Weed sustainable managment in agricultral and non-agricultural areas

Sustainable agriculture is a way to assure the availability of natural resources for future generations.Weed management in cultivated and not cultivated areas is part of sustainable agriculture as well, and has to face three important challenges: economical (to increase income and competitiveness of farm sector), social (give rural areas opportunity of economic development and improvement of living conditions), environmental (promote good agricultural practices and preserve habitats, biodiversity and landscape). The first two challenges involve the in-depth study of models, the economic threshold of intervention, the management of herbicide resistance phenomena, the study and development of new herbicide molecules, or even modern formulations, leading to the optimization of treatments with possible reduction of distributed doses per hectare. Environmental issues must be set in the studies to assess and manage the factors leading to phenomena of diffuse or point pollution (i.e. water volumes, soil, etc.). However, a sustainable agriculture production must take into account consumers’ needs and concerns, especially about food health and safety with respect to production methods (traditional, integrated and biological). In this context, the results obtained by the development of more advanced active principles, the spread of public and private Integrated Production Specifications (Disciplinari di Produzione Integrata) and the greater and greater commitment by the institutions in charge of monitoring the agro-pharmaceutical residues in agro-food products, can be set. The SIRFI SIRFI (Società Italiana per la Ricerca sulla Flora Infestante), thanks to the multi-disciplinarity of the structures supporting it, always takes an active part into innovation especially aimed to the identification of tools implementing farm activity sustainability

Efficacy of Fungicides against Fusarium Head Blight Depends on the Timing Relative to Infection Rather than on Wheat Growth Stage

Fungicides used to control Fusarium head blight (FHB) are commonly applied at the wheat growth stage considered to be most susceptible, i.e., anthesis. We compared the efficacy of the most commonly used fungicide groups that were applied following two strategies: (i) at pre-defined growth stages, from the first half of heading to the end of flowering (experiment 1, in 2013 to 2015), or (ii) based on timing of infection by F. graminearum, specifically at 10, 7, 4, or 1 day before, or 3 or 5 days after artificial inoculation of the fungus (experiment 2, in 2017 and 2018). Fungicide efficacy was evaluated in terms of FHB incidence, FHB severity, and DON contamination by using generalised mixed models. In experiment 1, all fungicide groups reduced FHB severity and DON but only by <50% compared to an untreated control, with no differences among fungicides or growth stages at time of application. In experiment 2, the efficacy of fungicides was higher for applications at 1 or 4 days before inoculation than at 7 or 10 days before or 3 or 5 days after inoculation, with differences among fungicide groups. Based on our results, the timing of fungicide application for FHB control should be based on the time of F. graminearum infection rather than on wheat phenology

Relay intercropping can efficiently support weed management in cereal-based cropping systems when appropriate legume species are chosen

Relay intercropping of subsidiary legumes with durum wheat (living mulch) can be a viable option to support ecological weed control and optimize nutrient cycling in cereal-based cropping systems. However, the lack of knowledge on suitable legume species is often identified as the main bottleneck for the successful application of legume living mulches. This study aimed to evaluate the suitability of 12 different legumes for relay intercropping with wheat in two contrastingMediterranean cereal-based cropping systems respectively characterized by low-input and integrated management. Each legume was monitored from the undersowing in wheat until the following spring and we compared direct drilling to broadcast sowing of legumes. None of the undersown legumes showed a negative effect on the wheat grain yield. Relay intercropping of legumes proved to be an effective solution to control weeds before and after the wheat harvest, provided suitable legumes species are chosen. Suitable legumes reduced the weed biomass up to the 90% during the intercropping and up to 94% in the following spring. On the contrary, legumes such as T rif oliumresupinatum, V icia villosa,Medicago truncatula, and Medicago scutellata boosted weed growth in the following spring in comparison with the control. According to the performance of legumes, Medicago sativa, T rifolium repens and Medicago lupulina had the most suitable characteristics for relay intercropping with durum wheat at the Ravenna site, in a highly productive region whereas Medicago sativa, Hedysarum coronarium and T rif olium subterraneum performed better in the low-input system near Pisa, where yields are generally lower. This is the first time that such a diversity in legumes species is tested in the same experiment for relay intercropping under diversified environmental and management conditions. The results of this study can support farmers in selecting the most appropriated legume species for their specific cropping systems and local conditions

Sensibilit\ue0 verso fungicidi IBS in popolazioni di Cercospora beticola raccolte in Val Padana

In the period 1998-2001, a study was carried out in several sugar beet fields of northern Italy to determine the distribution of sensitivity to SBIs fungicides within populations of Cercospora beticola from the Po Valley. The study showed a decrease in the sensitivity level of some fungal strains grown on fungicide amended medium. In spite of the high number of tested fungal strains (1550), it was not possible to draw final conclusions about the real magnitude of this phenomenon; however, the progress of the situation has to be studied further and, in the meantime, the anti-resistance strategies must not be neglected

Le malattie del grano nell'Italia settentrionale

Le coltivazioni di grano del nord dell’Italia sono soggette ad attacchi di vari funghi patogeni; la diffusione e l’incidenza di queste malattie varia però da un areale all’altro, di stagione in stagione - in rapporto all’andamento meteorologico stagionale – e da coltura a coltura – in relazione alle scelte colturali e alla gestione agronomica. In questo contributo si è voluto delineare l’evoluzione delle principali malattie (oidio, ruggine bruna, septoriosi e fusariosi della spiga) dal 2006 al 2013

Influenza di strategie anti-resistenza sulla sensibilit\ue0 ai fungicidi in Cercospora beticola

In the years 2003 and 2004, the effect of different SBI and QoI fungicides, used alone, in mixture or in alternation, on the sensibility level of Cercospora beticola populations was studied. Sensibility was studied in laboratory using fungal isoltes collected in the experimental fields before the beginning of fungicide sprays and after three fungicide applications. A decrease of fungal populations\u2019 sensibility was registered for tetraconazole, when it was used alone or in mixture with azoxystrobin at reduced rates. On the contrary, the use of tetraconazole and azoxystrobin at full rates, as well as the use of difenoconazole and fenpropidin, significantly reduced the proportion of isolates showing reduced sensibility to tetraconazole. No reduced sensibility was observed for azoxystrobin. Some isolates were less sensitive to difenoconazole in one experimental site that had been shown reduced sensibility to IBS fungicides

Concentration dynamics of SBI and QoI fungicides in sugar beet leaves

A three-year trial was carried out in order to study the long-term dynamics of foliar concentration of two fungicides belonging to the SBI (Sterol Biosysnthesis Inhibitor) and QoI (Quinone outside Inhibitor) groups, the most important active substances used in controlling Cercospora leaf spot. Fungicides were applied following the usual schedule, with three sprays per season at 20-day intervals. Foliar concentrations of both fungicides were tested after 1, 3, 9 and 18 days after application. Results showed that the foliar concentration of these substances changes according to fungicide characteristics, application time, time elapsed after distribution, and size of sugar beet canopy. These results suggest new approaches for applying fungicides to control Cercospora leaf spot epidemics

Dynamics of fungi and related mycotoxins during cereal storage in silo bags

The aim of this work was to investigate the dynamics of fungi and related mycotoxins during cereal storage in silo bags. A 2-year trial was organised (2009-2011); in each year, two silo bags, filled with maize and durum wheat respectively, were prepared . During storage, meteorological data were collected from a close station and temperature, CO2 and O2 were measured inside the silos. Grain was sampled from silo filling (September) every 40 days until June (7/8 samples per silo per year). Water activity of grain, colony forming units (CFU) and mycotoxin content (fumonisins, aflatoxins and ochratoxin in maize, deoxynivalenol and ochratoxin in wheat) were determined. Temperature inside the silo bags followed the trend of external temperature, with a more limited variation. A decrease of O2 was observed from 16.4% to 2.0% in maize and from 15.7% to 15.1% in wheat; the decrease was balanced by CO2 increase. Minor variations were registered in grain water activity and CFU and mycotoxin content did not change significant throughout the storage period; the results were consistent in the two years. On the basis of these results, silo bags prove to be suitable for safe cereal storage