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Highlights • Propagation by single-node stem cutting of giant reed (Arundo donax) was attempted. • Nutrients availability on the node plays a key role in rooting development. • In open field, the best period for node excision is July followed by May. • Nodes whose diameter exceed 2 cm showed higher rooting and plantlets development. • IBA resulted effective in promoting rooting in the worst excision dates. Abstract Giant reed (Arundo donax L.) is a warm-season, fast growing lignocellulosic crop suitable to Mediterranean and semi-arid environments. However, its sterility limits a cost-effective propagation along with environmental impacts associated with rhizome processing. In the present study, the effects of intrinsic (node size and node chemical composition) and extrinsic factors (node pretreatment with growth regulators) on root and shoot development were investigated under different excision time of node-cuttings in a controlled and open field conditions. Results indicated that nutrients availability of the propagation material plays a key role in rooting development. To enhance the success of giant reed propagation by single node stem-cuttings, the best period for node excision is July in open field trial, followed by the late spring (May). Nodes whose diameter exceed 2 cm resulted in higher rooting and plantlets development even in the less favorable excision dates. However, when big nodes are adopted in controlled environments even winter periods are eligible, being particularly useful for spring open field transplants of rooted plantlets. Among the growth regulators used in the present study, indole-3-butyric acid - IBA (in controlled environment) resulted effective in promoting rooting particularly in the worse excision date (April); in open field, IBA significantly improved rooting in the excision dates of February and May in the big nodes, and only in February in the small ones. NAA (1-naphthaleneacetic acid) was almost ineffective in enhancing rooting as compared to the control. The present study might open a new perspective to overcome one of the most significant drawbacks to establish giant reed, namely its agamic propagation. [ABSTRACT FROM AUTHOR]

Sustainable biomass production mostly relies on cultivation practices employing low external input supply. Wild germplasm might be suited for low-input techniques while providing enough output. The present study investigated four native Mediterranean perennial grasses ( Oryzopsis miliacea , Cymbopogon hirtus , Sorghum halepense , and Saccharum spontaneum L. ssp. aegyptiacum ), with an autumn and winter harvest regime in a 4-year field trial in Sicily (south of Italy). Species, cultivation year and harvest time had significant effects on whole season crop water use efficiency, energy efficiency and biomass quality. Species and cultivation year also significantly affected aboveground biomass yield and net energy yield. The total accumulated harvested yield over the 4-year experiment was the highest in Saccharum in both autumn and winter harvests (79.5 and 79.2 Mg DM ha −1 ), and the lowest in Cymbopogon (13.7 and 14.9 Mg DM ha −1 ). In both harvests, less than 20% of this total biomass was collected for all species at the first year (9.5–11.3% in Sorghum and 15.7–18.1% in Oryzopsis ). Peak biomass was reached at the third ( Saccharum and Sorghum ) or at the fourth year ( Orzyzopsis and Cymbopogon ) in autumn, and at the third year in winter harvest (all species). Water use efficiency was higher in the autumn than in the winter harvest (2.06 and 1.75 g L −1 , respectively), whilst the opposite was observed for energy efficiency (35.7 and 38.6 GJ ha −1 , respectively). Biomass structural compounds (hemicellulose, cellulose and acid detergent lignin) were higher in winter than autumn, while protein, lipid and ash contents were higher in autumn than winter. [ABSTRACT FROM AUTHOR]

Sustainable production of high value chemicals, biofuels and bioenergy relies on the replacement of fossil oil with low production cost feedstock and low environmental impact technologies. The present study evaluated the dry matter yield and feedstock properties of three different Arundo donax L. clones (Fontane Bianche, Piazza Armerina and Capo d’Orlando), two Miscanthus species ( M . × giganteus and M . sinensis “Goliath”) and Saccharum spontaneum L. spp. aegyptiacum (Willd.) Hack., all grown side-by-side in rainfed conditions for three consecutive years in semi-arid Mediterranean environment. Significant differences were observed among species, as well as among giant reed clones. F. Bianche and Saccharum were the highest yielding species in all growing seasons, followed by P. Armerina and C. Orlando, which did not differ. Out of Miscanthus, Giganteus overyielded Goliath. All species exhibited the highest dry matter yields in the wettest growing season. Saccharum and giant reed clones showed higher biomass water content than both Miscanthus. Ash content was the lowest in Giganteus and the highest in F. Bianche. Low heating value was the highest in Saccharum, both Miscanthus and giant reed P. Armerina. Generally, the bulk density was greater in giant reed and Saccharum than Miscanthus. Cellulose was the highest in both Miscanthus and hemicellulose in Saccharum. Lignin content was the lowest in giant reed clones. Several significant correlations occurred between biomass yield and raw material characteristics, as well as within feedstock properties. To support the development of a suitable bioenergy chain based on perennial grasses, besides biomass yield, feedstock properties should be rigorously considered. Further research is still required in crop management practices, logistic and technology front in order to tackle bottlenecks for improved quality of herbaceous biomass. [ABSTRACT FROM AUTHOR]

Within a framework of renewed interest in crambe ( Crambe abyssinica Hochst ex R.E. Fries) sourcing raw materials for the bio-based industry, the adaptability and productive performances of this oil crop have been evaluated under contrasting Mediterranean environments (i.e., a fertile site in the northern part of Po valley vs. a semi-arid site of southern Sicily) during two consecutive growing seasons, aiming at its possible stable introduction in this area. The trial set in northern Italy compared three commercial varieties of crambe (Galactica, Nebula and Mario) in spring sowing, while in southern Italy only the var. Mario was tested with autumn sowing. Regardless of location and variety, thermal time for maturity was quite stable (1200–1400 °C), and the crop provided satisfactory seed yields (grand mean 2.29 Mg hulled seeds ha −1 ), with average oil content of ∼400 g kg −1 (on dehulled seeds) and ∼52% of erucic acid. Significantly higher seed and oil yields were reached in northern than in southern Italy. Furthermore, crambe thermal use efficiency (THUE) was also higher in the north than in the south, possibly due to better environmental adaptability of the crop. The limited intraspecific variability within crambe was confirmed, with better productive performances showed by the domestic selection Mario. Promising traits were revealed in Nebula, showing greater seed weight, root length density and area, and thinner roots, although the root growth of crambe was generally modest compared with modern high erucic acid rapeseed hybrids. Available crambe varieties could be efficiently included in crop rotations across a wide range of environments within the Mediterranean basin. The short growth cycle represents an outstanding added value for this species, allowing the avoidance of prolonged drought and heat stress typical of late spring/early summer months under the Mediterranean climate. However, increased yields are needed to meet the market requests; nonetheless, the little genetic variability suggests that there is large scope for future breeding improvements, maybe exploiting advanced techniques to improve the existing genetic resources. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Kenaf (Hibiscus cannabinus L.) is a warm-season annual plant grown in the past for the bast fiber. In the last decades, this crop has been re-evaluated for many alternative industrial uses of its biomass (i.e., production of biofuel, biocomposite materials, bioproducts). In this paper, the interaction effects of sowing time (May and June) and plant population (P20 and P40, 20 and 40 plants m-2, respectively) on yield and some biomass parameters were analysed in two cultivars of kenaf (Tainung 2-TAI, and Everglades 41-EVER), in a two-year experiment in semi-arid environment, under irrigation. The aim of this paper was to assess the potential of this crop as an energy or industrial feedstock, in south Mediterranean environment where was never cultivated. Overall, plants from late sowing (June) were smaller and with less node, those at high plant density (P40) were thinner. In both seasons, plants of TAI were taller than those of EVER. Plant weight was greater in P20, and an overall significant negative correlation was found between plant weight and actual plant density (r = −0.76 **). The shift of sowing time reduced significantly the final dry biomass. Crop productivity did not change with plant density, however a higher percent bark corresponded to P40 in both years, cultivars, and sowing times, A simple model was developed to simulate and predict the course of LAI and dry biomass (AGB) with time, using field dataset of 2004, for calibration, and dataset of 2005, for validation. The minor response of LAI to plant population in 2005 led to a low accuracy of model approximation. This result suggests that other variables that are not considered in the model, may influence LAI. Nevertheless, the overall AGB model approximation of observed value was accurate. Concluding, the results revealed that biomass productivity is more influenced by sowing time than by plant density. However, plant population has been found to regulate the proportion of bark/core layers, with important implications for industrial (energy and pulp production) purposes. Further improvements on the simple model developed, e.g., including soil water nitrogen balances submodels, may be done, in order to explore the possibility of using the model under different conditions of soil water content and nitrogen fertilization. • Sowing time and plant density effects were studied in two cultivars of kenaf. • Dry biomass yield was significantly reduced shifting sowing from May to June. • Dry biomass did not change with plant density (20 or 40 plants m-2). • The % incidence of bark on core weight was greater in plants at higher density. • A simple model was developed to simulate and predict LAI and biomass in kenaf. [ABSTRACT FROM AUTHOR]

The aim of the present work was to evaluate the effect of soil water availability and nitrogen fertilization on yield, water use efficiency and agronomic nitrogen use efficiency of giant reed ( Arundo donax L.) over four-year field experiment. After the year of establishment, three levels for each factor were studied in the following three years: I 0 (irrigation only during the year of establishment), I 1 (50% ETm restitution) and I 2 (100% ETm restitution); N 0 (0 kg N ha −1 ), N 1 (60 kg N ha −1 ) and N 2 (120 kg N ha −1 ). Irrigation and nitrogen effects resulted significant for stem height and leaf area index (LAI) before senescence, while no differences were observed for stem density and LAI at harvest. Aboveground biomass dry matter (DM) yield increased following the year of establishment in all irrigation and N fertilization treatments. It was always the highest in I 2 N 2 (18.3, 28.8 and 28.9 t DM ha −1 at second, third and fourth year growing season, respectively). The lowest values were observed in I 0 N 0 (11.0, 13.4 and 12.9 t DM ha −1 , respectively). Water use efficiency (WUE) was significantly higher in the most stressed irrigation treatment (I 0 ), decreasing in the intermediate (I 1 ) and further in the highest irrigation treatment (I 2 ). N fertilization lead to greater values of WUE in all irrigation treatment. The effect of N fertilization on agronomic nitrogen use efficiency (NUE) was significant only at the first and second growing season. Giant reed was able to uptake water at 160–180 cm soil depth when irrigation was applied, while up to 140–160 cm under water stress condition. Giant reed appeared to be particularly suited to semi-arid Mediterranean environments, showing high yields even in absence of agro-input supply. [ABSTRACT FROM AUTHOR]

Abstract: In the present study the effect of temperature, reaction time and dilute oxalic acid (OA) concentration during steam-pretreatment of Miscanthus × gigantueus has been evaluated using the combined severity factor (CS). At the highest CS glucan and lignin content in the water insoluble fraction (WIF) increased, while xylan content decreased. While glucose recovery in the water soluble fraction (WSF) was found at low concentration when mild CS were used (≤5.0 g L−1 at CS ≤ 2.17), xylose and arabinose concentrations were higher at low-mild CS (1.58–2.17) with a concentration peak at CS 2.03 (39.9 and 3.2 g L−1 for xylose and arabinose, respectively). The decrease in pentoses coincided with inhibitory formation in the WSF, namely acetic acid, furfural, HMF and phenolic compounds. Glucan conversion rose from 46.1% at CS 1.54 to 91.2% at CS 2.76. Likewise, maximum ethanol concentration was achieved at CS 2.76, corresponding to 20.2 g L−1 and a volumetric ethanol productivity of 0.28 g L−1 h−1. Negative correlations have been found between xylan vs. glucan conversion and xylan vs. ethanol production, suggesting that decreasing the xylan content in WIF increases both saccharification rate and ethanol concentration (R 2 0.91 and R 2 0.93, respectively). On the other hand, a positive correlation was found between ethanol production and glucan conversion (R 2 0.93). Fermentation of WSF by Scheffersomyces (Pichia) stipitis CBS 6054 at CS 1.54 produced 12.1 g L−1 of ethanol after 96 h incubation with a volumetric ethanol productivity of 0.13 g L−1 h−1. [Copyright &y& Elsevier]

Highlights: [•] Giant reed biomass has been pretreated with dilute oxalic acid. [•] Enzymatic hydrolysis and SSF have been optimized through RSM. [•] Enzymatic hydrolysis showed a glucan conversion of 95%. [•] Ethanol production using Schefferomyces (Pichia) stipitis CBS 6054 reached 18gl−1. [•] Maximum theoretical ethanol yield was 75%. [ABSTRACT FROM AUTHOR]

Abstract: Biomass pretreatment is essential to overcome recalcitrance of lignocellulose for ethanol production. In the present study we pretreated giant reed (Arundo donax L.), a perennial, rhizomatous lignocellulosic grass with dilute oxalic acid. The effects of temperature (170–190 °C), acid loading (2–10% w/w) and reaction time (15–40 min) were handled as a single parameter, combined severity. We explored the change in hemicellulose, cellulose and lignin composition following pretreatment and glucan conversion after enzymatic hydrolysis of the solid residue. Two different yeast strains, Scheffersomyces (Pichia) stipitis CBS 6054, which is a native xylose and cellobiose fermenter, and Saccharomyces carlsbergensis FPL-450, which does not ferment xylose or cellobiose, were used along with commercial cellulolytic enzymes in simultaneous saccharification and fermentation (SSF). S. carlsbergensis attained a maximum ethanol concentration of 15.9 g/l after 48 h at pH 5.0, while S. stipitis, at the same condition, took 96 h to reach a similar ethanol value; increasing the pH to 6.0 reduced the S. stipitis lag phase and attained 18.0 g/l of ethanol within 72 h. [Copyright &y& Elsevier]

Abstract: Saccharum (Saccharum spontaneum L. ssp. aegyptiacum (Willd.) Hack.), is a rapidly growing, wide ranging high-yield perennial, suitable for second generation bioethanol production. This study evaluated oxalic acid as a pretreatment for bioconversion. Overall sugar yields, sugar degradation products, enzymatic glucan hydrolysis and ethanol production were studied as effects of temperature (150–190°C), reaction time (10–40min) and oxalic acid concentration 2–8% (w/w). Time and temperature were combined into a single parameter, Severity Factor (SF) [Log(R 0)], and related to oxalic acid using a response surface methodology. Maximum total sugar yield was attained at a SF of 2.93 and 6.79% (w/w) oxalic acid, while maximum formation of sugar degradation products was observed at the highest SF (4.05) and 5% (w/w) oxalic acid. These were also the conditions for maximum simultaneous saccharification and fermentation (SSF) of the residual solids. Commercial cellulases and Saccharomyces cerevisiae attained 89.9% glucan conversion and 17.8g/l ethanol. Pichia stipitis CBS 6054 fermented hemicellulosic hydrolysates from less severe conditions to ethanol with a yield of 0.35 (g e/g s). Maximal product yields were 69% of theoretical value and 90% of the SSF conversion efficiency for hydrolysate fermentation and SSF, respectively. [Copyright &y& Elsevier]

• Long-term perennial grasses were compared in two locations and four growing seasons. • The main driving factor of bioethanol production was the biomass yield. • Optimization of harvest time allowed to gain more ethanol per unit mass. • Giant reed was the most chemically consistent feedstock among study factors. • Bioethanol biorefineries may gain fourfold the energy invested. Advanced biofuel production requires feedstock with specific composition in terms of quantity and quality. Decisions about the harvest time of perennial energy grasses have important implications for bioconversion process as well as for the life-span of the plant stand. Four-year data from long term-field trials were used to identify the optimal crop-specific harvest date (autumn vs. winter), in relation to advanced biofuel production. Three different perennial energy grasses (i.e., switchgrass, giant reed and miscanthus) were grown at Bologna and Catania (Italy), under northern and southern Mediterranean climate, respectively, adopting a low input management. In addition to the biomass yield and composition, the net energy value (NEV) from agricultural activities, and the energy return on investment (EROI) at the biorefinery gate was also evaluated. At Bologna, switchgrass biomass yield and quality (hemicellulose, cellulose and acid detergent lignin – ADL) were significantly enhanced when harvested in winter. At Catania, giant reed productivity, cellulose and ADL content were unaffected by harvest date, while hemicellulose and ash content decreased in winter. Biomass composition of miscanthus was more stable in Catania than Bologna, however, yield and components resulted significantly higher in Bologna than Catania, due mainly to the more even precipitation distribution throughout the vegetative crop development. The NEV was positive for all energy crops, treatments and locations, with the highest value for miscanthus grown at Bologna. The EROI of lignocellulosic bioethanol ranged from 4.16 for switchgrass in the autumn harvest at Bologna to 4.37 for miscanthus grown at Catania, which showed also the highest theoretical bioethanol production (169.2 kg h−1) at a feeding rate of 300 kg h−1 of raw material. Nonetheless, miscanthus grown at Bologna attained the highest bioethanol yield (12,254 L ha−1). This study proved that investigated perennial grasses are worth to be grown as lignocellulosic feedstock under low input for at least one decade, upon which Mediterranean region biorefineries may gain fourfold the energy invested. [ABSTRACT FROM AUTHOR]

Side by side biomass productivities, harvesting time (autumn vs. winter) and frequency (annual vs. biennial) of three perennial grasses were compared under northern and southern Mediterranean climates. Miscanthus ( Miscanthus × giganteus Greef et Deu.) was compared to giant reed ( Arundo donax L.) in Catania (37°24′N, 15°03′E), and to switchgrass ( Panicum virgatum L.) in Bologna (44°55'N, 11°45′E). Generally, giant reed produced about 50% higher biomass than miscanthus in Catania. Miscanthus almost halved biomass productivity in the driest year, while giant reed reduced biomass yield by only 30% under the same conditions. In Bologna, miscanthus and switchgrass produced similar amounts of cumulative biomass over 6 years. Switchgrass kept more stable annual yields than miscanthus, which, however, evidenced a higher potential under favorable climate conditions. Autumn harvest significantly reduced biomass productivity and quality (moisture content, ashes, cellulose and hemicellulose), particularly under South Mediterranean climate. In Catania, autumn biomass was 50% (giant reed) to 85% (miscanthus) lower than winter biomass, while in Bologna, autumn cut reduced switchgrass yield by 20%. Biennial harvesting resulted in almost 40% lower cumulative biomass yield than annual cut, after 6 years. [ABSTRACT FROM AUTHOR]

Abstract: Fibre hemp can be grown under a wide range of agro-ecological conditions, but it requires special attention for several physiological features and crop management. A management strategy in order to reduce inputs and thus achieve acceptable yield could be achieved optimizing sowing time. With this respect, the effects of sowing date on hemp biology and yield was studied, using two monoecious and two dioecious genotypes. Field experiments were carried out in two subsequent years (2003–2004) in South of Italy, using drip irrigation system. Sowing time, in the two year period, ranged between March 10th and July 22nd. Optimal sowing time was observed between the end of April and the first three weeks of May; in that range, the dioecious Fibranova yielded the most in terms of aboveground biomass and stem dry yield, followed by Tiborszallasi, while the two monoecious showed the lowest yield. On the contrary, before and after that period, the shorter day length caused an early floral induction that strongly reduced stem and fibre elongation, and thus aboveground dry biomass and consequently stem yields. Based on this study a simulation model focusing on flowering prediction in Mediterranean environment was developed. [Copyright &y& Elsevier]

The aim of the present work was to ascertain, in a two-year field trial, leaf gas exchange, plant water status and radiation use efficiency of giant reed ( Arundo donax L.) under different nitrogen fertilization and soil water availability in semi-arid Mediterranean area. Three levels of nitrogen (0, 60 and 120 kg N ha −1 ) and three levels of soil water availability (rainfed, 50% ETm restitution and 100% ETm restitution) were compared. Throughout the crop growing season significant effects of soil water availability, nitrogen fertilization and time of measurement on net photosynthesis ( A ), transpiration rate ( E ), stomatal conductance (gs), canopy temperature (Tc), midday (ψ M ) and predawn leaf water potential (ψ PD ) were found. Significant interactions of soil water availability x time of measurement were also observed, while nitrogen x time of measurement was significant only for A , gs, E and ψ M . Radiation use efficiency (RUE) was lowest in rainfed and no-nitrogen fertilization (1.40 and 1.26 g MJ −1 in 1998 and in 1999, respectively) and highest in 100% ETm and 120 kg N ha −1 in both years (1.78 and 1.94 g MJ −1 in 1998 and in 1999, respectively). The fraction of intercepted PAR approached the asymptote when leaf area index was greater than 4.0, irrespective of soil water availability and nitrogen fertilization. The extinction coefficient ( k ) ranged from 0.38 to 0.44. Present results may have practical applications to help maximize physiological performances with improved WUE, optimized resource use efficiency and reduced irrigation demands. [ABSTRACT FROM AUTHOR]

Research is needed to look for plants or lines that can thrive on soils affected by water deficit or other constraints. The present work investigated the potentiality of Saccharum spontaneum L. spp. aegyptiacum (Willd.) Hack., a lignocellulosic, perennial, rhizomatous, no-food crop in semi-arid Mediterranean area. A 3-year field trial was carried out with the aim to evaluate its physiology, biomass yield, water use efficiency, and biomass quality under different soil water availability. During 2011/2012, 2012/2013, and 2013/2014 growing seasons (hereinafter referred as 2011, 2012, and 2013, respectively), three levels of maximum evapotranspiration restitution (ETm) were compared: I 100 (100% ETm restitution), I 50 (50% ETm restitution), and I 0 (rainfed condition). Net photosynthesis, stomatal conductance, and transpiration rate were strictly related to the available soil water content (ASWC), with maximum gas exchange at field capacity. However, gas exchange between plants and atmosphere was also measured when ASWC was close to wilting point. Biomass dry matter (DM) yield and main morpho-biometric traits (e.g., stem height and basal stem diameter) were significantly affected by ASWC. A non-linear model showed that maximum DM yield, 37.86 Mg ha −1 , can be achieved when 1150 mm of water were used by the crop. Water use efficiency (WUE) was always highest in rainfed condition ( I 0 ), however, only in 2013 I 0 was significantly higher than I 50 and I 100 (5.89 g L −1 vs 4.26 and 3.33 g L −1 ). Within the variables employed, a linear model showed that WUE was negatively related to crop water use (CWU). The fiber content was not affected by the irrigation treatments. In the average, hemicellulose, cellulose, and lignin accounted for 23.9 (% w/w), 35.0 (% w/w), and 19.9 (% w/w), respectively. On the other hand, moisture and ash content, bulk density, low heating value, and ash melting point resulted significantly affected by the treatment. Present results suggested that S. spontaneum spp. aegyptiacum possesses a range of agronomically desirable traits of biomass crop: C4 plant, high biomass yield, active assimilation rates during drought–stress periods, able to use water efficiently, and satisfactory biomass quality. [ABSTRACT FROM AUTHOR]

Highlights: [•] Monoecious and dioecious hemp were studied in Mediterranean semi-arid environment. [•] Later dioecious showed the highest aboveground and stem DM yield (tha−1) [•] WUE ranged between 2.73gl−1 in good water and 3.45gl−1 in water stress conditions. [•] Optimum of photosynthetic rate was achieved at 24°C. At 43°C hemp growth ceased. [•] As soil water availability increased, RUE increased and light extinction coefficient (k) decreased. [ABSTRACT FROM AUTHOR]

• Castor might be grown as rainfed crop in semi-arid Mediterranean environments. • Autumn or winter sowings allowed to increase phenological intervals and seed yield. • Photoperiod corrected growing degree unit equations showed the lowest variability. • Suitable areas for autumn sowings were identified in Sicily. Castor (Ricinus communis L.) is an oilseed crop holding great promise for semi-arid environments. In regions where minimum temperature during winter is high enough to allow plants to survive, it would be worth to explore the adaptability of the species by performing autumn sowings, thus enabling rainfed cropping systems. A two-year field experiment under different sowing times (from November to June) was conducted in Southern Italy using castor Hy. Hazera. Autumnal sowings extended the plant vegetative period; nevertheless, flowering was simultaneous with all sowing dates. Only with the latest spring sowing (that of June) both floral induction and seed ripening were postponed. Seed yield with January and February sowings was the highest (3.92 Mg/ha on average). Using the wide variability of temperature and photoperiod conditions of the different growing periods, thermal and photothermal sums to predict the length of the main phenological intervals were calculated using different models. Overall, the best predicting model was that using sums of thermal units from minimum temperatures > 8 °C and maximum temperatures of 30 °C minus the degrees exceeding 30 °C, multiplied by photoperiod. The model allowed to develop zonation maps predicting the latest sowing date and the earliest seed ripening date in Sicily for autumn-spring and spring-summer growing season. The zonation procedure indicates that castor can be sown in autumn in coastal areas, while spring sowings are more suited to colder inland and hilly areas of Sicily. The work might find practical application to individuate suitable Mediterranean areas to grow castor in winter sowings. [ABSTRACT FROM AUTHOR]