Soil physical and chemical properties play a central role in plant growth, influencing the availability of air, nutrients, and water. The aim of this two-year study was to evaluate the effect of soil texture and chemical properties (pH, electrical conductivity, organic carbon, organic matter, total, and active lime) on saffron (Crocus sativus L.) growth, yield, and quality. Corms were planted in pots filled with seven different soil textures obtained mixing an increasing quantity (33% and 66%) of sand to a clay soil (S1) and to a clay loam soil (S2) compared to a full (100%) sandy soil as a control (S7). A randomized complete block design comprising of seven pots with different types of soil (S1, S2, S3, S4, S5, S6, and S7) replicated three times was used. The results showed that the highest flower number (320.3 n m⁻²), stigma yield (2.0 g m⁻²), daughter corm production (7.9 kg m⁻²), and horizontal diameter (3.1 cm) were derived from S3 and S4 soils. These were characterized by a loam and sandy-loam texture, not very calcareous, with a sub-alkaline and neutral pH, low electrical conductivity, a content of organic matter between 5.46 and 8.67 g kg⁻¹, and a content of active lime between 21.25 and 26.25 g kg⁻¹. According to International Organization for Standardization (ISO) references, although all spice samples belonged to the first qualitative category, S1, S3, and S2 soils recorded the highest value for coloring power (290.5, 289.1, and 287.6 A^1%_1cm 440 nm, respectively). The highest values of bittering (109.2 A^1%_1cm 257 nm) and aromatic (26.6 A^1%_1cm 330 nm) power were reached by S3 soil. Positive correlations were found both between color with clay and organic matter, and aroma with total calcium carbonate. In conclusion, the assessment of soil conditions is particularly important to obtain the best saffron performance in terms of stigma and daughter corms yield as well as spice qualitative traits.

The characterization of C. sativus ecotypes is of great interest for preserving them from a possible genetic erosion due to the decrease of European cultivation surface. In this study, we evaluated four ecotypes from Italy (Sardinia and Abruzzo), Spain (Castilla-La Mancha), and Greece (Kozani) in order to detect the existence of variability and promote the biodiversity of this crop. Thirty-one traits related to saffron flowering, flower morphology, production of spice and daughter corms, vegetative development (leaf and corm traits), and spice quality, were evaluated. In addition, a genetic analysis through three PCR-based approaches, SSRs, RAPD, and SRAP was assessed. Results highlighted a phenotypic variation among ecotypes during two consecutive years. All the studied parameters were influenced by the ecotype except for the stamen length, color coordinates of tepals, leaf length, and leaf number per plant. Sardinia had a longer flowering interval, earlier flowering, and higher spice yield and quality than the other corm origins. The maximum values of morphological traits, such as stigma length, dry weight of stigmas, tepals, flowers and leaves, leaf area, and daughter corm weight were observed in the Abruzzo ecotype. Principal component analysis (PCA) showed a clear separation among ecotypes, in which Sardinia and Spain showed more similarities than Abruzzo and Kozani. Significant negative correlation was found between days to flower with stigma yield and quality. However, we could not find molecular markers discriminating among corm origins. In conclusion, this study suggests the importance of C. sativus ecotypes as precious source of biodiversity and bioactive compounds, and of their enhancement as fundamental prerequisite for a sustainable development strategy and as an agricultural diversification opportunity for growers.

The propagation of Crocus sativus L. relies exclusively on corm multiplication. As underground storage organs, corms are susceptible to a wide range of pathogens, environmental stresses, and diseases, making traditional propagation methods often ineffective with the loss of valuable material. In vitro propagation offers an alternative for the saffron culture under controlled conditions. In particular, the innovative application of the Temporary Immersion System (TIS) represents a technological advancement for enhancing biomass production with a reduction in operational costs. The current study utilized the Plantform™ bioreactor to propagate in vitro saffron corms from the ‘Abruzzo’ region (Italy), integrating machine learning models to assess its performance. The evaluation of saffron explants after 30, 60, and 90 days of culture showed a marked improvement in growth and microcorm production compared to conventional in vitro culture on semisolid medium, supported by the machine learning analysis. Indeed, the Random Forest algorithm revealed a predictive accuracy with an R² value of 0.81 for microcorm number, showcasing the capability of machine learning models to forecast propagation outcomes effectively. These results confirm that applying TIS in saffron culture could lead to economically viable, large biomass production within a controlled environment, irrespective of seasonality. This study represents the first endeavor to use TIS technology to enhance the in vitro propagation of saffron in conjunction with machine learning, suggesting an innovative approach for cultivating high-value crops like saffron.

The abandonment of farmland in Europe is a significant issue due to its environmental, socio-economic, and landscape consequences. This tendency mainly impacts marginal and inner areas, located far from large urban districts, because of biophysical and/or socio-economic factors. Although European and national regulations try to turn the fragility of these territories into an opportunity for sustainable development, many of these areas, especially in southern Europe, continue to suffer socio-economic disparities. For this reason, it is necessary to consider regional and district-wide initiatives that can economically revitalize marginal areas while safeguarding their natural capital. Alternative cropping systems, capable of optimizing the quality of some food crops, can play an essential role in the economic development of populations living in marginal areas. These areas, represented by inland zones often abandoned due to the difficulty of applying mechanized agriculture, can represent an opportunity to rediscover sustainable and profitable practices. Among the high-value crops, saffron (Crocus sativus L.), “red gold” and “king of spices”, stands out for its potential. Indeed, thanks to the use of tuff tubs, a more eco-sustainable choice compared to the plastic pots already mentioned in the literature, it is possible to improve the quality of this spice. Furthermore, Crocus sativus L. not only lends itself to multiple uses but also represents a valid opportunity to supplement agricultural income. This is made possible by its high profitability and beneficial properties for human health, offering a way to diversify agricultural production with positive economic and social impacts. It is known that the saffron market in Italy suffers from competition from developing countries (Iran, Morocco, India) capable of producing saffron at lower costs than European countries, thanks to the lower cost of labor. Therefore, this study seeks to identify marginal areas that can be recovered and valorized through an eco-sustainable cultivation system with the potential to enhance the quality of this spice, making it unique and resilient to competition. Specifically, this paper is organized on a dual scale of investigation: (a) at the local level to demonstrate the economic-ecological feasibility of saffron cultivation through the adoption of an alternative farming technique on an experimental site located in Tricarico (Basilicata—Southern Italy, 40°37′ N, 16°09′ E; 472 m. a.s.l.) that, although fertile, is not suitable for mechanized cropping systems; (b) at the regional level through a spatially explicit land suitability analysis to indicate the possible location where to export saffron cultivation. The final map, obtained by combining geo-environmental variables, can be considered a precious tool to support policymakers and farmers to foster a broad agricultural strategy founded on new crop management systems. The adoption of this alternative agroecological system could optimize the use of land resources in the perspective of increasing crop productivity and profitability in marginal agricultural areas.

Plant biostimulants are used to promote plant growth by increasing tolerance to abiotic stressors and improving the efficiency of natural resource use. In the present two-year research (2022–2023 and 2023–2024), the effects of biostimulant foliar applications on the morphological parameters, fresh and dry yields, antioxidant capacity, total phenolic content, and chemical composition of the essential oil of thyme (Thymus vulgaris L.) were studied. For this purpose, four commercial biostimulants, Biostimol Plus + Peptamin-V Plus^®, Acadian MPE^®, Megafol^®, and BlueN^®, were evaluated on thyme cultivated in field conditions. The experiment was laid out in a randomized block design with five treatments and with three replications. During the second growing season, the plants treated with BlueN^®, composed of the bacteria Methylobacterium symbioticum SB23, showed the highest plant weight (152.1 g plant⁻¹), fresh biomass yield (501.9 g m⁻²), and dry yield (172.2 g m⁻²). BlueN^® was the biostimulant that also obtained the highest essential oil yield in both years (0.47 and 0.53%), and for all biostimulants, the amount of thymol and carvacrol increased in the second year, especially with Megafol^® (63.75 and 3.16%). The antioxidant capacity was enhanced in the second year by all biostimulants, according to the ABTS assay, but in particular, by BlueN^® and BPPVP (26.97 μmol/g and 25.01 μmol/g), while the phenolic content was higher in the first year, especially with BlueN^® (65.98 mg GAE/g Extract). The other biostimulants had less intense effects. In conclusion, the biostimulants influenced some characteristics of the essential oil, but the greatest influencers were BlueN^®, Megafol^®, and BPPVP.