scholarly journals Long-Term Productivity of Thirteen Lowland and Upland Switchgrass Ecotypes in the Mediterranean Region

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 923
Author(s):  
Efthymia Alexopoulou ◽  
Federica Zanetti ◽  
Eleni G. Papazoglou ◽  
Konstantinos Iordanoglou ◽  
Andrea Monti
Keyword(s):  
Panicum Virgatum ◽  
Mediterranean Climate ◽  
Biomass Crop ◽  
The North ◽  
Panicum Virgatum L ◽  
The Usa ◽  
Biomass Yields ◽  
The Mediterranean ◽  
Marginal Soil

Switchgrass (Panicum virgatum L.) has been identified in the USA as an ideal biomass crop, in relation to its wide environmental suitability, mainly linked to the availability of both upland and lowland ecotypes, allowing the possibility of growing this species in most of the North American region. Switchgrass is conventionally grown for forage, but more recently, it has been considered as a model biofuel crop. Early European studies on switchgrass as a bioenergy crop started in the late 1990s, when a multi-location field trial was established in Greece (Aliartos) and Italy (Ozzano) to compare the productivity of 13 switchgrass genotypes, including upland (Carthage, Blackwell, Caddo, CIR, Forestburg, SU 94-1, Summer) and lowland (Alamo, Kanlow, Pangburn, SL 93-2, SL 93-3, SL94-1) genotypes. The scope was to identify the most suitable ecotype within each environment and, possibly, the best performing variety. The trials lasted 17 years (1998–2014) in Greece and 13 years (1998–2010) in Italy. While in Italy the trial was rainfed and unfertilized, in Greece, where the soil was marginal, drip irrigation was always applied, and the plots were fertilized regularly. The biomass yields in Greece, as averages across the 17 years, were similar for the lowland and upland varieties (11.5 vs. 11.1 Mg ha−1, respectively), while in Italy, as averages across the 13 years, the differences were relevant: 15.4 vs. 11.3 Mg ha−1 for lowland and upland, respectively. Alamo (lowland) was the most productive variety, both in Greece and Italy, with average annual yields of 12.7 and 16.6 Mg ha−1, respectively; CIR in Greece (10.1 Mg ha−1) and Forestburg in Italy (9.1 Mg ha−1) (both upland) were the least productive genotypes. The present results demonstrate the good suitability of switchgrass as biomass crop for the Mediterranean climate. Despite the very marginal soil (i.e., very shallow and with a sandy texture) in the Greek trial, the application of regular fertilization and irrigation produced biomass yields above 11 Mg ha−1 (grand mean) in the present 17-year-long study.

Coastal climatology of the North-Western Mediterranean area for long-term and short-term risk assessment.

2020 ◽  
Author(s):  
Carlo Brandini ◽  
Stefano Taddei ◽  
Valentina Vannucchi ◽  
Michele Bendoni ◽  
Bartolomeo Doronzo ◽  
...  
Keyword(s):  
Risk Assessment ◽  
High Resolution ◽  
Mediterranean Area ◽  
Western Mediterranean ◽  
Climate Trends ◽  
Short Term ◽  
The North ◽  
The Mediterranean ◽  
North Western

<p>In this work we present the results obtained through a dynamic downscaling of the ERA5 reanalysis dataset (hindcast) of ECMWF, using high-resolution meteorological and wave models defined on unstructured computation grids along the Mediterranean coasts, with a particular focus on the North-Western Mediterranean area. Downscaling of the ERA5 meteorological data is obtained through the BOLAM and MOLOCH models (up to a resolution of 2.5 km) which force an unstructured WW3 model with a resolution of up to 500 m along the coast. Models were validated through available meteorological stations, wave buoy data and X-band wave radars, the latter for the purposes of wave spectra validation.</p><p>On the one hand, this allowed, by extracting the time series of some attack parameters of the waves along the coast, and according to the type of coast (rocky coasts, sandy coasts, coastal structures etc.), to compute the return periods and to characterize the impact of any individual storm. On the other hand, it is possible to highlight some trends observed in the last 30 years, during which recent research is showing an increasing evidence  of some changes in global circulation at regional to local scales. These changes also include effects of wind rotation, wave regimes, storm surges, wave-induced coastal currents and coastal morphodynamics. For example, in the North-Western Mediterranean extreme events belonging to cyclonic weather-types circulation with stronger S-SE components (like the storm of October 28-30th 2018 and many others), rather than events associated with perturbations of Atlantic origin and zonal circulation, are becoming more frequent. These long-term wind/wave climate trends can have consequences not only in the assessment of long-term risk due to main morphodynamic variations (ie. coastal erosion), but also in the short-term risk assessment.</p><p>This work was funded by the EU MAREGOT project (2017-2020) and ECMWF Special Project spitbran  “Evaluation of coastal climate trends in the Mediterranean area by means of high-resolution and multi-model downscaling of ERA5 reanalysis” (2018-2020).</p>

scholarly journals Outbreak of Smut Caused by Tilletia maclaganii on Cultivated Switchgrass in Iowa

Plant Disease ◽  
2000 ◽  
Vol 84 (5) ◽  
pp. 596-596 ◽  
Author(s):  
C. E. Gravert ◽  
L. H. Tiffany ◽  
G. P. Munkvold
Keyword(s):  
Biomass Production ◽  
Panicum Virgatum ◽  
Fungal Spores ◽  
Sampling Procedure ◽  
Smut Fungi ◽  
Iowa State College ◽  
State College ◽  
The North ◽  
Panicum Virgatum L ◽  
Seed Yields

Switchgrass (Panicum virgatum L.), a prairie grass native to Iowa, is cultivated for forage and biomass production. During the late 1990s, biomass and seed yields of switchgrass grown in southern Iowa began to decline, and the reduction has been attributed to unidentified diseases. In 1999, many plants in previously low-yielding fields were stunted and flowered prematurely. Glumes had an uncharacteristic purple pigmentation, and seeds had been replaced by fungal spores. A smut fungus identified as Tilletia maclaganii (Berk.) G.P. Clinton (1) was associated consistently with fields that yielded poorly. Teliospores were red-orange when immature and turned dark brown as they matured. Teliospores were globose to slightly irregular, ≈18 to 25 µm in diameter, finely verrucose, with a thick exospore. True sterile cells also were present. T. maclaganii infects switchgrass and has been reported previously in Iowa (2), although it is found only occasionally on the state's native switchgrass. The prevalence and incidence of disease was surveyed in late August 1999. A weighted random sampling procedure was used to select switchgrass production fields from 60 fields involved in the Chariton Valley Biomass Project. Fields were located in Appanoose, Lucas, Monroe, and Wayne counties in southern Iowa. The sampling procedure was designed so the probability of each field being chosen was proportional to its area. This resulted in samples being taken from 17 fields representing ≈50% of the total area of the 60 fields. All sampled fields were planted with the predominant cultivar, Cave-in-Rock. In each field, five 1-m2 samples (≈60 to 250 tillers) were taken from arbitrary points. The incidence of smut (percentage of tillers with smut) was calculated for each sample. Smut was found in 15 of 17 fields. We estimated that 50 to 82% of the area in switchgrass production in these counties was infested with T. maclaganii. The mean incidence of smut was estimated at 10.1% of all tillers in the area. Incidence in individual fields ranged from 0 to 70%. Fields with incidence >50% yielded less than half of the expected biomass. Some infested seed-production fields were a total loss in 1999. This disease presents a serious threat to the cultivation of switchgrass for biomass production in southern Iowa. The disease cycle for T. maclaganii is poorly documented, but because switchgrass is a perennial species, it is likely that affected fields will have recurring epidemics. Susceptibility of other cultivars is unknown but needs to be investigated. References: (1) G. W. Fischer. 1953. Manual of the North American Smut Fungi. Ronald Press, NY. (2) J. C. Gilman and W. A. Archer. The fungi of Iowa parasitic on plants. Iowa State College J. Sci. 3:299, 1929.

scholarly journals The Strong Precipitation of the Dry Warm Front Cyclone in Syria and Its Prediction by Data Mining Modeling

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1667
Author(s):  
Jianhong Wang ◽  
Nour Alakol ◽  
Xing Wang ◽  
Dongpo He ◽  
Kanike Raghavendra Kumar ◽  
...  
Keyword(s):  
Mediterranean Climate ◽  
Forecast Accuracy ◽  
Middle Layer ◽  
Forecast Model ◽  
Winter Precipitation ◽  
Reanalysis Data ◽  
The North ◽  
Warm Front ◽  
The Mediterranean ◽  
Upper Level

The Eastern inland of Syria has a Mediterranean climate in the north and a tropical desert climate in the south, which results in a dry south and wet north climate feature, especially in winter. The circulation dynamics analysis of 16 winter strong precipitation events shows that the key system is the dry and warm front cyclone. In most cases (81–100% of the 16 cases), the moisture content in the northern part of the cyclone is higher than that in the southern part (influenced by the Mediterranean climate zone). The humidity in the middle layer is higher than that near the surface (uplifting of the dry warm front), and the thickness of the wet layer and the vertical ascending layer obviously expands upward (as shown by the satellite cloud top reflection). These characteristics lead to the moisture thermodynamic instability in the eastern part of the cyclone (dry and warm air at low level and wet and cold air at upper level). The cyclone flow transports momentum to the local humid layer of the Mediterranean climate belt and then causes unstable conditions and strong rainfall. Considering the limitations of the Syrian ground station network, the NCEP/CFSR global reanalysis data and MODIS aqua-3 cloud parameter data are used to build a multi-source factor index of winter precipitation from 2002 to 2016. A decision tree prediction model is then established and the factors index is constructed into tree shapes by the nodes and branches through calculating rules of information entropy. The suitable tree shape models are adjusted and selected by an automated training and testing process. The forecast model can classify rainfall with a forecast accuracy of more than 90% for strong rainfall over 30 mm.

scholarly journals Window Design of Naturally Ventilated Offices in the Mediterranean Climate in Terms of CO2 and Thermal Comfort Performance

2020 ◽  
Vol 12 (2) ◽  
pp. 473 ◽  
Author(s):  
Hardi K. Abdullah ◽  
Halil Z. Alibaba
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Mediterranean Climate ◽  
Computational Modelling ◽  
Co2 Concentration ◽  
The North ◽  
Adaptive Thermal Comfort ◽  
Adaptive Comfort ◽  
The Mediterranean ◽  
Window Design

Natural ventilation through window openings is an inexpensive and effective solution to bring fresh air into internal spaces and improve indoor environmental conditions. This study attempts to address the “indoor air quality–thermal comfort” dilemma of naturally ventilated office buildings in the Mediterranean climate through the effective use of early window design. An experimental method of computational modelling and simulation was applied. The assessments of indoor carbon dioxide (CO2) concentration and adaptive thermal comfort were performed using the British/European standard BS EN 15251:2007. The results indicate that when windows were opened, the first-floor zones were subjected to the highest CO2 levels, especially the north-facing window in the winter and the south-facing window in the summer. For a fully glazed wall, a 10% window opening could provide all the office hours inside category I of CO2 concentration. Such an achievement requires full and quarter window openings in the cases of 10% and 25% window-to-floor ratios (WFR), respectively. The findings of the European adaptive comfort showed that less than 50% of office hours appeared in category III with cross-ventilation. The concluding remarks and recommendations are presented.

scholarly journals Impact of Growing Environment on Anthracnose Severity of Switchgrass Cultivars and Clones

Plant Disease ◽  
2016 ◽  
Vol 100 (10) ◽  
pp. 2034-2042
Author(s):  
Lindsey Hoffman ◽  
Laura M. Chaves ◽  
Eric N. Weibel ◽  
Hilary S. Mayton ◽  
Stacy A. Bonos
Keyword(s):  
Panicum Virgatum ◽  
Biomass Yield ◽  
Limited Information ◽  
Panicum Virgatum L ◽  
Growing Environment ◽  
Selection For ◽  
The Impact ◽  
Clonal Repeatability ◽  
Plant Basis ◽  
Marginal Soil

Anthracnose (caused by Colletotrichum navitas) has the potential to significantly reduce biomass yield of switchgrass (Panicum virgatum L.); however, limited information is available on the impact of growing environment on tolerance of switchgrass to anthracnose. Therefore, the major objectives of this study were to (i) examine genotype–environment (G × E) effects on anthracnose severity in populations of switchgrass cultivars and individual genotypes and (ii) determine clonal repeatability estimates and stability analysis of anthracnose tolerance on individual switchgrass genotypes. Two experiments were conducted at one prime and two marginal soil locations in New Jersey. In all, 14 switchgrass cultivars were established from seed in 2008 for experiment 1 and 50 replicated switchgrass clones were planted in 2009 for experiment 2 at all three locations. Anthracnose was rated visually in 2010 for experiment 1 and in 2010 and 2011 for experiment 2. Significant G × E interactions were detected for both experiments (P ≤ 0.05) and anthracnose severity varied by location and cultivar. Clonal repeatability estimates for disease tolerance among clones was 0.78 on a clonal basis and 0.32 on a single-plant basis. Lowland ecotypes exhibited less disease overall than upland ecotypes. Results from this study indicate that selection for improved tolerance to anthracnose should be conducted after evaluation across several environments over multiple years.

scholarly journals Switchgrass (Panicum virgatum L.) Cultivar Adaptation, Biomass Production, and Cellulose Concentration as Affected by Latitude of Origin

ISRN Agronomy ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Paul G. Jefferson ◽  
W. Paul McCaughey
Keyword(s):  
Biomass Production ◽  
Panicum Virgatum ◽  
Nutritive Value ◽  
Stand Density ◽  
Canadian Prairie ◽  
Grazing Cattle ◽  
Northern Latitudes ◽  
Panicum Virgatum L ◽  
The Usa ◽  
Cellulose Concentration

Ten cultivars of switchgrass (Panicum virgatum L.) of northern and southern origins that had demonstrated adaptation to North Dakota were evaluated for biomass production, cellulose concentration, and nutritive value in the southern Canadian prairie region: Saskatchewan and Manitoba. In this region, cultivars adapted to northern latitudes present interest for biomass production. Latitude of origin of the cultivars was positively correlated to stand density (r=0.83, P<0.01), biomass production (r=0.69, P<0.01), and cellulose (r=0.84, P<0.01), and negatively correlated with organic matter digestibility (r=−0.86, P<0.01) and N (r=−0.85, P<0.01). Dacotah and ND 3743, the northern origin cultivars, were more persistent in Brandon, MB (94 to 100% stand density) and exhibited higher cellulose and hemicellulose concentrations than southern cultivars. Southern cultivars produced higher biomass than northern-origin cultivars until they suffered significant stand and biomass decline. Cave-in-Rock, the southern origin cultivar, did not persist in the third year after seeding. However, southern-adapted cultivars exhibited better nutritive value for grazing cattle. We conclude that switchgrass production in the southern Canadian prairie should utilize the USA cultivars from northern latitudes or adapted Canadian cultivars should be developed.

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