Given the growing interest in multipurpose hemp crop, eight monoecious cultivars were compared in a two-year trial for quantitative and qualitative yield in a Mediterranean environment characterized by a temperate and humid climate with hot summers. All hemp cultivars were evaluated for yield potential of (i) seed plus stem at seed maturity, and (ii) essential oil yield from inflorescences harvested at full flowering. The second goal was set to test the ability of cultivars to supply new seeds after the removal of inflorescence at full flowering. Among the cultivars, Fedora obtained the best results for seed (0.79 and 0.52 t ha⁻¹) and vegetable oil yield (0.17 and 0.09 t ha⁻¹) normally and with inflorescence removed plants, respectively. Futura, conversely, showed the best results for inflorescence (3.0 t ha⁻¹), essential oil (9 L ha⁻¹), and stem yield at seed maturity (8.34 t ha⁻¹), as means across the two years. The cultivars studied generally reached the grain-filling stage during a period that was drier and warmer than the average of the same multi-year period, and this negatively affected seed quality. The oil fatty acid composition was mainly composed of polyunsaturated fatty acids (75% on average) and not affected by the cultivar. In conclusion, although the hemp grower should always clearly know the main production objective of the crop, the monoecious cultivars available today allow a multipurpose use of hemp crop, improving the sustainability of the cultivation activity.

Due to its possible utilization in cosmetics, medicine and crop protection, as a valuable alternative to petrochemical-derived products, hemp essential oil is now considered a product with high value added and a promising marketing potential. This experiment was conducted with the aim of evaluating the effect of four different locations of Northern Italy during two years (four environments) and three hemp monoecious varieties on the production and quality of essential oils (EOs) obtained by inflorescences harvested at full flowering of female flowers. The highest inflorescence yield was obtained at Maiano 2017, where a superficial groundwater layer (1.5 m) was present, with values that ranged from 1.69 of Fedora to 2.06 t ha⁻¹ of Futura. EOs production ranged between 3.4 and 4.9 L ha⁻¹, affected mainly by the variety effect. The terpene in EOs, very similar between varieties and environments, was mainly composed of sesquiterpenes (caryophillene and humulene, as the most abundant) rather than monoterpenes (α-pinene, β-myrcene and trans-β-ocimene, in particular). Phytocannabinoids, and in particular cannabidiol (CBD), were not removed from tissues by the steam during hydrodistillation, and if this is confirmed by further experiments, the residual biomass, now considered as waste, could assume significant importance as a source for further utilization.

The seed yield in hemp (Cannabis sativa L.) is strongly influenced, besides by genotype, by environment and the genotype x environment interaction, so establishing the fitness and stability of hemp cultivars in multiple environments is necessary. The purpose of this study was to investigate the performance and degree of stability and variance of seed yield, the main related traits, and the correlation among the traits in five hemp monoecious cultivars cultivated in six different environments. The environments resulted from the combination of four locations, two years, and two delayed sowings in a Mediterranean area of north-eastern Italy, and the stability index of the weighted average of absolute scores (WAAS) was used in order to identify the most productive and stable genotypes on the basis of their deviation from the average performance across environments. In this studied area, early varieties, such as Fedora and Felina, proved to be the best performing and stable for seed yield and both increased their yield in correspondence to delayed sowing times, opening up the possibility of cultivating hemp as a second crop. Among the climate parameters, high temperatures during the early grain filling period led to a progressive decrease in seed yield. For a dual-purpose crop, a good compromise could be a late monoecious cultivar (like Futura, in the present experiment), which, if sown early, could certainly provide notable biomass production and acceptable seed yield.

The use of hemp (Cannabis sativa L.) essential oil (EO) has shown a significant increase in interest and use during recent years. In this work, a new and simple reversed-phase HPLC with photodiode-array (PDA) detector method has been developed and optimized for the detection and quantification of cannabidiolic acid (CBDA), cannabidiol (CBD), cannabinol (CBN), Δ9-tetrahydrocannabinol (Δ9-THC), and Δ9-tetrahydrocannabinolic acid (THCA). The cannabinoids were extracted from the EO by partition with n-hexane and water, followed by sonication, evaporation to dryness under nitrogen, and reconstitution with methanol:chloroform (9:1, v/v) before HPLC-PDA analysis. The method shows good selectivity and robustness, linearity in the range 0.5–100 mg L⁻¹ with R² higher than 0.999 for all cannabinoids analyzed, LOD of 0.11–0.16 mg L⁻¹, and LOQ of 0.35–0.48 mg L⁻¹. The recovery was between 78 and 100% and the intra-day and intermediate precision, expressed as relative standard deviation (RSD), was < 4% and 4–10%, respectively.

The consumption of cold‐pressed oil, such as linseed (Linum usitatissimum L.) and hemp (Cannabis sativa L.) oil has increased recently. In these oils obtained on the farm, a large number of components able to affect oil quality (mainly chlorophylls) are present. Given this, an experiment was conducted with the following aims: (1) to compare different bleaching methods by applying ultrasound waves and earths in cold‐pressed hempseed and linseed oils and (2) to evaluate the effect of different types (acid‐activated and natural) and amount (2% and 4%) of earths with different processing temperatures (60 and 80°C) in hempseed oil, utilizing a bleaching method with earths alone. Regarding the linseed oil, any bleaching methodologies adopted must not include ultrasound treatment, as the high temperatures reached determine high levels of oxidation to the detriment of the oil. Concerning the hemp oil, the natural earths, especially at farm level, should be preferred, because in addition to removing chlorophyll satisfactorily, when used at 4% even at the lowest temperature (60°C), an improvement of the stability and nutritional value (Vit. E) of the oil was observed.Practical applications: The use of ultrasound, applied together with bleaching earths, is considered an interesting and efficient bleaching method, in order to remove several pigments able to affect quality of many vegetable oils, with the exception of linseed oil. In fact, the use of ultrasound during the bleaching process determines a high oil temperature (120°C) and this, in an oil such as that of linseed characterized by a very high percentage (> 55%) of α‐linolenic acid, negatively affects the oil stability by the formation of high quantity of primary oxidation products, evidenced by very high peroxide values. In the bleaching activity carried out at farm level in particular, natural earths should be preferred to the acid‐activated ones. The latter, despite demonstrating an effective bleaching efficiency for few specific pigments, could increase the level of free fatty acids, reduce the antioxidant compounds (tocopherols) naturally present, and release undesirable contaminants in the oil.