On-farm investigations on integrated weed management in maize in three European countries

In 2011 and 2012, a total of 9 on-farm experiments were conducted to evaluate the effectiveness of different integrated weed management strategies (IWM) against the conventional approach (CON) in three important European maize producing countries. These sites were located in Italy, Germany and Slovenia and represent the range of various geographic, climatic and cultivation types in Europe. The IWM strategies tested were:Italy: the early-post emergence herbicide broadcast application when-if indicated by a predictive model of weed emergence after performing one scouting in the field, followed by hoeing,Germany: the early-post emergence band application combined with hoeing followed by a second hoeing andSlovenia: the harrowing at BBCH 12-13 of maize and low doses of post-emergence herbicide.Results showed that the different IWM strategies tested in the countries were similarly effective with the CON broadcast herbicide application in reducing weed density. In terms of mean weed density in the 3 countries and 2 years the efficacy of CON was significantly higher than IWM in only 2 out of 6 trials across two growing seasons. Furthermore, there were no significant differences of both management strategies in terms of grain yield. The study highlights the potential of IWM tools already available in Europe.Integriertes Unkrautmanagement in Mais auf Praxisbetrieben in drei europäischen LändernAn insgesamt 9 Standorten in 3 wichtigen europäischen Maisanbaugebieten wurden 2011 und 2012 auf Praxisbetrieben vergleichende Versuche mit Verfahren des integrierten Unkrautmanagements (IWM) und der konventionellen Unkrautbekämpfung (CON) durchgeführt. Die Versuchsstandorte lagen in Italien, Deutschland und Slowenien und repräsentieren unterschiedliche geographische, klimatische produktionstechnische Bedingungen in Europa. Folgende IWM-Strategien wurden getestet:Italien: Herbizid-Flächenbehandlung im frühen Nachauflauf nach Bonitur und standortspezifischem Entscheidungsmodell, gefolgt von Hackmaßnahme;Deutschland: Herbizid-Bandspritzung in Kombination mit Hackscharen und nachfolgende Hackmaßnahme undSlowenien: Striegeln im BBCH 12-13 und Flächenbehandlung mit reduzierten Herbizid-Aufwandmengen.Die Versuche zeigten, dass die verschiedenen IWM-Strategien in den Ländern die Unkrautdichte signifikant reduzieren konnte. Bezogen auf die mittlere Unkrautdichte in den 3 Ländern und 2 Jahren war die Wirksamkeit der konventionellen Behandlung (CON) nur in 2 von 6 Versuchen signifikant höher als die der integrierten Varianten (IWM). Die Kornerträge vom Mais unterschieden sich in keinem Fall signifikant voneinander. Die Untersuchungen verdeutlichen das Potenzial von IWM-Methoden, die bereits in Europa zur Verfügung stehen

La gestione integrata delle malerbe: un approccio sostenibile per il contenimento delle perdite di produzione e la salvaguardia dell'ambiente

The main issue that European agriculture is facing is related to maintaining and if possible increasing yields while reducing inputs - especially pesticides, including herbicides. Society is paying increasing attention to the quality of products as well as to the sustainability of the productive system. Control of weeds is necessary to achieve economically acceptable yields. The main tool is chemical weed control. This practice spread quickly after its introduction, due its efficacy and simplicity, but it also generated a series of agronomic and environmental issues. One of the solutions to maintain yields, while reducing herbicide use is the adoption of the Integrated Weed Management (IWM). IWM is based on the knowledge of weeds and their response to cropping practices, weed-crop competitive relationships and chemical and non-chemical means of control. IWM has had a quite remarkable success among researchers, politicians and public opinion, but has rarely been applied by farmers. The limited implementation of this management approach may have different explanations: i) IWM is more complex than conventional management as it requires greater skill and is more time consuming; ii) there is a lack of financial support and demonstration farms, necessary to convince the farmers to adopt it; iii) IWM is considered riskier than conventional management; iv) research has not succeeded in transferring scientific knowledge to the productive systems.The paper includes an analysis of several examples of IWM application in Italy in recent years (development of decision support systems, predictive models, formation of GIRE (Italian Herbicide Resistance Working Group) with the objective of defining their benefits and drawbacks and finding new solutions for the future. It is also underlined that the main difficulty in IWM development is the lack of integration between means of control and proactive agronomic practices that are suitable to prevent the spread and evolution of weeds in the fields

Target-site mutations and expression of als gene copies vary according to Echinochloa species

The sustainability of rice cropping systems is jeopardized by the large number and variety of populations of polyploid Echinochloa spp. resistant to ALS inhibitors. Better knowledge of the Echinochloa species present in Italian rice fields and the study of ALS genes involved in target- site resistance could significantly contribute to a better understanding of resistance evolution and management. Using a CAPS-rbcL molecular marker, two species, E. crus-galli (L.) P. Beauv. and E. oryzicola (Vasinger) Vasing., were identified as the most common species in rice in Italy. Mutations involved in ALS inhibitor resistance in the different species were identified and associated with the ALS homoeologs. The relative expression of the ALS gene copies was evaluated. Molecular characterization led to the identification of three ALS genes in E. crus-galli and two in E. oryzicola. The two species also carried different point mutations conferring resistance: Ala122Asn in E. crus-galli and Trp574Leu in E. oryzicola. Mutations were carried in the same gene copy (ALS1), which was significantly more expressed than the other copies (ALS2 and ALS3) in both species. These results explain the high resistance level of these populations and why mutations in the other ALS copies are not involved in herbicide resistance

Non-Functional Jaw Muscular Activity in Patients with Disorders of Consciousness Revealed by A Long-Lasting Polygraphy

The presence of involuntary, non-functional jaw muscle activity (NFJMA) has not yet been assessed in patients with disorders of consciousness (DOC), although the presence of bruxism and other forms of movement disorders involving facial muscles is probably more frequent than believed. In this work, we evaluated twenty-two prolonged or chronic DOC patients with a long-lasting polygraphic recording to verify NFJMA occurrence and assess its neurophysiological patterns in this group of patients. A total of 5 out of 22 patients showed the presence of significant NFJMA with electromyographic patterns similar to what can be observed in non-DOC patients with bruxism, thus suggesting a disinhibition of masticatory motor nuclei from the cortical control. On the other hand, in two DOC patients, electromyographic patterns advised for the presence of myorhythmia, thus suggesting a brainstem/diencephalic involvement. Functional, non-invasive tools such as long-lasting polygraphic recordings should be extended to a larger sample of patients, since they are increasingly important in revealing disorders potentially severe and impacting the quality of life of DOC patients

Occurrence of Resistance to ALS Inhibitors in European Cyperus esculentus L.: Characterisation and Implications for Management

Yellow nutsedge (C. esculentus) is a perennial geophyte and invasive weed which is very difficult to control in rice and other irrigated row crops. Acetolactate synthase (ALS) inhibitors are the most commonly used herbicides to control sedges in rice. Failure to control C. esculentus was recently reported in a rice field in north-western Italy. The resistance status of this C. esculentus population was determined through a whole-plant bioassay. The mechanism underlying the resistance was elucidated, and the available chemical and non-chemical control options were discussed. The population proved to be resistant to halosulfuron and azimsulfuron at the recommended field rate. The ALS trancripts amplified from resistant and susceptible plants revealed the presence of a Pro197-to-Arg amino acid substitution in resistant plants, indicating that the resistance mechanism is target-site mediated. This is the first confirmation of herbicide resistance in C. esculentus in Europe. Resistance management should be based on an integrated approach, through the combination of diversified cultural and agronomic practices that can limit its spread and propagation through tubers

A New Ala-122-Asn Amino Acid Change Confers Decreased Fitness to ALS-Resistant Echinochloa crus-galli

Gene mutations conferring herbicide resistance may cause pleiotropic effects on plant fitness. Knowledge of these effects is important for managing the evolution of herbicide-resistant weeds. An Echinochloa crus-galli population resistant to acetolactate synthase (ALS) herbicides was collected in a maize field in north-eastern Italy and the cross-resistance pattern, resistance mechanism and fitness costs associated to mutant-resistant plants under field conditions in the presence or absence of intra-specific competition were determined. The study reports for the first time the Ala-122-Asn amino-acid change in the ALS gene that confers high levels of cross-resistance to all ALS inhibitors tested. Results of 3-year growth analysis showed that mutant resistant E. crus-galli plants had a delayed development in comparison with susceptible plants and this was registered in both competitive (3, 7, and 20 plants m-2) and non-competitive (spaced plants) situations. The number of panicles produced by resistant plants was also lower (about 40% fewer panicles) than susceptible plants under no-intraspecific competition. Instead, with the increasing competition level, the difference in panicle production at harvest time decreased until it became negligible at 20 plants m-2. Evaluation of total dry biomass as well as biomass allocation in vegetative parts did not highlight any difference between resistant and susceptible plants. Instead, panicle dry weight was higher in susceptible plants indicating that they allocated more biomass than resistant ones to the reproductive organs, especially in no-competition and in competition situations at lower plant densities. The different fitness between resistant and susceptible phenotypes suggests that keeping the infestation density as low as possible can increase the reproduction success of the susceptible phenotype and therefore contribute to lowering the ratio between resistant and susceptible alleles. If adequately embedded in a medium or long-term integrated weed management strategy, the presence of R plants with a fitness penalty provides an opportunity to minimize or reverse herbicide resistance evolution through the implementation of integrated weed management, i.e., all possible control tools available