Uncovering the metabolite complexity and variability of cultivated hemp (Cannabis sativa L.): A first phytochemical diversity mapping in Greece.

The high value of fiber-type Cannabis sativa L. (hemp) due to its phytochemicals has yet to be fully recognized and leveraged. Besides cannabidiol (CBD), which is the most prevalent non-psychoactive cannabinoid, hemp contains numerous other cannabinoids with unexplored bioactivities, in addition to various compound classes. Previous works have aimed to correlate chemical profiles of C. sativa inflorescences with important parameters, mostly based on experiments under controlled conditions. However, mapping studies that explore the phytochemical diversity of hemp in a more realistic context are crucial to guide decisions at multiple levels, especially in areas where hemp cultivation was recently re-authorized, including Mediterranean countries. In this work, a powerful strategy was followed to map the phytochemical diversity of cultivated hemp in Greece, being the first study of its kind for this environment. A panel of 98 inflorescence samples, covering two harvesting years, eleven geographical regions and seven commonly used EU varieties, were studied using a combination of targeted and untargeted approaches. Quantitative results based on UPLC-PDA revealed relatively constant CBD/THC (total) ratios, while profiling by LC-HRMS effectively probed the phytochemical variability of samples, and led to the annotation of 88 metabolites, including a multitude of minor cannabinoids. Multivariate analysis substantiated a strong effect of harvesting year in sample discrimination and related biomarkers were revealed, belonging to fatty acids and flavonoids. The effect of geographical region and, especially, variety on chemical variation patterns was more intricate to interpret. The results of this work are envisioned to enhance our understanding of the real-world phytochemical complexity of C. sativa (hemp), with a view to maximized utilization of hemp for the promotion of human well-being.

Alternative Crops for the European Tobacco Industry: A Systematic Review.

Tobacco (Nicotiana tabacum L.) is a major industrial crop that has being cultivated for centuries for the manufacturing of cigarettes, cigars, and other smoking products. Due to its negative effects on both human health and the environment, the European Union has adopted strict policies that aspire to reduce the consumption of tobacco. Herbal cigarettes are alternative smoking products that are often advertised as healthier than conventional tobacco cigarettes and are especially popular in Asian markets. Even though the available literature suggests that they are equally detrimental to human health, the introduction of tobacco-alternative crops (TACs) to the European tobacco industry could smoothen the abandonment of tobacco, and eventually smoking products altogether, in the EU. The aim of the present systematic review was to compile a list of possible TACs that could be incorporated in the European smoking industry, and highlight their strengths and weaknesses. The most dominant crops in the literature (and in the existing market products) were calendula (Calendula officinalis L.), mullein (Verbascum thapsus L.), ginseng (Panax ginseng C.A.Mey.), tea (Camellia sinensis (L.) Kuntze), chamomile (Matricaria chamomilla L.), and mentha (Mentha spp.). Even though these crops are promising, further research is required for their incorporation in the European tobacco industry.

Effect of Arbuscular Mycorrhizal Fungi on Nitrogen and Phosphorus Uptake Efficiency and Crop Productivity of Two-Rowed Barley under Different Crop Production Systems.

Arbuscular Mycorrhizal Fungi (AMF) constitute a ubiquitous group of soil microorganisms, affecting plant and soil microorganism growth. Various crop management practices can have a significant impact on the AM association. This study investigated the AMF inoculation contribution on growth and productivity of two-rowed barley crop by identifying the underlying mechanisms both in conventional and organic cropping systems. A two-year field trial was set up as a split-plot design with 2 main plots [AMF inoculation: with (AMF+) and without (AMF-)] and five sub-plots (fertilization regimes: untreated, 100% recommended dose of fertilizer in organic and inorganic form, and 60% recommended dose of fertilizer in organic and inorganic form) in three replications. According to the results, AMF+ plants presented higher plant height and leaf area index (LAI), resulting in increased biomass and, as a result, higher seed yield. With regard to the quality traits, including the nitrogen and phosphorus uptake and their utilization indices, the AMF inoculated plants showed higher values. Furthermore, the level of fertilization, particularly in an inorganic form, adversely affected AMF root colonization. Consequently, it was concluded that substitution of inorganic inputs by organic, as well as inputs reduction, when combined with AMF inoculation, can produce excellent results, thus making barley crop cultivation sustainable in Mediterranean climates.

On the Path towards a "Greener" EU: A Mini Review on Flax (Linum usitatissimum L.) as a Case Study.

Due to the pressures imposed by climate change, the European Union (EU) has been forced to design several initiatives (the Common Agricultural Policy, the European Green Deal, Farm to Fork) to tackle the climate crisis and ensure food security. Through these initiatives, the EU aspires to mitigate the adverse effects of the climate crisis and achieve collective prosperity for humans, animals, and the environment. The adoption or promotion of crops that would facilitate the attaining of these objectives is naturally of high importance. Flax (Linum usitatissimum L.) is a multipurpose crop with many applications in the industrial, health, and agri-food sectors. This crop is mainly grown for its fibers or its seed and has recently gained increasing attention. The literature suggests that flax can be grown in several parts of the EU, and potentially has a relatively low environmental impact. The aim of the present review is to: (i) briefly present the uses, needs, and utility of this crop and, (ii) assess its potential within the EU by taking into account the sustainability goals the EU has set via its current policies.

Herbicide Use in the Era of Farm to Fork: Strengths, Weaknesses, and Future Implications.

Climate change mitigation is a major concern of the European Union (EU). In 2019, the EU presented the European Green Deal (EGD), a new environmental strategy that aimed to neutralize climate change by 2050. Within its policy areas, the EGD included the Farm to Fork (F2F) Strategy that aims to reduce pesticide use by 50%, by 2030. This reduction was proposed due to the supposed negative effects of pesticides on the environment and its biota. Among the different pesticide groups (herbicides, fungicides, insecticides, etc.) though, herbicides are perhaps the hardest to reduce. This review aimed to shed light to any factors that might hinder the reduction of herbicide use; thus, the implementation of the Farm to Fork Strategy underlines some of its weaknesses and highlights key points of a viable herbicide reduction-related policy framework. The literature suggests that integrated weed management (IWM) consists perhaps the most suitable approach for the reduction of herbicides in the EU. Even though it is too soon to conclusively assess F2F, its success is not impossible.

The Role of Alternative Crops in an Upcoming Global Food Crisis: A Concise Review.

Achieving Food Security (FS) is perhaps our most challenging aspiration. Despite our best efforts, millions of people around the globe are malnourished or live with hunger. The state of the geo-political scene, as well as the COVID-19 pandemic, have recently brought forth fears of a Global Food Crisis (GFC). Here, we present the factors that threaten FS and could trigger a GFC, examine the potential of alternative crops (ACs) as a measure against an upcoming GFC, and highlight the key aspects of the ACs introduction process in new regions. ACs could enhance FS, yet their success is premised on the adoption of sustainable practices and the implementation of food strategies that aim to promote healthy consumer behaviours.

The Influence of Fertilization and Plant Density on the Dry Matter Yield and Quality of Black Mustard [Brassica nigra (L.) Koch]: An Alternative Forage Crop.

Black mustard [Brassica nigra (L.) Koch] is mainly cultivated as a seed crop, and there is a lack of information on biomass quality and its potential for animal feeding. A 2-year field experiment was set up in a split-plot design with 2 main plots (plant densities: 46 and 76 plants m-2), 4 sub-plots (fertilization levels: control, compost, urea with and without urease and nitrification inhibitors) and 3 replications for each treatment. The highest dry matter yield (17.55-18.34 tn ha-1) was observed in high-density plots fertilized with urea fertilizer coated with double (nitrification and urease) inhibitors. In terms of the qualitive parameters of total above-ground biomass, the highest crude protein (CP) content was achieved in plots with low density and urea with double inhibitors. Moreover, the highest neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of above-ground biomass were found under compost and urea with double inhibitors. The high ADF, NDF and relatively high CP content characterized that black mustard aerial biomass can meet the requirements of lactating animals, and therefore the production of black mustard biomass as a forage crop could be of great importance. As a conclusion, black mustard cultivated at plant densities higher than 46 plants m-2 and under inorganic fertilization, especially with urea coated with double inhibitors, could be successfully used as a novel forage crop in ruminants' diets.

Assessment of plant growth promoting bacteria strains on growth, yield and quality of sweet corn.

The use of plant growth promoting bacteria (PGPB) is increasingly gaining acceptance from all the stakeholders of the agricultural production. Different strains of PGPB species had been found to have a vast variety of mechanisms of action, while at the same time, affect differently a variety of crops. This study investigated the effectiveness of ten PGPB strains, on sweet corn cultivation under Mediterranean soil and climatic conditions. A field experiment that followed a completely randomized design was conducted at the region of Attica at Oropos. The results indicated that B. mojavensis increased yield by 16%, B. subtilis by 13.8%, B. pumilus by 11.8% and B. pseudomycoides by 9.8% compared to control. In addition, the harvested grains of the plants treated with B. mojavensis, B. subtilis and B. pumilus presented the highest values of protein and fiber content. Moreover, in most of the cases, high values of photosynthetic rate, transpiration rate and stomatal conductance during the cultivation period, resulted in high productivity. Regarding the texture, the size, the sphericity and the ash content of corn grains, it was found that they were not influenced by the application of different treatments of PGPB. The use of certain strains of PGPB, under specific soil and climatic conditions could contribute to better understand which strains are better suited to certain crops.

Evaluation of Plant Growth Promoting Bacteria Strains on Growth, Yield and Quality of Industrial Tomato.

Plant growth promoting bacteria (PGPB) are used as biostimulants to improve the growth and yield as well as the quality of crops. In the present study, nine strains of PGPB and one solid mix consisting of two of them were evaluated on the cultivation of industrial tomato under specific soil and climatic conditions. The results showed that Bacillus licheniformis treatment increased dry weight of the tomato plants by 39%, and the photosynthetic rate was increased by Priestia megaterium 9.9%. The application of Bacillus subtilis, Bacillus amyloliquefaciens, Priestia megaterium, and Bacillus licheniformis increased mean fruit weight per plant 26.78-30.70% compared to that of control. Yield per plant was increased 51.94% with the use of Bacillus licheniformis compared to that of control. The quality of the fruits in nearly every bacteria strain was improved. Bacillus pumilus and the mix of Priestia megaterium and Azotobacter chroococcum (1:1) increased the most total soluble solids in the tomato fruits (4.70° Brix), and Priestia megaterium increased content in lycopene and total carotenoids by 52.8% and 25%, respectively; Bacillus pseudomycoides increased Pectin methylesterase (PME) activity (24.94 units/mL), and Bacillusmojavensis, along with the mix of Priestia megaterium and Azotobacter chroococcum, increased Poligalacturonase (PG) activity the most (30.09 and 32.53 units/mL, respectively). Most of the bacteria strains presented an increased antioxidant activity significantly better that that of the control up to 31.25%. The results of this study confirmed that the use of PGPB as biostimulants can improve the yield and the quality of industrial tomato.

Reintroducing Flax (Linum usitatissimum L.) to the Mediterranean Basin: The Importance of Nitrogen Fertilization.

An increasing interest has been reported regarding the reintroduction of flax in the Mediterranean region. The aim of this present study was to evaluate the effects of nitrogen (N) fertilization on the performance of flax cv. Everest, under Mediterranean climate conditions. A two-year study was carried out in 2018-2019, in Western Greece. The experiment was set-up in a randomized complete block design with four replications and six treatments of different N fertilization rates (0, 20, 30, 40, 50, and 60 kg N ha-1). Measurements included plant biomass, the leaf area index (LAI), the yield, and the Growth Degree Days (GDDs) required for full seed maturity. The N uptake of flax was also evaluated utilizing the Nitrogen Harvesting (NHI) and Nitrogen Utilization Efficiency (NUtE) indices. Although the highest fertilization rate (60N) increased the yield by 35.4% (2018) and 23.1% (2019), a GDDs and N indices assessment revealed that it noted the lowest efficiency and may lead to significant yield losses, as it significantly prolonged the crop cycle. On the contrary, even though fertilization rates of 20 and 30 kg N ha-1 increased the yield only by 7% and 15% (on average), they were more efficient, and prolonged the crop cycle less (compared to 60N).

Effect of Rhizophagus irregularis on Growth and Quality of Cannabis sativa Seedlings.

Rhizophagus irregularis is an arbuscular mycorrhiza fungus that can enhance plant nutrition and reduce transplant shock on seedlings. The present study aims to evaluate the effects of this fungus on the quality of cannabis (Cannabis sativa L.) seedlings.A greenhouse float system experiment was conducted in a completely randomized design with three treatments. The treatments included the application of 40, 80 and 120 fungus spores per L of nutrient solution (AMF1, AMF2 and AMF3, respectively). The evaluation was performed based on the agronomic characteristics of the seedlings (root and stem length and weight, stem diameter), N and P content, survival rate, and the Dickson's quality index (DQI). Results indicated that root length and stem dry weight were significantly increased (by 34.14% and 21.4%, respectively) in the AMF3 treatment. The biomass of the seedlings' roots, the fresh weight and the N content were not affected by the AMF. On the contrary, survival rate, P content and DQI were significantly increased in AMF3 (by 5%, 24.3% and 12.4% respectively). Overall, our findings suggest that the application of high doses of Rhizophagus irregularis (AMF3) on float system-produced cannabis seedlings results in a considerable increment of their quality.

Effect of Colonization of Trichoderma harzianum on Growth Development and CBD Content of Hemp (Cannabis sativa L.).

Trichoderma harzianum, as a natural endophytic biocontrol agent, can ameliorate plant development, nutrient uptake, and resistance to biotic and abiotic stresses. This study aimed to investigate the effect of Trichoderma harzianum inoculation on agronomical and quality characteristics of two monoecious hemp (Cannabis sativa L.) varieties, Fedora 17 and Felina. A greenhouse pot experiment was conducted in a completely randomized design of two treatments of Trichoderma harzianum with a low and high dose of the fungus (T1 and T2). The significance of differences between treatments was estimated by using a Fisher's test with a significance level p = 0.05. The root density of both varieties was significantly affected by treatments, and higher values were recorded in Fedora 17 (2.32 mm cm-3). The Arbuscular Mycorrhizal Fungi (AMF) colonization of the root system and the soil emission of CO2 were higher after the inoculation of Trichoderma harzianum. The highest values of plant height and dry weight were noticed for T2, especially in variety Felina. Trichoderma harzianum positively influenced characteristics of inflorescences such as their number, fresh weight moisture, and compactness in both varieties, while the dry weight, length, and dry yield of inflorescences were not improved. Finally, the fertigation of Trichoderma harzianum in hemp plants was beneficial by increasing the cannabidiol (CBD) content, especially in T2 treatment (4 × 1012 CFU kg-1).