• Energy Research

Castor bean (Ricinus communis L.), is a plant belonging to the Euphorbiaceae family and one of the most interesting oil seed crops to develop and study in the Mediterranean basin. The main trait that enhances castor cultivation is its oil content, which is really high, around 40-55% depending on the genotype and area of cultivation. Today’s panorama and policies are pushing towards the exploitation of this crop because it is expected to be a valid alternative to fossil fuels for the production of biofuels, such as biodiesel, and for the valorization and use of abandoned and degraded land. Field experiment was conducted for analyzing the oil yield and oil content of four dwarf hybrids of castor, compared to a local genotype, selected by the University of Catania, Italy. The aim of the study was to evaluate the effect of different sowing dates on the oil content and oil yield of castor seeds. The analysis was conducted on primary and secondary raceme. The oil content was higher in the dwarf hybrids for the primary racemes, whereas for the secondary raceme the most productive one, in terms of oil content was GT. By analyzing also the oil yield (resulted from the multiplication of the oil content by the oil yield), the most productive genotype for the oil yield on average was G4, whereas SW3 was the sowing date with the highest value. Nevertheless, the combination genotype x sowing date had higher result for G3 SW3. Among the parameters studied, the genotype G2 shown a low level of tolerance to the low temperatures. Proceedings of the 31st European Biomass Conference and Exhibition, 5-8 June 2023, Bologna, Italy, pp. 296-299

Castor (Ricinus communis L.) is an oilseed species, which in southern Italy is cultivated as annual during the spring-summer period under irrigation, but in most temperate areas such as those of eastern coast of Sicily, it could be grown as semiperennial with no irrigation, by the adoption of autumnal sowings. A field experiment was conducted in southeastern Sicily with the aim of assessing plant surviving, seed yield and oil quality of four castor genotypes originating from different geographical areas (two Sicilian, one Tunisian and one Brazilian). The favorable climatic conditions allowed the plant to survive during the fall-winter period. Seed yield reached 3.45 t ha-1 on average of the two years and seed oil content ranged from 45% (Tunisian cultivar) to 48% ('Local RG 2' Sicilian genotype). Oil yield reflected the variation in seed yield. Genetic diversity for fatty acid composition and saponification number, iodine value and cetane number was evidenced. When ricinoleic acid is not taken into account, the oil of all genotypes satisfied the E.U. standards for biodiesel. The ricinoleic acid was the lowest (79%) in the Sicilian 'Local RG 2' and the highest (89%) in the Tunisian one, revealing a greater suitability of oil of the first genotype for biodiesel. In turn, the oil of Tunisian genotype could be exploited in other bio-based industrial sectors. The study also demonstrated that in the southeastern coast of Sicily autumnal sowings might be advantageous for castor grown as semi-perennial crop, mainly since they allow saving irrigation water.

Long-storage tomato is a drought-tolerant plant traditionally cultivated under no water supply in semi-arid areas of Italy. In 2009, physiological traits of ten "long-storage" tomato lines cultivated under no irrigation were screened for low soil water tolerance. Leaf relative water content (RWC), proline content and leaf transpiration (E) were measured throughout the growing season. Instantaneous leaf water use efficiency was also calculated on a single date, as the ratio between net photosynthesis (A) and E. Close relationships were observed among the physiological parameters, positive for E vs. RWC and inverse for RWC and E vs. proline. Results indicate that the increase in proline concentration involves a water stress tolerance, and genotypes more sensitive to soil water deficit respond to drought stress through less proline in leaves. Close significant linear relationships (positive with RWC and E, negative with proline) were also found between fruit yield and all the physiological parameters examined. Among them, the most reliable indicator for yield prediction under water restriction was leaf transpiration rate as measured at the flowering stage. The study made it possible to understand the complex relationships between physiological processes, drought tolerance, and plant productivity in long-storage tomato, and to identify those traits that regulate plant physiology under low water availability.

Plastic materials play a major role in the packaging sector for their properties and versatility. However, they are also a problem of environmental sustainability. The use of compostable bioplastics as an alternative to traditional non-biodegradable ones can mitigate the negative impact on the environment. In this work, a biobased compostable packaging system (polylactide trays and NatureFlex(TM) film) was evaluated for fresh-cut cherry tomato and compared with a traditional one (polyethylene terephtalate trays and polypropylene film). Quality aspects of fresh-cut tomatoes, structural stability under food contact conditions, mechanical and physical-chemical properties of sustainable packaging were investigated. Furthermore, to evaluate the effect of sterilization/ sanitization of food on the chemical-physical characteristics of packaging, the materials have been treated under UV hood or exposed to an oscillating electric field (radiofrequency). Data showed that the biobased compostable packaging for a prolonged shelf-life of fresh-cut cherry tomato has better properties that were surprisingly enhanced by the UV treatment1.

Predictions of future climate scenarios indicate that yields from perennial biomass crops (PBCs) growing in the Mediterranean region are likely to decline due to prolonged drought. Among PBCs, Miscanthus grasses with C4 photosynthesis combine high yield potentials and water use efficiencies. However, the standard commercial clone M. x giganteus (Mxg), with minimal stomatal regulation, is too sensitive to drought for reliable yields in the Mediterranean regions. This paper screened a diverse panel of thirteen Miscanthus genotypes (M. sinensis, M. floridulus, M. sacchariflorus and Mxg) to identify which types could maximize yield under summer drought conditions typical in the South Mediterranean climate. In the second growing season, significant differences were observed for plant height (from 63 to 185 cm), stem number (from 12 to 208 stems plant−1), biomass yield (from 0.17 to 6.4 kg DM plant−1) and whole crop water use efficiency (from 0.11 to 7.0 g L−1). Temporal variation in net photosynthesis, stomatal conductance, transpiration rate and instantaneous water use efficiency identified different strategies adopted by genotypes, and that genotypes selected from M. floridulus and M. sinensis were better adapted to rainfed conditions and could produce six times more biomass than the Mxg. These accessions are being used as parents in experimental breeding aimed at producing future seed-based drought resilient hybrids.

Castor (Ricinus communis L.) is an oilseed species that can be grown as a semi-perennial in Mediterranean environments, including the coastal areas of Sicily. The present study investigated the optimization of cultivation techniques for castor, with the crop being maintained over a two-year period, through the evaluation of different agronomical inputs in order to increase seed yield. The effects of irrigation (I) and nitrogen fertilization (N) on the seed and oil yield and their components were assessed in castor cultivated in a typical semi-arid environment. Four levels of irrigation (I0, I30, I60, and I100: 0, 30, 60, and 100% of crop evapotranspiration—ETm restoration, respectively) as the main plot and three levels of nitrogen fertilization (N) (0, 60, and 120 kg N ha−1) as the sub-plot were considered. Irrigation mostly affected the number of racemes per plant, the number of capsules per raceme, and the seed weight. The oil content was, on average, 39.2% and 45.6% for the first and second year, respectively. The highest seed yield was obtained by I100N120 treatment (4154.0 kg ha−1); however, the combination of a high soil nitrogen level (N120) and medium water availability (I60) resulted in satisfactory seed and oil yields. The reduction in the irrigation water to an intermediate level could be also an environmentally friendly strategy not significantly affecting yields.

Raising water and energy productivity in agriculture can contribute to reducing the pressure on the limited freshwater availability and non-renewable energy sources. Bioenergy perennial grasses are efficient from a water perspective and can afford a low-energy cultivation system; however, crop selection and cultivation practices for minimizing land use change and maximizing resource use efficiencies remain a challenging task in view of sustainable bioeconomy development. The present work investigated the soil water effect on a long-term plantation of Saccharum (Saccharum spontaneum ssp. aegyptiacum), a bioenergy perennial grass holding great promise for semiarid Mediterranean areas. The plantation was in its 13th year following establishment and was subjected to three levels of irrigation for three successive growing seasons. Regression models between crop water use (CWU) and productivity, biomass composition, energy, and water indicators showed different prediction curves. Raising CWU (from 230 to 920 mm) enhanced the dry biomass yield (from 14.8 to 30.1 Mg ha−1) and the net energy value (from 257.6 to 511 GJ ha−1). On the same CWU range, unirrigated crops improved the energy efficiency (from 99.8 to 58.5 GJ ha−1), the energy productivity (from 5.6 to 3.4 Mg GJ−1) and the water productivity (from 114.5 to 56.1 MJ m−3) by reducing the water footprint (from 8.7 to 17.8 m3 GJ−1). Biomass composition was also superior in unirrigated crops, as the lower heating value, structural polysaccharides, and the acid detergent lignin were higher, while ash and soluble compounds were lower. Present findings demonstrated the good yield levels and persistence of Saccharum, improving our knowledge of plant responses to changing soil water availability to maximize energy and conserve natural resources, paving the way for sustainable bioeconomy development in the Mediterranean area.