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The persistence of perennial herbaceous species is threatened by increasing aridity. However, summer dormancy is a strategy conferring superior survival to grasses adapted to hot and dry summers. The role of temperature on the induction of summer dormancy was investigated in the perennial grass Dactylis glomerata to analyse the potential expression of this strategy under warmer climates.We tested seven populations of D. glomerata originating from Morocco to Norway across the same latitudinal gradient in a five‐site experiment. One population of the highly summer‐dormant grass Poa bulbosa was used as a reference. Plants were grown from autumn in pots under full irrigation for 1 year mostly under open‐air shelters. Heading date (ear emergence preceding flowering) was recorded and foliage senescence was assessed from end of spring until autumn. The maximum plant senescence under summer irrigation indicated the level of dormancy expression. Summer dormancy onset, release, expression and duration were modelled as a function of climatic variables.From north to south, the duration of summer dormancy of the Mediterranean populations of D. glomerata and P. bulbosa ranged from 0 to 122 days, and 79 to 200 days, respectively. P. bulbosa was always completely dormant, while dormancy expression of D. glomerata was positively correlated with the sum of temperatures from winter onset (R2 = 0.57) and with the mean of minimum temperatures in summer (R2 = 0.73). Dormancy onset, release and duration were also positively correlated with thermal time from winter onset, while the duration of summer dormancy was longer as maximum temperatures increased. Mapping the European regions with climates allowing the expression of summer dormancy in D. glomerata showed that the potentially inductive areas for this strategy may expand in parallel with increasing summer aridity under a future climate warming scenario.Synthesis. The large phenotypic variability of the expression of summer dormancy in D. glomerata was driven by temperature, suggesting that this strategy may have a greater role in higher latitudes to increase plant survival over the predicted hotter and drier summers. Leveraging this strategy for the choice and selection of suitable populations could enhance future adaptation of major perennial grasses to climate change. [ABSTRACT FROM AUTHOR]

RATIONALE: No study has investigated the variations in stable isotope ratios (SIRs) of bioelements within a Protected Designations of Origin (PDO) cheese and few studies have focused on the dietary background of animals. For traceability purposes, it is important to know how and whether these issues affect SIRs in a PDO cheese. METHODS: Thirty-six Pecorino Siciliano cheese samples were collected in three east-Sicilian areas in seasons in which green herbage was present or absent in the diet of the animals. The determination of C, N and S SIRs was performed using an isotope ratio mass spectrometer coupled with an elemental analyser. The H and O SIRs were measured using an isotope ratio mass spectrometer equipped with a thermal conversion elemental analyser pyrolysis unit. RESULTS: The C, N, H, O and S SIRs measured in defatted cheeses were subjected to a multivariate stepwise discriminant analysis to verify if cheeses could be distinguished based on their geographical origin and on the animals' feeding regimen. Sulfur and nitrogen SIRs allowed the best discrimination among the three areas (97.2% correct classification of the cheeses). The discrimination of the feeding system, to check the presence or not of fresh forage in the diet of the animals, correctly classified 86.1% of the cheeses. The C and O SIRs were the most effective parameters. CONCLUSIONS: This study demonstrates that the variability in C, H, O, N and S SIRs can allow discrimination between cheeses produced in a narrow geographical region within a PDO area. This may lead to the search for new tools in authentication studies such as the creation of specific isoscapes. Moreover, this study confirms that SIR determination can also discriminate cheeses obtained from animals fed in stalls from those produced when animals have access to green forage, with benefit in terms of environmental impact, animal welfare and product quality. [ABSTRACT FROM AUTHOR]

Soils of the Mediterranean area are subjected to erosion due to the cropping systems and crop managements adopted. This causes a loss of crop productivity that could be initially replaced with an increase of fertilizers, but in the end leads to land abandonment. The areas subjected to soil erosion in the Mediterranean area cover 1,309,000 km, equal to 15 % of the land of Mediterranean countries. In dry farming condition, the farmer's choices are often constrained by the prevailing climatic conditions. Rainfall amount and distribution represent the main constraints that lead farmers to choose annual autumn-winter crops. In this environment, the growing cycle of autumn-winter crops, such as durum wheat, determines a lack of soil covering during the first rains that occur in early autumn and winter. Soil losses by erosion also determine nutrient losses and affect soil organic matter content. All these aspects are evaluated by ongoing research started in 1996 in an area of the internal hills of Sicily (Italy) in the center of the Mediterranean basin. In this experimental site, on a 27 % slope, the effect of different cropping systems to determine surface runoff and soil losses was evaluated. In each plot, (40 × 8) m, a series of devices were installed in order to determine the amount of runoff and sediment: four covered trap channels were installed at the bottom of each plot, each channel drained into pipes which emptied into a tank to collect surface runoff and soil losses. After each erosive rainfall, the amount of water, of sediments, and the nitrate-nitrogen were measured. Soil organic matter was determined every fall at 0-30 and 31-60 cm depth. The highest annual values of soil losses were observed in the annual tilled crops, such as the typical Mediterranean crop rotation 'durum wheat-durum wheat-fallow' (11.2 t ha year). Very low soil losses were observed in the plots managed with perennial crops, alfalfa (0.34 t ha year), Italian ryegrass in pure stand and in mixtures with subterranean clover (3.2 t ha year), and subterranean clover (1.7 t ha year). The perennial giant miscanthus and moon trefoil reduced soil losses to 0.1 t ha year. The benefit of the cultivation of perennial crops instead of tilled crops was also highlighted in relation to organic matter content. The rotation 'giant miscanthus (from 1997 to 2001)-moon trefoil (from 2002 to 2015)' made it possible to increase soil organic matter from 1.03 to 2.51 % in the average of the first 60 cm soil depth. [ABSTRACT FROM AUTHOR]

A general obstacle to the development of perennial grasses is the relatively high cost of propagation and planting. The objective of the present study was to investigate new propagation and planting methods of giant reed ( Arundo donax L.), miscanthus ( Miscanthus x giganteus Greef et Deuter) and switchgrass ( Panicum virgatum L.). Field and open-air pot trials were carried out in four different locations across Europe: hydro-seeding of switchgrass was tested in field trials at the experimental farm of the University of Bologna, Italy; stem propagation and bud activation methods of miscanthus were evaluated in field experiments in Péteri, Hungary; giant reed rhizome and stem propagations were compared in a field trial in Aliartos, Greece; finally, an open-air pot trial was carried out in Catania, Italy, using single-node stem cuttings of giant reed. Hydro-seeding emerged as a feasible and promising technique for switchgrass to ensure prompt seed emergence and weed control during plant establishment. Direct stem plantings of miscanthus were successful, and activated stem-buds were able to sprout in field conditions; however, timely stem transplant was determinant for shoot density and biomass yield. In giant reed, rhizome propagation showed a higher stem density and biomass yield than stem propagation; however, the yield gap was not significant from the second year onwards. Single-node rooting was mainly driven by air temperature. Nodes from basal stems showed higher rooting rates than median and apical ones. Growth regulator pretreatments enhanced rooting rate only at transplanting times under suboptimal air temperatures. In general, these experiments provided insights into propagation strategies aimed at enhancing the establishment phase of perennial grasses. [ABSTRACT FROM AUTHOR]

Great effort has been placed to identify the most suited bioenergy crop under different environments and management practices, however, there is still need to find new genetic resources for constrained areas. For instance, South Mediterranean area is strongly affected by prolonged drought, high vapour pressure deficit (VPD) and extremely high temperatures during summertime. In the present work we investigated the soil water effect on crop growth and leaf gas exchange of Saccharum spontaneum L. ssp. aegyptiacum (Willd.) Hackel, a perennial, rhizomatous, herbaceous grass. Furthermore, the net increase of biomass production per unit light intercepted [radiation use efficiency (RUE)] and per unit water transpired [water use efficiency (WUE)] was also studied. To this end a field trial was carried out imposing three levels of soil water availability (I100, I50 and I0, corresponding to 100%, 50% and 0% of ETm restutition) under a semi-arid Mediterranean environment. Leaf area index (LAI), stem height, biomass dry matter yield, CO2 assimilation rate, and transpiration rate resulted significantly affected by measurement time and irrigation treatment, with the highest values in I100 and the lowest in I0. RUE was the highest in I100 followed by I50 and I0; on the other hand, WUE was higher in I0 than I50 and I100. At LAI values greater than 2.0, 85% photosynthetically active radiation was intercepted by the Saccharum stand, irrespective of the irrigation treatment. Saccharum spontaneum spp. aegyptiacum is a potential species for biomass production in environment characterized by drought stress, high temperatures and high VPD, as those of Southern Europe and similar semi-arid areas. [ABSTRACT FROM AUTHOR]

In the Iblei plateau (Sicily, Southern Italy) the native dairy cattle breed Modicana during the spring season grazes exclusively on natural pastures for the production of the Ragusano protected denomination of origin cheese. Along the grazing season, herbage undergoes to changes on protein, fibre and moisture content, affecting quality parameters such as plant carotenoids concentration, involved in the colour and nutritional characteristics of dairy products and potential biomarkers for authenticating fed green pasture-based diets. The aim of this work was to assess whether the cheese traceability index, based on the carotenoids spectra data elaboration, could be related to seasonal variations of floral composition and pasture quality. Four herbage and cheese samples were collected every two weeks in two representative farms of this area, from March to May 2013. Pasture characteristics as pastoral vegetation composition and pastoral value were analysed using the methodology developed for pastoral resources studies. Traceability index showed a significant positive correlation with pasture moisture and crude protein content (r=0.729* and 0.853**, respectively), while it was negatively correlated with fibre content (r=-0.719*). [ABSTRACT FROM AUTHOR]