23 research outputs found
Herbicide resistance in weeds: early detection, mechanisms, dispersal, new insights and management issues
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Herbicide resistance in weeds: early detection, mechanisms, dispersal, new insights and management issues
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Impact of Seed Priming Technologies on the Agronomical Characteristics of <i>Lathyrus sativus</i> L. Commercial and Local Variety Under Normal and Saline Conditions
No full textOne of the main abiotic factors affecting agricultural productivity in semi-arid regions is salinity. Seed priming is a frequently used method to enhance plant growth under saline environments. The aim of this work was to demonstrate the differences in eight agronomical characteristics of two grass pea varieties under two salinity regimes (80 and 160 mM NaCl) when pre-exposed to seed priming (hydropriming, biopriming with Bacillus subtilis and their combination). The two varieties responded well to the priming treatments, with more beneficial effects monitored for the local variety. Evaluating the root characteristics that are most affected by stress, it was found that, at 80 mM NaCl, the combination of biopriming and hydropriming increased the fresh root weight by 36.8% and root length by 70% in the commercial variety, and by 124% and 47%, in the local variety, respectively. At 160 mM NaCl, biopriming increased the fresh root weight by 40.3% and root length by 50.3% in the commercial variety, while in the local variety, the combination of biopriming and hydropriming increased the fresh root weight by 124% and root length by 47%, respectively. Overall, biopriming and the combination of biopriming and hydropriming significantly enhanced plant growth characteristics of the two grass pea genotypes
Editorial: Precision information identification and integrated control: pest identification, crop health monitoring, and field management
No full textWeed competitive ability of faba bean (Vicia faba), pea (Pisum sativum), and vetch (Vicia sativa) crops under semi-arid conditions
No full textAgricultural practices must adapt to address new climatic conditions and the rising global demand for food. Among these practices, cultivating crops resilient to various stresses while maintaining productivity—such as annual legume crops—is essential. This study aims to assess the competitive interactions between legume crops and weeds. Field experiments were conducted using a Randomized Complete Block design with three replicates. Six weed treatments, representing the presence and absence of weeds (utilizing natural weed communities) were applied as the main plots for each of three-grain legumes: pea (Pisum sativum), faba bean (Vicia faba), and vetch (Vicia sativa), under semi-arid Mediterranean conditions. To evaluate the crops' competitive abilities, weed and crop biomass were collected at 3, 6, and 9 weeks after sowing (WAS). Additionally, pod yield was measured for each species to determine crop yield. The results indicated that faba bean exhibited the strongest growth competition, sowing: a) the smallest difference in final (9WAS) biomass between weedy and weed-free treatments compared to peas and vetch (30, 55, 57% reduction, respectively), and b) significant benefits in continuous removal of weeds in peas, vetch as compared to the no-benefits in such treatment in faba beans. In terms of yield tolerance to weed competition, peas demonstrated the greatest resilience, followed by faba beans and vetch (24, 38, 76% reduction, respectively). The timing of the manifestation of the crops' suppressive abilities varied: in peas and vetch, there was no measurable effect on growth due to the weed competition at the early and medium stages (at 3 and 6WAS) of crop development but only at the late stage (9WAS). Given the importance of grain legumes and the limited research on their competitive interactions with weeds, further studies are needed to promote more sustainable agricultural practices
Factors affecting seed germination and emergence of Venice mallow (Hibiscus trionum)
No full textVenice mallow is an emerging weed problem in many regions of the world in various crops. Studies on its hard seed coat were conducted by scanning electron, light, and fluorescence microscopy. The effects of environmental factors on germination and seedling emergence were examined in laboratory experiments. Seeds possessed physical dormancy (90%) that required immersion for 0.5 h in concentrated sulfuric acid to break without damaging the seed. After scarification, 29% of seeds exhibited primary embryo dormancy. Exposure of seeds to even short periods of 15 d of prechilling induced secondary dormancy (10% germination). The surface of hard seeds had a velvety appearance from numerous papillate structures and deposits (hydrophilic material). The location of the water barrier was very superficial in the outer seed coat. Although, in hard seeds, the hilar area appeared to have vertical ruptures and the hilum fissure appeared to be open, there was no water entry. It was observed that microruptures could be the region of structural weakness of hard seeds in relation to water permeability during prolonged burial (8 mo). The highest (60%) germination was recorded at a day/night temperature of 30/20 C with a 12-h photoperiod. No germination was measured at either 10 or 45 C constant temperature. Germination was recorded with a broad range of pH (3-11) and seeds were rather tolerant to low water potential (20% germination at -1.2 MPa). Seedling emergence was higher for seeds buried at 2 cm than for those placed on the surface (54 vs. 38%, respectively). These results showed that Venice mallow is a rather unique species that possesses a complex mechanism of dormancy (physical, primary, and secondary). Information gained in this study will be used in developing management strategies for this species
Involvement of Epigenetic Mechanisms in Herbicide Resistance: The Case of Conyza canadensis
No full textGlyphosate is the most important herbicide globally, and horseweed (Conyza canadensis) has been one of the most commonly encountered weed species that has developed resistance to it in various parts of the world, including Greece. After glyphosate application, horseweed populations show a wide range of phenotypic plasticity in response to selection pressure. In previous work, we have proposed a herbicide resistance mechanism that is not due to a point mutation at the codon 106 of EPSP synthase but most likely due to a synchronized overexpression of EPSPS and the ABC transporter genes. In the current study, it is hypothesized that the observed phenotypic alterations and differential expression of the EPSPS gene could be attributed to epigenetic changes. DNA methylation plays a pivotal role in many biological procedures such as gene expression, differentiation, and cellular proliferation. Sodium bisulfite sequencing was used to detect epigenetic changes that occur at the C5 position of cytosine residues within CpGdi nucleotides in two horseweed populations (resistant vs. susceptible). Results show differential methylation pattern between the two populations. This work will elucidate the naturally increased resistance of C. Canadensis to glyphosate and set the bases for future development of techniques that restrict weed resistance to herbicides
Integrated weed management in long-term maize cultivation
No full textThe effects of different measures within maize cropping technology, aimed to suppress weeds as a part of integrated weed management (IWM) system, are analysed and evaluated in this manuscript, in line with the results of longterm experiments. For sustainable maize (Zea mays L.) production, implementation of IWM system aiming to reduce reliance on chemical weed control within Europe is a key priority. This IWM system includes all possible solutions, such as preventive, direct, biological, mechanical and alternative measures. A cropping system approach
is essential to manage weeds, utilize genetic potential of maize genotypes and reduce yield losses due to weed competition. Long-term experiments are nowadays rare, but they are an excellent and reliable method for comparing cropping systems regarding yield and reduction of weed infestation level. In the research program implemented at the Maize Research Institute Zemun Polje in Central Serbia, the effects of different cropping measures and their interactions
as a part of IWMs were studied during ten years. Maize rotations with winter wheat (Triticum aestivum L.) and soybean (Glycine max (L.) Merr.), combined with herbicide application, showed the best effect on weed biomass reduction, 92.1% and 92.2%, respectively. Winter wheat was a better preceding crop for maize than soybean, especially in combination with herbicides applied in recommended as well as in half of recommended rate. Intensification of soil tillage significantly reduced maize weed infestation, especially abundance of perennial species: Johnson grass (Sorghum halepense (L.) Pers.), Canada thistle (Cirsium arvense (L.) Scop.) and field bindweed (Convolvulus arvensis L.). Other measures, such as type of fertilizer, maize row space and crop density, cover cropping and intercropping also affected weed biomass production in maize fields. Maize growing with reduced row spacing contributed to weed biomass reduction by 27.4%, while application of slow-release urea contributed to crop competitiveness. Weed biomass in sweet maize (Zea mays L. convar. saccharata) grown with common vetch as a cover crop was significantly reduced (48.5 g m-2) compared with the treatment without a cover crop
(564.3 g m-2).Straipsnyje analizuojama kukurūzų įvairių auginimo priemonių ir auginimo technologijų įtaka piktžolių mažėjimui ilgalaikio eksperimento metu. Europoje tvaraus kukurūzų auginimo svarbiausias prioritetas yra integruota piktžolių kontrolės (IPK) sistema, kuria siekiama sumažinti priklausomumą nuo cheminės piktžolių kontrolės. IPK sistema apima visus įmanomus sprendimus, pavyzdžiui, prevencines tiesiogines, biologines, mechanines ir alternatyvias priemones. Augalininkystės sistemų metodas yra labai svarbus siekiant kontroliuoti piktžoles, išnaudoti kukurūzų genotipų genetinį potencialą ir sumažinti derliaus nuostolius dėl piktžolių.
Šiais laikais ilgalaikiai eksperimentai vykdomi retai, tačiau jie yra puikus ir patikimas būdas augalininkystės sistemas palyginti pagal derlių ir pasėlių piktžolėtumo mažinimą. Centrinėje Serbijoje esančiame Kukurūzų tyrimų institute Zemun Polje įgyvendinant mokslinių tyrimų programą, kelerius metus kaip IPK dalis buvo tirta įvairių agrotechnikos priemonių įtaka ir jų sąveika. Siekiant sumažinti piktžolių biomasę efektyviausia buvo paprastųjų kukurūzų (Zea mays L.) sėjomaina su žieminiais kviečiais ir sojomis kartu su herbicidų panaudojimu – atitinkamai
92,1 ir 92,2 %. Žieminiai kviečiai buvo geresnis kukurūzų priešsėlis nei sojos, ypač kartu su herbicidais, panaudojus ir rekomenduojamą normą, ir pusę rekomenduojamos jų normos. Žemės dirbimas turėjo reikšmingos įtakos kukurūzų pasėlio piktžolėtumui, ypač daugiametėms piktžolėms: Sorghum halepense (L.) Pers., Cirsium arvense (L.) Scop. ir Convolvulus arvensis L. Kitos priemonės, pavyzdžiui, trąšų rūšis, kukurūzų tarpueilių plotis ir augalų tankumas, antsėlis bei įsėlis, taip pat turėjo įtakos piktžolių biomasei kukurūzų lauke. Kukurūzų auginimas mažesniu
tarpueilių pločiu piktžolių biomasę sumažino 27,4 %, o lėtai atpalaiduojamo karbamido panaudojimas padidino augalų konkurencinę gebą. Saldžiųjų kukurūzų (Zea mays L. convar. saccharata), augintų su vikių antsėliu, pasėlyje piktžolių biomasė reikšmingai sumažėjo
(48,5 g m-2), palyginus su variantu be antsėlio (564,3 g m-2)
Environmental Conditions Influence Induction of Key ABC-Transporter Genes Affecting Glyphosate Resistance Mechanism in Conyza canadensis
No full textConyza canadensis has been reported to be the most frequent weed species that evolved resistance to glyphosate in various parts of the world. The objective of the present study was to investigate the effect of environmental conditions (temperature and light) on the expression levels of the EPSPS gene and two major ABC-transporter genes (M10 and M11) on glyphosate susceptible (GS) and glyphosate resistant (GR) horseweed populations, collected from several regions across Greece. Real-time PCR was conducted to determine the expression level of the aforementioned genes when glyphosate was applied at normal (1×; 533 g·a.e.·ha−1) and high rates (4×, 8×), measured at an early one day after treatment (DAT) and a later stage (four DAT) of expression. Plants were exposed to light or dark conditions, at three temperature regimes (8, 25, 35 °C). GR plants were made sensitive when exposed to 8 °C with light; those sensitized plants behaved biochemically (shikimate accumulation) and molecularly (expression of EPSPS and ABC-genes) like the GS plants. Results from the current study show the direct link between the environmental conditions and the induction level of the above key genes that likely affect the efficiency of the proposed mechanism of glyphosate resistance
