Search Results (6)

In Europe, industrial hemp (Cannabis sativa L.) is currently cultivated primarily for its fibers and seeds due to regulatory restrictions on flower use, although the flowers present untapped valorization potential. This study assesses the economic viability of cultivating hemp for its inflorescences and examines the quality impact of different cultivation methods by testing two varieties, Santhica 27 and Félina 32, across distinct growth environments. The cultivation systems tested include greenhouse-based soilless setup and open-field production. Within the greenhouse, the effects of an ethylene-based growth regulator, applied during the vegetative stage, on plant morphology and cannabinoid concentrations were assessed at three dosage levels (7.5, 15, and 30 µL L⁻¹). The results showed a dose-dependent reduction in shoot height, lasting 21 to 28 days post-treatment before diminishing. Comparable total cannabigerol (CBG) levels were achieved with Santhica 27 in both field conditions and at the 30 µL L⁻¹ ethylene dose in the greenhouse, while total cannabidiol (CBD) levels in Félina 32 were higher in the field than in the greenhouse. Overall, greenhouse cultivation yielded significantly greater cannabinoid production per square meter due to increased inflorescence biomass and the potential for multiple harvest cycles. However, operating costs for greenhouse cultivation are at least 13 to 15 times higher than those of open-field production. Economic analysis suggests that optimizing greenhouse cultivation techniques and reducing labor requirements at harvest could help mitigate these costs, enhancing the economic feasibility of greenhouse-based hemp flower production. Full article

Hybrid Bermuda grasses (Cynodon dactylon × C. transvaalensis Burtt.-Davy) represent one of the greatest contributions to the growing quality of turfgrass in the warm season and transition zone areas of the world. Hybrid Bermuda grass production relies on vegetative propagation from sod or sprigs. In the past, efforts have focused on improving the technique of stolonizing (or sprigging) for establishment in new areas. Such propagation requires bulk harvesting and planting of all rhizomes and stolons. We have developed a novel method of propagation and establishment from a single node harvested from greenhouse grown stolons. Despite a stolon fraction bearing a single node being suitable for effectively propagating a warm-season turfgrass, the technique has been held as economically impractical until now. Our method has been developed to obtain the multiplication of plant material in soilless conditions by harvesting single-node sprigs, propagation of plants from the single nodes, and transplant of single plants in the field. The investigation aimed to identify values for method set-up. Indeed, node and internode size variability with differential between maximum diameters is crucial for discrimination. For Patriot Bermuda grass stolons, nodes exhibited a maximum diameter of 2.43 ± 0.46 mm, while internodes had a maximum diameter of 1.54 ± 0.16 mm. Based on these findings, a 2 mm sieve was selected, achieving an optimal ratio between the node fraction and internode residues. The sieve yielded 87% of node fractions and only 1% of internodes from the initial mix, demonstrating its efficacy. Further results for the transplanting phase indicated that a double release resulted in an average success rate of 98.8%, with only 6.9% blank cells when using a single release. The average was 149 plants per tray over 160 cells, representing a 93.1% success rate. These results underscore the efficiency and acceptability of the overall propagation process in alignment with market references. Full article

Soilless cultivation represents a promising method for the future of the horticulture industry as it offers advantages such as improved quality control over the growth environment and mitigation of uncertainties related to soil, water, and nutrient availability. In this study, we aimed to investigate the effects of different environments, specifically greenhouse (GH) and open-field (OF), on the growth, phenotypic characteristics, physio-biochemical properties, qualitative parameters, and antioxidant capacity of strawberries cultivated using a soilless system. The aforementioned parameters were measured in both the GH and OF settings. Our findings revealed that the growth, yield, and morphological parameters were significantly higher in the GH environment compared to the OF. However, when considering fruit quality indices such as fruit texture firmness, fruit dry matter percentage, taste index (TSS/TA ratio), and post-harvest shelf-life, the OF cultivation method exhibited significantly superior results. Moreover, various aspects, related to plant physiology and biochemistry, antioxidant enzyme activity, total antioxidant capacity (DPPH), vitamin C content, and secondary metabolites, were found to be significantly higher in the OF environment compared to the GH. Overall, the results of our study suggest that OF soilless cultivation outperforms GH cultivation in terms of fruit quality, antioxidant capacity, and post-harvest shelf-life. Despite the observed decrease in fruit growth and yield, soilless strawberries grown in OF are likely to yield a final product of higher quality and nutritional value compared to those cultivated in a GH environment. These findings highlight the potential of OF soilless cultivation as a viable approach for strawberry production, emphasizing the importance of considering not only yield but also qualitative aspects and the nutritional value. Further exploration and optimization of soilless cultivation techniques in OF settings could contribute to the advancement of sustainable horticultural practices. Full article

Traditionally, biochar is generally proposed to substitute Canadian Sphagnum peat moss. Sugarcane bagasse, filter press mud and sugarcane bagasse ash were mixed in different ratios and proposed as an alternative to substitute commercial Sphagnum peat moss (SPM) for the soilless cultivation of tomato (S. lycopersicum Linnaeus). The choice of the agroindustrial waste ratio was performed from physical-chemical sample characterization. During vegetable production, an adequate ratio was evaluated based on plant height, substrate pH, number of leaves, yield, and fruit size. The addition of essential macro- and micro-nutrients was performed manually. The results show that as-received materials contain different minerals with a structure that corresponds to the quartz, cristobalite, and feldspar phases. A morphology composed of lamellate structures was observed for sugarcane bagasse, whereas the filter press mud and the sugarcane bagasse ash presented compact agglomerates with a surface area of 1.60, 3.78, and 1.07 m² g⁻¹, respectively. The properties of each component promote the water adsorption, retention and releasing capacity. Important differences were observed as the quantity of filter press mud increased, but also it is required an amount of sugarcane bagasse above of 18 wt% to reach a superior performance. This work demonstrated that, in adequate quantities, agroindustrial wastes can be used as a soilless substrate for growing tomatoes in greenhouse, reducing their disposal problems. Full article

Lettuce (Lactuca sativa L.) is a leading greenhouse-grown vegetable. However, nitrate (NO₃⁻) accumulation in leaves remains a major issue. The aims of this research were: (i) to test the modified intermittent Nutrient Film Technique (NFT) in the cultivation of soilless lettuce in which plants are grown on peat blocks in trays and supplied with an intermittent flow of nutrient solution, and (ii) to calibrate the fertilization scheme to increase yield performance, while keeping NO₃⁻ concentration under control. Two greenhouse trials were performed between autumn 2013 and spring 2014. Results showed that a 30-day cycle is the optimum duration in terms of fresh biomass yield, both for autumn and spring cultivation. Reducing N fertilization in the last cropping days never affected NO₃⁻ concentration in leaves during autumn trial, due to unfavourable growing conditions. Conversely, suspension of fertilization 2 days before harvest had a consistent effect during the spring trial, when NO₃⁻ concentration in leaves was highly reduced (from 20 to 36%) without yield penalties. Thus, suspending fertilization 2–4 days before harvesting in intermittent NFT may reduce, on average, NO₃⁻ accumulation by 29–58% and the fertilization rate by 7–16%, respectively. Yet, growing conditions are crucial to make this system effective. Full article

As the demand for high-quality wild greens rises, due to their high nutritional, culinary, and medicinal properties, the potential overexploitation and excessive disruption of their natural habitats bring serious environmental problems to the foreground. However, new alternative cultivation techniques, such as hydroponic cultivation, could take advantage of rational water management, optimal fertilization management and climate adaptation, to produce high-quality wild greens, all year round. As an initial step to assess optimal hydroponic cultivation conditions for golden thistle (Scolymus hispanicus L.), in this study we evaluated the effect of N:K ratio and electrical conductivity (EC) in the supplied nutrient solution on plant growth, yield and phenology. Four nutrient solutions were applied with a low or a high N:K ratio (1.59 or 2.38 mol/mol, respectively) combined with a low or a high electrical conductivity (EC) level (2.2 and 2.8 dS m⁻¹, respectively) in a 2 × 2 factorial experiment set as a completely randomized block design with 4 blocks and 48 plants per block. Golden thistle seedlings were planted in plastic growth-bags of hydroponic perlite substrate in an open, drip-irrigated, soilless cultivation system. The experiment commenced in December 2018, in a plastic greenhouse at the campus of the Hellenic Mediterranean University, Crete, Greece. After four months of cultivation, the post-harvest analysis showed that the high N:K ratio significantly increased the fresh weight of leaf and edible tuberous root, whereas the tested EC levels in the nutrient solution had no impact on plant fresh weight. The experimental treatments did not significantly affect leaf chlorophyll concentration (SPAD meter readings), chlorophyll fluorescence (Fv/Fm) or the number of leaves and the specific weight of the tuberous root of the plants. Our results indicate that wild golden thistle could be domesticated as an edible vegetable, and cultivated hydroponically at different seasons of the year using relatively low nutrient concentrations, thereby minimizing aquifer nitrate and phosphate pollution. A nutrient solution with a relatively high N:K ratio (here 2.38 mol/mol) is recommended for the hydroponic cultivation of golden thistle. Full article