species, a clear understanding of the temporal and spatial patterns of seed dispersal can benefit the development of effective management options. The spatial distribution of the seeds...

“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 co...

In weed science and management, models are important and can be used to better understand what has occurred in management scenarios, to predict what will happen and to evaluate the outcomes of control methods. To-date, perspectives on and the understanding of weed models have been disjointed, especially in terms of how they have been applied to adv...

Decision support systems (DSSs) are computer programs that, by using expert knowledge, simulation models and/or databases, are of assistance in the decision-making process as they offer management recommendations and/or options. The principal aim of a DSS is to improve the quality, speed and effectiveness of decisions. Since their beginnings in the...

AvenaNET and VallicoNET are web-based DSS developed for Lolium rigidum (ryegrass) and Avena sterilis spp. ludoviciana (winter wild oat) control in Spanish dryland cereals. This chapter describes the rationale, structure and evaluation of these DSS. Both systems present a common structure that contains an interface, a database and a bioeconomic mode...

Weed management Decision Support Systems (DSS) are increasingly important computer-based tools for modern agriculture. Nowadays, extensive agriculture has become highly dependent on external inputs and both economic costs, as well the negative environmental impact of agricultural activities, demands knowledge-based technology for the optimization a...

IWMPRAISE is the first EU Framework Research project focusing solely on weed management. Thirty-eight partners in eight European countries are working together on developing integrated weed management strategies for agricultural and horticultural crops. Per Kudsk, the coordinator of IWMPRAISE, and the work package leaders present the project, the o...

Discusses mathematical modeling as an excellent framework for weed management Addresses integrated weed management tactics from both operational and strategic time planning perspectives Assesses the environmental impact of different weed control interventions Weed management Decision Support Systems (DSS) are increasingly important computer-based t...

Arable field margins are valuable habitats providing a wide range of ecosystem services in rural landscapes. Agricultural intensification in recent decades has been a major cause of decline in plant diversity in these habitats. However, the concomitant effects on plant functional diversity are less documented, particularly in Mediterranean areas. I...

Junglerice (Echinochloa colona) is one of the most important annual weeds affecting crops in Argentina. A predictive seedling emergence model based on thermal time was developed and validated. Monitoring of seedling emergence was performed weekly during the growing season in a soybean field over four years. Cumulative thermal time, expressed in gro...

Good weed management relies on the proper timing of weed control practices in relation to weed emergence dynamics. Therefore, the development of models that predict the timing of emergence may help provide growers with tools to make better weed management decisions. The aim of this study was to validate and compare two previously published predicti...

In 2019, the ENDURE network launched a survey on the agricultural use of glyphosate in European countries. This report presents the results obtained through the survey and proposes a framework for understanding and monitoring glyphosate uses. The share of herbicides among all pesticide sales varies from one country to another. It is particularly hi...

In this work, we aimed to test whether taxonomic diversity and functional diversity and the values of functional traits of the weed seed bank varied across the field, from margins to the core, and between fields embedded in distinct landscape structures. We sampled the seed bank of 47 conventionally managed cereal fields from two Mediterranean regi...

Italian ryegrass (Lolium multiflorum L.) is an annual grass widely distributed in cultivated crops around the world. This weed causes significant yield reduction in many crops and has developed herbicide resistance. The aim of this study was to develop a cohort-based stochastic population dynamics model that integrates both emergence (thermal time)...

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research sp...

Weed scientists are usually interested in the study of the distribution and density functions of the random variable that relates weed emergence with environmental indices like the hydrothermal time (HTT). However, in many situations, experimental data are presented in a grouped way and, therefore, the standard nonparametric kernel estimators canno...

The bioeconomic models developed in Weed Science consider the effect of a species on the crop. Bioeconomic models accounting for species interactions within the weed community might represent more realistic approximation to the economic outcome of weed control options in Mediterranean cereal crops. A bioeconomic model, based in community dynamics,...

Boundary structure can hinder or facilitate disturbance of the boundary vegetation by farming practices, such as herbicide and fertiliser drift and occasional cultiva- tion; this may affect their potential role as a weed reser- voir. It would be relevant for researchers, farmers and legislators to know whether relationships exist between boundary s...

Justificación – Marco de referencia La protección de cultivos es un fenómeno complejo donde la toma de decisiones tiene una dimensión fundamental. Dentro de este contexto, la predicción es clave para que las decisiones de los productores y técnicos sean tomadas adecuadamente. Para realizar buenas predicciones ha emergido en el mundo científico la...

Hairy vetch (HV, Vicia villosa Roth) is a winter annual legume cultivated for pasture grazing, in crop rotations with cereal crops under semi-arid conditions. The inclusion of HV increases soil nitrogen, thus contributing to satisfied the nutrient requirements of the successive crops. As a forage crop, HV shows a remarkable capability for natural r...

Weeds can harm crop growth and yield by competing for light, water, and nutrients and can produce high global potential yield losses if not controlled. However, the effects of weed diversity have not been fully examined. Here, we have used long-term data (31 years) of a cereal–legume rotation from a locality in central Spain to determine the import...

A Web Decision Suport System (SSD Manzano) for the diagnosis and control of pests in apple orchards was evaluated from the practical and educational viewpoints. The system was implemented twelve years ago and since has been extensively used as a support tool to take decisions and education training. Basically, the system is built up of three differ...

Weed species contribute to plant diversity in agroecosystems and the functional structure of their communities could relate to keyfunctions like crop biomass production. In non-agricultural systems, it has been suggested that under processes constraining func-tional diversity, community weighted mean values (CWM) represent the optimal local trait s...

Weed species are crop accompanying flora and they have been regarded as organisms that compete for resources negatively affecting crop performance. Nonetheless, in recent years, their role in maintaining agroecosystem diversity and function is starting to be uncovered. The structure of weed communities is the result of management practices, climate...

Weed species present high competitive capacity, rapid adaptability and herbicide resistance, hindering their effective control across worldwide cropping regions. Since field-conducted experiments are very time-consuming and usually expensive, mathematical population-based models are valuable tools to test and develop long-term weed management progr...

Uno de los mayores retos de la humanidad para el siglo XXI es cubrir la demanda de alimento ante una población mundial en crecimiento con recursos limitados y amenazada por el cambio climático. La agricultura es una fuente directa de alimentos y biocombustibles. Iberoamérica es hoy un polo de producción agraria en crecimiento y expansión. En las úl...

Background: Pallenis spinosa (Asteraceae) produces both winged and wingless achenes. Both achene morphs are non-dormant and show a similar embryo size, rendering dispersal ability as their only apparent functional difference. Aims: We studied morph-specific release and spatial dispersal patterns to ascertain whether the common view of seed dimorphi...

Compared to classical, only-one weed species models, demographic projections accounting for species interactions within the weed community might represent a more realistic approximation to the outcome of weed control options in Mediterranean cereal crops. A mathematical model for simulating the dynamics of a weed community composed of populations o...

Management practices and other environmental conditions may represent important filtering processes and constrains on the assembly of weed communities. This could be in accordance with evidences showing weed community weighted mean trait values (CWMs) varying along environmental gradients. If this is the case, CWMs may represent the optimal weed st...

Spatial aggregation has been suggested as one of the mechanism permitting the coexistence of plant species. This mechanism could also explain the maintenance of diverse competitive strategies in weed communities. In that case, spatial aggregation of conspecific individuals would benefit weaker competitor weed species, whereas stronger competitors w...

Background Integrated Weed Management (IWM) typically involves complex risk management decisions. It comprises preventive and control measures that require decisions on crop choice and sequence, cover cropping, fertilisation, cultivation type and frequency. IWM can therefore not be considered a set of weed control tactics alone, it is a complex sys...

This study presents a simple landscape model of the influence of seed dispersal on weed population dynamics between fields. In the model, three fields are interconnected through weed seed dispersal, where seed might move with field equipment, in irrigation water or may be wind‐dispersed. The model is intended to characterise the impact of field‐lev...

Conyza bonariensis is an invasive weed of increasing importance in subtropical and warm-temperate regions worldwide, both in non-agricultural habitats and in annual and perennial crops, especially under no-till management. To gain insigths on basic life cycle processes determining the demographic success of C. bonariensis, we studied for this speci...

Volunteer canola (Brassica napus L.) can damage the production of subsequent canola crops and other crops. Timely and more accurate control could be developed if there is a better understanding of its temporal emergence patterns. The objectives of this study were to develop and validate a predictive model of emergence for B. napus under semi-arid c...

Lolium rigidum Gaud. is the most prevalent and damaging grass weed of winter cereals in Spain. L. rigidum infestations are frequently treated with herbicides and, consequently, populations have evolved resistance. In 2012–2013 a random survey was conducted across cereal cropping areas of the Castilla-León and Cataluña regions to establish the distr...

Southern South America is expected to play an increasingly important role in global food production, but climate change could seriously threaten it. Here we have analysed long-term historical data for major crops (rice, oats, barley, sunflower, soybean, sorghum, wheat, maize) at subnational scale to (a) look for common features among crop yield dyn...

Phelipanche aegyptiaca is one of the most important parasitic weeds in some crops including potato. P.aegyptiaca reduces potato tuber size and can produce severe yield losses. The development of predictive models can be useful to help managers to choose the best management options and times and, thereby, improve weed control.The objective of this s...

Agricultural field margins are often recommended as a cost-effective and efficient method for wild bee conservation, in response to the threat imposed by global pollinator declines as a result of intensive agricultural practices. In this study we compared margin characteristics and wild bee community structure from sites with landscapes of varying...

Seed biology is important for emergence in the field and for future weed infestations. This chapter focuses on seed biology, germination, dormancy and efforts in predicting weed emergence from seeds from a European perspective. It presents a brief overview of population dynamics in time and space, the factors influencing the dynamics and how popula...

Avena fatua and Descurainia sophia are two important annual weeds throughout winter rapeseed (Brassica napus L.) production systems in the semiarid region of Iran. Timely and more accurate control of both species may be developed if there is a better understanding of its emergence patterns. Non-linear regression techniques are usually unable to acc...

Managing production environments in ways that promote weed community diversity may enhance both crop production and the development of a more sustainable agriculture. This study analyzed data of productivity of maize (corn) and soybean in plots in the Main Cropping System Experiment (MCSE) at the W. K. Kellogg Biological Station Long-Term Ecologica...

Seedling emergence is one of the most important phenological processes that influences the success of weed species. Therefore, predicting weed emergence timing plays a critical role in scheduling weed management measures. Important efforts have been made in the attempt to develop models to predict seedling emergence patterns for weed species under...

La interrelación entre la agricultura y la Biometría se remonta a principios del siglo XX. La agricultura ha jugado un papel impulsor en el desarrollo de la biometría. Se puede afirmar en este sentido que la agricultura ha jugado el mismo papel como motor del desarrollo de la estadística, que la física en relación con las matemáticas. La agricultur...

Parametric nonlinear regression (PNR) models are used widely to fit weed seedling emergence patterns to soil microclimatic indices. However, such approximation has been questioned, mainly due to several statistical limitations. Alternatively, nonparametric approaches can be used to overcome the problems presented by PNR models. Here, we used an eme...

El presente trabajo pretende aportar una información descriptiva sobre la composición florística de los márgenes de campos de cereales de secano en Andalucía y sobre la abundancia y diversidad de abejas asociadas a los mismos. Esta información puede servir de base para el diseño de estrategias de conservación de márgenes que permitan mantener pobla...