Farmers’ interest in renewable raw materials such as hemp (Cannabis sativa L.) fibres has recently increased, but hemp productivity is strongly affected by genotype and environment conditions. A 3-year field experiment was conducted under Mediterranean environment in northern Greece to evaluate the productivity (regarding fibres and seeds) of six monoecious hemp varieties. The vars. Futura 75 and Bialobrzeskie provided the greatest (p < 0.01) fibre productivity (4.57 and 4.27 t ha⁻¹, respectively), which were 77.1% and 65.5%, respectively, greater than that of the least productive var. Fedora 17. However, the vars. Santhica 27, Tygra and Bialobrzeskie provided the highest (p < 0.05) seed yield (2.7, 2.9 and 2.6 t ha⁻¹, respectively), which were 28.6%, 38.1% and 23.8%, respectively, greater than that of the least productive var. Futura 75. Hemp fibre yield was strongly positively correlated with total biomass (R² = 0.8612) and stem biomass yield (R² = 0.9742), while it was inversely correlated with fibre strength (R² = 0.424). Hemp seed yield was not correlated with the hemp plant density, height, total biomass or stem biomass yield. The six hemp genotypes evaluated in the study had Δ9-tetrahydrocannabinol (THC) content lower than 0.2% satisfying the European legislation requirements for industrial hemp varieties. The results of the study indicated that, under Mediterranean conditions (northern Greece), the var. Bialobrzeskie showed high productivity, as averaged across years, for both fibres and seeds. This result is very helpful for farmers which should prefer hemp varieties of dual-purpose production (stems and inflorescences or stems and seeds) adapted best to their local environment.

Tobacco (Nicotiana tabacum L.) is an important industrial crop grown in more than one hundred countries worldwide, with high adaptability on a great variety of soils, and under quite diverse climatic conditions. Information regarding the chemical composition of tobacco leaves is important for the tobacco industry because it generally may exhibit important differences among different locations. In this study, five oriental and six flue and air-cured type tobacco varieties were cultivated in five areas of Greece for three cultivation periods, in order to evaluate the effect of these three factors (variety, area, and period), on the yield as well as nicotine content, and sugar and nitrate content of the produced leaves. For the oriental type varieties, the results showed that the area exhibited significant interaction with both variety and the cultivation year, related to the yield. Concerning the nicotine content, no significant differences were observed regarding the areas of experimentation; however, it significantly varied within the varieties. In particular, the nicotine content of Katerini 53 exhibited a significant difference compared to Xanthi 2A, which had the highest content of all tested varieties. Sugar content was affected significantly by all the factors considered, with the area of Xanthi exhibiting lower values compared to all other varieties. Regarding the flue and air-cured varieties, the only interaction that was found to be statistically significant, when the yield was assessed, was between the cultivation year and the area. It was found that there was a significant interaction between cultivation year and area for the nicotine content as well. Furthermore, cultivation year and variety significantly affected the sugar content. The varieties Burley 21E and NC7LC gave the lowest sugars. In general, it was observed that in the case of the oriental type varieties, the variety adaptation in specific regions resulted in higher yields, with the paradigmatic example of the variety Katerini 53 in the Katerini area, and Xanthi 81 in the Xanthi area. On the other hand, in the case of the flue and air-cured varieties, Karditsa was the area that exhibited the lowest yield of all tested varieties.

Industrial hemp is mainly cultivated for its fibers aimed at the production of textiles, paper, and cordage; the inflorescences for medicinal purposes; and the seeds are used by the food industry due to their high nutritional and functional matrix of protein, fiber, lipids, and microelements. Hemp seed oil (HsO) is a unique source of polyunsaturated fatty acids, with a phenomenal ω6:ω3 ratio of 2.5–3.0, significantly enhancing human health when consumed daily. HsO is mostly obtained through cold pressing due to minimal thermal treatment, and although of lower yield compared to solvent extraction, it presents higher quality lipid fractions and organoleptic characteristics such as color, taste, flavor, and density. Although HsO is a powerful source of polyunsaturated fatty acids, antioxidants, and phytosterols, its production lacks standardized quality control parameters, except for THC, which is subject to EU legislation. Therefore, it is essential to build up a quality protocol system for standardizing seed conservation, oil extraction methods, and quality parameters. This review aims to display an overall nutritional framework of the HsO and encourage further research into its use in the food value chain.

Cotton, a high-value crop of primary financial importance for Greece, is directly affected by a wide range of environmental parameters, and water scarcity threatens the sustainability of irrigated cotton production in many regions around the world. Reducing inputs with an appropriate cultivar may not decrease cotton production and fiber quality while improving sustainability. To investigate cotton varietal responses to water stress and lack of nutrients, in the climate of north Greece, a three-year experiment was conducted in Thessaloniki, Greece. Four cotton cultivars (three of Greek origin and one from Africa) were cultivated under four irrigation (normal and reduced by 75%, 50%, and 25%) and two fertilization levels (normal and 50%). The effect of these treatments on productivity and quality were estimated, with the final objective being the reduction of inputs and more sustainable cotton production. Cotton producers are dealing with a cost price squeeze and the present study demonstrates that reducing the fertilization inputs even by half and the reduction of irrigation by 25% has no significant effect neither on yield nor on the main technological characteristics. This highlights the fact that a more sustainable use of inputs, contrary to common management, will have almost the same yield and even increase the farmer’s income.

Industrial hemp is a continuously expanding crop; however, there has been limited research on its herbicide selectivity and weed control. Pendimethalin, s-metolachlor and aclonifen at 1137.5, 960 and 1800 g a.i. ha⁻¹, respectively, were applied in field experiments in 2022 and 2023 in Greece to study the response of industrial hemp to pre-emergence (PRE) herbicides and record their efficacy on weeds. In 2023, each PRE herbicide was followed by the postemergence application of cycloxydim at 200 g a.i. ha⁻¹ due to infestation of Sorghum halepense. In 2022, retardation in hemp growth was recorded by all PRE herbicide treatments, with there being a slight reduction in stand counts by pendimethalin and s-metolachlor and leaf yellowing by aclonifen in one the experiments. In 2023, no reductions in crop establishment and plant height were recorded, whereas leaf discoloration caused by aclonifen was less evident; cycloxydim did not affect hemp and perfectly controlled S. halepense. Despite the herbicide injury, hemp recovered and succeeded in higher biomass in both experiments at Thessaloniki and in higher seed production in the 2023 Thessaloniki experiment. This study showed that pendimethalin, s-metolachlor and aclonifen can be regarded as potential pre-emergence options with precautions in wet and light soils.

Hemp (Cannabis sativa L.) is a rapidly growing plant with multipurpose uses, and the optimal combination of yield and quality of hemp products (fibers, inflorescences, or seeds) may provide economic opportunities to uncover the full spectrum of its capabilities. The presented experimentation took place over seven years (2017–2023) in Greek climatic conditions for fourteen (14) registered monoecious and dioecious varieties. It can be concluded that the production of biomass, fiber, and seed weight were different not only between varieties but also from year to year. Despite significant variation between harvest years in biomass yield, the extracted fiber was relatively constant. Moreover, not only the dioecious varieties but also the monecious varieties could be effectively grown for biomass production in Greece. Regarding fiber production, monoecious varieties had the highest yields, apart from the dioecious Kompolti variety, which was the most fiber-productive. Under the experimentation conditions, early flowering varieties were most suited for seed production, and the KC Dora variety produced the heavier seeds. Generally, the Futura 75 variety was one of the most productive varieties for biomass and seed weight, while the Bialobrzeskie variety produced the greatest amounts of fiber.