Josef Soukup

• Professor
• Head of Department at Czech University of Life Sciences Prague

Integrated modelling of climate change impacts in the soil–plant–atmosphere system can improve agroecosystem resilience and resource use efficiency. For the research on tomato (Solanum lycopersicum L.), bell sweet peppers (Capsicum annuum L.), and winter oilseed rape (Brassica napus L.), the CSM-CROPGRO-Tomato, CSM-CROPGRO-Papper and CSM-CROPGRO-Ca...

Apera spica-venti, a prevalent weed in Czech winter wheat fields, has developed resistance to ALS-inhibiting herbicides due to their frequent use. This study reports a biotype of A. spica-venti resistant to pyroxsulam, with cross and multiple resistance to iodosulfuron, propoxycarbazone, pinoxaden, and chlortoluron. Dose–response experiments reveal...

Amaranthus retroflexus L. has recently become a problematic weed in CONVISO ® SMART sugar beet fields in the Czech Republic, largely due to the rapid adoption of this system and widespread application of ALS inhibiting herbicides in almost all crops, including other systems using ALS herbicide tolerant varieties. In this study, two A. retroflexus b...

Amaranthus retroflexus L. (redroot pigweed) is one of the most problematic weeds in maize, sugar beet, vegetables, and soybean crop fields in Europe. Two pigweed amaranth biotypes (R1 and R2) from the Czech Republic resistant to photosystem II (PSII)-inhibiting herbicides were analyzed in this study. This study aimed to identify the genetic mechani...

Systemic acquired acclimation and resistance are vital physiological mechanisms, essential for plants to survive challenging conditions, including herbicide stress. Harmonizing this adaptation involves a series of complex communication pathways. Hydrogen peroxide (H2O2) metabolism might play pivotal roles in orchestrating weeds’ acclimation and def...

Since 2023, a new format of the Common Agricultural Policy (CAP) has been implemented in Europe. Market forces alone cannot guarantee land services, which can be described as flows of goods and services from ecosystems to human systems as functions of nature. Market forces also cannot ensure food security everywhere and at all times, so deliberate...

There has been a longstanding and contentious debate about the future of glypho-sate use in the European Union (EU). In November 2023, the European Commission approved the renewal of the use registration for glyphosate for a further 10 years. Nevertheless, the EU Farm to Fork strategy calls for a 50% reduction in pesticide use by 2030. In November...

Rigid ryegrass (Lolium rigidum Gaud.) is one of the most troublesome weeds in Moroccan and Tunisian cereal crop fields. In total, 19 rigid ryegrass field populations were randomly selected in northern wheat crop areas of Morocco and Tunisia to examine the patterns of herbicide resistance to acetolactate synthase (ALS)- and acetyl-CoA carboxylase (A...

Omics techniques, including genomics, transcriptomics, proteomics, and metabolomics have smoothed the researcher’s ability to generate hypotheses and discover various agronomically relevant functions and mechanisms, as well as their implications and associations. With a significant increase in the number of cases with resistance to multiple herbici...

Bromus sterilis has evolved into a more predominant weed in the Czech Republic's winter wheat fields, owing largely to the widespread application of pyroxsulam for its management. In this study, we report a biotype that has developed resistance to pyroxsulam and has also shown cross-resistance to other herbicides. Although no differences in ploidy...

Soil-water practice is essential for farm sustainability, thereby establishing the reference level for agricultural policy of the European Union (EU). This paper focuses on the critical gap in the knowledge surrounding comparison of soil-water effects of Good Agricultural and Environmental Conditions (GAEC) and carbon farming. We aim to interrogate...

The continuous use of herbicides for controlling weeds has led to the evolution of resistance to all major herbicidal modes of action globally. Every year, new cases of herbicide resistance are reported. Resistance is still in progress in many species, which must be stopped before it becomes a worldwide concern. Several herbicides are known to caus...

Tripleurospermum inodorum (L.) Sch. Bip. is one of the most economically important and yield-reducing weeds in cereals in Europe. Random and systematic monitoring of this weed might provide an early warning for the farmers and slow down the pace of the evolution of herbicide resistance. This study aimed to identify resistant populations of T. inodo...

Understanding the impact of farming practices on the composition of weed communities has important implications for the sustainability of weed management strategies. This study analyses data from a 40-year experiment established at two sites in the Czech Republic in 1972. The impact of herbicide strategies on the weed communities was evaluated in m...

Although herbicides have been successfully used for controlling weeds, their continuous use has developed in the evolution of resistance to all major herbicide modes of action worldwide. Reports suggest that the members of Poaceae family are more prone to developing herbicide resistance than other families. In plants, epigenetic mechanisms play cri...

Brassica napus L. (oilseed rape) is known as one of the most important volunteer crops worldwide. Brassica napus volunteers can emerge for more than 10 years in subsequent crops. Three field experiments were carried out to compare the competitive ability and reproduction of conventional and Clearfield volunteer B. napus in spring barley under diffe...

The stability of three frying oils (rapeseed, sunflower, and rice) and their effect on the nutritional value of deep-fried fish fingers (FF) and potato croquettes (PC) was evaluated, considering the nutritional importance of reducing the amount of oil absorbed by fried foods. Ten frying cycles were performed for each food to mimic the repeated fryi...

Building on the agri-environment framework in Central and Eastern Europe, the article emphasizes the role and the use of the agri-environment in provision of different ecosystem services. It shows that relevant conservation measures with regard to ameliorating soil degradation contribute to the existence of sustainable land systems. In our study, w...

Investigation of molecular mechanisms of herbicide resistance to three modes of action was carried out in a population of Apera spica-venti with resistance to herbicides inhibiting acetolactate synthase (ALS), acetyl-CoA-carboxylase (ACCase) and inhibitors of photosystem-II (PSII). Greenhouse experiments were conducted to detect and characterize re...

Bromus sterilis is an annual weedy grass, causing high yield losses in winter cereals. Frequent use of herbicides had led to the evolution of herbicide resistance in this species. Mechanisms underlying herbicide resistance in B. sterilis must be uncovered because this problem is becoming a global threat. qRT-PCR and the next-generation sequencing t...

Although various studies of codon usage bias have been reported in a broad spectrum of organisms, no studies to date have examined codon usage bias for herbicide target genes. In this study, we analyzed codon usage patterns for the acetolactate synthase (ALS) gene in eight monocot weeds and one model monocot. The base composition at the third codon...

In this review, we aim to contribute to knowledge on renewable energy from the agricultural sector. Our focus is on understanding the environmental effects of maize, grass, and sorghum, which are used as raw material for biogas digestion. The reason why we focused on the energy prospects of these crops as potential diversification in ensuring viabl...

Bromus sterilis is an annual weedy grass, causing high yield losses in winter cereals. Frequent use of herbicides had led to the evolution of herbicide-resistance in this species. Mechanisms underlying herbicide resistance in B. sterilis must be uncovered because this problem is becoming a global threat. qRT-PCR and the next-generation sequencing t...

BACKGROUND Intensive application of acetolactate synthase (ALS)‐inhibiting herbicides has resulted in herbicide‐resistance in many weeds, including Bromus sterilis. The present study was conducted to identify the mechanisms conferring resistance to ALS‐inhibiting herbicides in a Bromus sterilis biotype. RESULTS Dose–response studies revealed the r...

Until now, the relationship between the fat and oil composition and their oxidation stability has been studied only at elevated temperatures (typically above 100 °C). Therefore, the initial oxidation rates of 19 edible fats and oils were determined as an increase in the peroxide value during storage in the dark at 35 °C with free access to air (oxy...

This article collated and interpreted data on land-based measures and capital investments support in Central Europe. Data collection is essential, due to more EU funds being distributed after 2020. Most evaluations focus on outcomes of agri-environmental measures within the most populous Member States. Unlike previous work, empirical data was hereb...

Couch grass (Elymus repens) is a morphologically diverse, rhizomatous, perennial grass that is a problematic weed in a wide range of crops. It is generally controlled by glyphosate or intensive tillage in the intercrop period, or selective herbicides in non-susceptible crops. The aim of this review is to determine the efficacy of non-chemical strat...

The main aim of the present study was to evaluate benefits of the new technology of sugar beet varieties tolerant to foramsulfuron (FSN) + thiencarbazone-methyl (TCM) herbicides commercialised as Conviso® Smart (four weed management strategies were tested) compared to conventional herbicides (two weed management strategies). Plot-field trials were...

Pyroxsulam and propoxycarbazone are known to inhibit acetolactate synthases in weedy plants. Partial sequence of acetolactate synthase from Bromus sterilis biotype resistant to pyroxsulam and propoxycarbazone has been deposited to NCBI GenBank database (MT113952.2).

The transboundary Prut River basin (PRB) is one of the most drought vulnerable areas in the Republic of Moldova, Romania, and Ukraine. The main objective of this study was to identify the response of hydrological drought to climatic conditions and cropping practice in a region with insufficient water resources. The presented work takes advantage of...

Three plot field trials (2014–2017) were carried out in Prague. The aim of the study was to evaluate the efficacy of herbicides against volunteers from Clearfield ® (CL) and conventional oilseed rape (Brassica napus L.) in winter wheat (Triticum aestivum L.) and to quantify the effect of herbicide and application time on wheat yield. Autumn control...

Precipitation and irrigation strongly affect herbicide management of vegetables, especial fast- growing vegetables as a kohlrabi. The objective of this study was to compare the effects of irrigation and paraffin oil-based soil adjuvant on the efficacy and selectivity of pendimethalin and metazachlor herbicides and their tank-mix combination in kohl...

The study is based on data from a long-term field experiment of extent and duration seldom found in weed science. Yield losses from weed infestation of individual crops and crop rotations were studied in a field trial conducted since 1972 at two sites in the Czech Republic. The ongoing trial comprises multi-crop and simple crop rotations with 50 an...

The efficacy of different frequently used selective herbicides and their impact on weed community were assessed in the field experiment with cereal crop rotation in 2013–2016. All herbicide treatments provided effective weed control, but community composition changed after 4 years. The density of many weed species increased on the untreated plots....

Reliable tests on herbicide resistance are important for resistance management. Despite well-established greenhouse bioassays, faster and in-season screening methods would aid in more efficient resistance detection. The feasibility of a chlorophyll fluorescence agar-based test on herbicide resistance in Apera spica-venti L. was investigated. Herbic...

The main objective of this study was to project changes in the evolution of drought characteristics (frequency, duration and magnitude) during the 21st century in lowlands, highlands and mountainous regions in the Czech Republic (CR). We focused on the multi-scalar nature of droughts as a function of the variables that govern the balance of moistur...

Wide deployment of genetically modified herbicide-tolerant (GMHT) maize may affect the efficiency of weed control methods and impair ecosystem functioning. We examined these potential threats using glyphosate-tolerant maize NK603 (Monsanto Technology LLC, St. Louis, MO, USA) planted in 54 randomly distributed plots in 2013 and 2014. Maize was grown...

The efficacy and selectivity of herbicides and tank-mix combinations at different application terms in Clearfield and ExpressSun sunflowers were evaluated. Five-plot field trials (2011–2015) were carried out in Prague. The efficacy of tribenuron (TBM) was excellent and quite rapid on Chenopodium album. Its efficacy on other tested dicot weeds range...

Barren brome (Bromus sterilis L.) is a troublesome weed of winter cereals in western and central Europe and its control requires an exact estimation of emergence time. The study focused on the germination response of populations from the Czech Republic to water availability at different temperatures and under different light regimes. Seeds were abl...

We compared application of conventional herbicide and two herbicide strategies used in glyphosate-tolerant crops. We observed weed control efficiency and effect on beneficial epigeic arthropods.

Cytoplasmic male sterility (CMS) allows efficient biological confinement of transgenes if pollen-mediated gene flow has to be reduced or eliminated. For introduction of CMS maize in agricultural practice, sufficient yields comparable with conventional systems should be achieved. The plus-cultivar-system in maize offers a possibility for biological...

Bromus species are annual winter weeds from the Poaceae family which have become troublesome weeds of winter cereals. The herbicides propoxycarbazone and pyroxsulam are widely used for control of B. sterilis. The objective of this study was to determine the effect of different types of adjuvants and carriers on the efficacy of pyroxsulam and propox...

Background: Lettuce (Lactuca sativa L.) is a crop that is very sensitive to herbicide contamination owing to its short growing season. The use of long-residual herbicides and non-woven fabric coverings could therefore influence pendimethalin concentrations in soil and lettuce. Results: The pendimethalin half-life in soil ranged between 18 and 85...

The response of field-grown vegetables to adverse weather conditions is strongly coupled to the timing of adverse events, the sensitivity of the growth stage of the impacted crop and the management actions that are taken. To estimate the long-term yield response to changes in temperature and precipitation as well as the short-term response to key a...

El estudio se centra en los perjuicios causados por las sequías sobre los cultivos en las regiones bajas de la República Checa. Grandes pérdidas en los cultivos se han atribuido a las sequías, a menudo en combinación con el calor y otros tipos de estress. El objetivo de este trabajo fue investigar el efecto de las sequías cuantificado mediante el Í...

The objective of this study was to com pare the effect of nonwoven fabrics used for growth acceleration in lettuce on the efficacy and selectivity of pendimethalin herbicide at varying application rates. Small plot experiments were conducted with head lettuce in Prague, Czech Republic during 2011–2013. Herbicide efficacy was higher in plots covered...

This study presents a detailed analysis on the role of snow cover during the cold season (October–March) on soil moisture deficit and drought development during the growing season (April–September) in the lowland and highland sites in the Czech Republic. Besides daily, weekly and seasonal series of basic snow-cover characteristics [the first day an...

This research aimed to identify an approach for adaptation of agriculture to increased climate variability and projected changes, taking into account regional specificity of climate change. Changes in the timing of growing season (GS) parameters for both observation and models data were computed using daily mean temperatures for three thresholds th...

We ranked the most frequently used pre-emergent herbicides in sunflower (Helianthus annuus) according to their efficacy and selectivity under different soil moisture conditions within 2008–2011. The efficacy of oxyfluorfen, aclonifen, acetochlor, dimethenamid, and propisochlor on the majority of weeds (Chenopodium album, Echinochloa crus-galli, Ama...

Crop loss due to drought is a complex issue, because it changes according to the drought intensity and duration, and the developmental stage of the plants when drought occurs. In order to assess the drought-induced decline in crop harvest, drought variability and the yield sensitivity of winter wheat, maize, sugar beet, and sunflower to drought dur...

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 th...

This paper reports on the within-habitat (α) and on the between-habitat (β) diversity of weed vegetation on arable land in the Czech Republic, influenced by management systems, crops grown and altitude. A phytocoenological survey was conducted from 2006 to 2008 during a vegetation period using relevés that were 100 m2 in size, placed in the central...

In this study we investigated the influence of drought on crop productivity and, in particular, the drought time-scales that affect the growth of eleven agricultural crops with growth cycles of different lengths in the Czech Republic. In addition, the performance of the standardised precipitation evapotranspiration index (SPEI) at various lags for...

The aim of this work is to describe the differences in sensitivity of Clearfield, ExpressSun and non-herbicide tolerant (HT) sunflower cultivars to several acetolactate synthase inhibitor herbicides and to find out the differences in sensitivity in F1 and F2 generations of these cultivars. Non-HT sunflower was very sensitive to most of the tested h...

Monitoring of field emergence of selected weeds important in sugar beet stands was carried out in 2001-2011 during the growing season (from March to November) in two locations in the Czech Republic. High level of field emergence of Avena fatua, Chenopodium album, Mercurialis annua, and Abutilon theophrasti was recorded during March and April. In ye...

This study investigates the mechanisms of resistance to acetolactate synthase-inhibiting herbicides in populations of Apera spica-venti (L.) P.B. from the Czech Republic. The proportion of resistance due to mutant acetolactate synthase (ALS) alleles was estimated by genotyping individuals from each of three populations for the eight ALS mutations k...

This paper reports on the current situation in weed vegetation composition on arable land in selected areas of the Czech Republic, assessment of influence of selected variables: applied management systems (conventional, organic), crops (winter cereals, root crops) and altitude and ranking of the importance of these particular factors. A phytocoenol...

This study has, for the first time, analyzed the potential impacts of climate change on damaging frost during growing season of vegetable crops at a high horizontal resolution of 10 x 10 km in the Bohemian Plateau. The main objective of this study was to assess the potential changes in the timing of the last spring frost, the first autumn frost for...

This study has, for the first time, analysed in detail the risk occurrences of the last spring frost, first fall frost and the length of the frost-free period during the growing season of vegetable crops at a high horizontal resolution of 10 km in the Elbe River lowland in the Czech Republic. The daily minimum air temperature from 116 grid points t...

Cyperus esculentus (yellow nutsedge) belongs to the world most important weeds on arable land. This species is classified as an invasive one in Central and North-western Europe. It is not yet present as a weed in the Czech Republic, but its occurrence in neighbouring countries and its ability to survive winters in this region must be taken into acc...

Bromus sterilis L. (barren brome) has become a troublesome weed of winter cereals in reduced tillage systems, mainly in South and North America, middle and Western Europe. In the Czech Republic, its importance has increased dramatically over the past 10 years. Barren brome is reported as a problem weed in other winter crops such as oil seed rape, i...

Prunus avium species of the Rosaceae family exhibit gametophytic self-incompatibility. Determination of the self-incompatibility genotype of individuals is essential for genetic studies and the development of informed management strategies. The PCR-based detection of S-allele helps to promote and speed up traditional breeding activity and hence mol...

This study has, for the first time, analyzed in detail the risk occurrences of the last spring frost, first fall frost, and the length of the frost-free period during the growing season of vegetable crops at a high horizontal resolution of 10 km (CZGRIDS, ALADINClimate/ CZ) in the Elbe River lowland. The daily minimum air temperature from 116 grid...

This article documents the impact of site conditions and farming practices on the occurrence of rare and endangered weeds on arable land in the Czech Republic. A survey was conducted between 2006 and 2008 in winter cereals, spring cereals and wide-row crops. The relationship between the occurrence of plants and explanatory factors was analysed usin...

Climate change could promote the altitudinal spread of C4 weed species since they can benefit from warmer climate. The effects of altitude and climatic conditions (the sum of temperatures above 5°C and precipitation) on the biomass and seed production of two annual C4 weeds – Amaranthus retroflexus L. and Echinochloa crus-galli (L.) P. Beauv. – wer...

Current weed spectrum on arable land in the Czech Republic was analyzed and constancy for the individual species determined. Phytocoenological survey was conducted within 2006–2008 on 62 farms. The choice of field selection for sampling was winter cereals, spring cereals, and wide-row spring crops. In the central part of each field phytocoenologica...

The aim was to compare the efficacy, selectivity to sunflower and dissipation of three chloracetamide herbicides (acetochlor, metolachlor and pethoxamid) in dependence on precipitation after application. A small plot field trial was carried out with sunflower in Central Bohemia in 2010 and 2011. The remaining concentration of active ingredient in t...

Weeds can grow very well in sugar beet stands and if they are not controlled, the yield can decrease dramatically. In the Czech Republic, a system of several (normally three) post-emergent herbicide applications is currently used. For particular terms of application, herbicides and their rates are chosen according to weed spectrum and growth stages...

Adjuvants are surface active agents that are added to pesticide formulations or tank-mix to facilitate the mixing, application, or efficacy of these products. Addition of adjuvants changes the physico-chemical properties of spray liquid. In this work, we have focused in particular on surface tension and density of aqueous solutions of different adj...

The biological characteristics of a crop together with the way it is managed in the field determine the rate at which genetic material moves by seed and pollen between crops, crop-derived weeds (volunteers), feral plants, and wild relatives. The EU FP6 project, SIGMEA, collated and compared data on the transmission of genetic material in relation t...

Vráblík A., Hodek J., Soukup J., Demnerová K., Ovesná J. (2012): Development and verification of PCR based assay to dectect and quantify garden pea lec gene. Czech J. Food Sci., 30: 247–257. Genetically modified organisms (GMOs) entering the food chain have became its part, which is necessary to monitor. GMO analyses are used as a control mechanism...

Two multi-scalar drought indices, the Standardized Precipitation Index (SPI) and the Standardized Precipitation–Evapotranspiration Index (SPEI), were used to study secular drought evolution from 1901 to 2010 in the lowland regions of the Czech Republic. To assess the temporal patterns of droughts as multi-scalar events, the SPEI and SPI were calcul...

The aim of this work was to determine the effect of different adjuvants on phytotoxicity of flumioxazin on sunflower. Highest selectivity to sunflower was found in flumioxazin without adjuvant (phytotoxicity 8-25%). Symptoms of flumioxazin phytotoxicity were growth inhibition and leaf necroses. All tested adjuvants increased phytotoxicity of flumio...

Four efficacy and selectivity small plot field trials were carried out in four sunflower hybrids at two localities in Middle Bohemia during 2008 and 2009 with herbicides containing the active ingredients flumioxazin and fluorochloridone. For Chenopodium album, an efficacy of 97% was found after pre-emergent application of fluorochloridone + acetoch...

Herbicide efficacy is influenced by many environmental factors. The knowledge of relations between environmental factors and herbicide efficacy is very important when choosing the herbicide, its dose or proper adjuvant. As for meteorological factors, especially precipitation, air and soil moisture, temperature, intensity of solar radiation, and win...

Adoption of HT crops can mean easier weed management especially in those crop stands where chemical weed control can be limited and weed management complicated. In the case of selected herbicides (ALS and ACC-ase inhibitors), methods of conventional breeding were used to get hybrids showing herbicide tolerance. In breeding glyphosate and glufosinat...

Herbicide tolerance allows a specific crop variety to survive a herbicide treatment without injury despite the fact that the herbicide cannot be used selectively in a common variety of the same crop. Widely adopted and used worldwide are genetically modified herbicide tolerant (GMHT) crops with tolerance to the non-selective herbicide active ingred...

Selectivity is the ability of herbicides to be toxic to selected plant species without causing toxic effects to the other ones. There are high differences among herbicides in their selectivity to crop species. Herbicide selectivity is based on different mechanisms that can be combined. The most common mode of selectivity is based on physiological a...

A survey of weeds in European maize crops was carried out. The survey was based on the response to a questionnaire sent to maize specialists in 11 countries asking for information about weed occurrence in maize crops before weed control is carried out. The contribution could be in the form of 1) a recently performed survey of weeds in maize, 2) an...

Over the last decades, the appearance of herbicide resistance in plants has not been supposed to involve and therefore was not taken seriously. Later on, more cases of resistant populations were reported. Since then, numbers of cases have continued to rise and by this year more than 200 weed resistant species had been confirmed. In this contributio...

The growth regulator herbicides are synthetic chemicals acting as auxin-type phytohormones. Application of growth regulator herbicides promotes the disbalance in phytohormone levels in the sensitive plants resulting in metabolic defects and disruption of normal plant growth. The majority of growth regulator herbicides are relatively fast uptaken by...

Velvetleaf is one of the most significant and fastest spreading alien weeds in Europe, and it is a difficult weed to control in conventional sugarbeet. Laboratory experiments were carried out in 2007 and 2008 and field experiments were carried out in 2006, 2007, and 2008 with the aim of finding effective herbicide combinations and optimum timing of...