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Helichrysum amorginum Boiss. and Orph. constitutes a range-restricted, endemic species of Greece with known pharmaceutical potency. The current work presents the results of a targeted evaluation of the total phenolic content (TPC) of methanolic extracts of H. amorginum flower heads under cultivation conditions at three consecutive harvest stages in two separate cultivation locations across a period of two years (2018 and 2019). The harvested inflorescence tissue was assessed for TPC via the Folin–Ciocalteu method in three and four-year old H. amorginum individuals. Older plants, during the second evaluation year, generally showed higher flower TPC content throughout. The pooled analysis of the results indicated significant differences in TPC among samples of extracts prepared with plant material from different harvest stages with the early flowering stage (A) presenting higher TPC in both experimental cultivation locations (142.6-156 mg GAE g-1 extract on average among the two cultivation locations) followed by the full bloom stage (B) (139-145.7 mg GAE g-1 extract on average) and the late bloom or early post-anthesis stage (C) which showed the lowest TPC in all cases (130.3-131 mg GAE g-1 extract on average). The current results provide for the first-time basic information on the optimum inflorescence harvest stage during the prolonged flowering period of cultivated H. amorginum in terms of TPC. The proposed work can be incorporated into the establishment of a sustainable cultivation protocol for achieving polyphenol-rich extracts and ultimately contributes to the utilization of H. amorginum in the pharmaceutical/cosmetic sectors.

Native phytogenetic resources can offer valuable germplasm diversity with potential for sustainable utilization. Helichrysum amorginum Boiss. and Orph. (Asteraceae) a Greek endemic, range-restricted neglected and underutilized plant species (NUP) holds significant utilization potential stemming from its known biochemical properties. The current study presents the results of a three-year experimental cultivation scheme of documented Greek H. amorginum germplasm aiming at its sustainable exploitation. Different planting densities in combination with ascending levels of organic fertilization in two distinct experimental fields were applied and plant growth coupled with inflorescence emergence and biomass yield were evaluated across a period of three years. The results highlighted the growth enhancing effect of organic fertilization under different planting densities with lower densities presenting a trend to sustain larger plants in terms of increased plant base diameter. Inflorescence emergence increased significantly from the second cultivation year onwards in both experimental fields with increasing levels of organic fertilization delivering higher rates of inflorescence number under decreasing planting densities. The current study provides a basis for a systematized research scheme that can facilitate further domestication and upscaling efforts leading to the sustainable utilization of H. amorginum in the pharmaceutical and cosmetics sectors, offering at the same time, local economic development.

Horseweed (C. canadensis) and fleabane (C. sumatrensis) are two annual or perennial herbaceous weeds present with high frequency and density in many parts of the world. Their response to water deficit was studied by means of seed germination tests and pot experiments. Seed germination was tested in solutions with different concentrations of polyethylene glycol (PEG). Two biotypes of each species were examined, one glyphosate resistant and the other susceptible. Growth responses were similar in the two species, both being more affected by lower (−1 MPa) than higher water potential (−0.2 MPa). The results revealed a significant effect of the biotype and the weed species on the drought stress response and adaptation. When high PEG concentrations were applied (−0.6 MPa), both C. sumatrensis biotypes had higher germination percentages (up to 88%) than the C. canadensis biotypes, while in most cases the seeds of the resistant biotypes germinated more (up to 72%) compared to the susceptible ones. These findings were confirmed by means of NDVI values, indicating that remote sensing can be used for a quick evaluation of the drought stress response of these weeds. The results obtained highlight the significant effect of species, biotypes and drought stress level on the germination, survival and growth of the weeds.

The use of earthworms in bio-composting (vermicomposting) is gaining popularity as a bio-waste management approach for producing nutrient-rich organic fertilizer. Furthermore, the use of seaweed extracts as biostimulants changes the physical, biochemical, and biological aspects of the soil, as well as the architecture of plant roots, allowing for more effective nutrient uptake and increasing plant development and yields. This study aimed to evaluate the combined effect of biocompost and biostimulant on the development of the root system of cannabis (Cannabis sativa L.) plant. An outdoor pot experiment was set up a completely randomized design, with four treatments including vermicompost, vermicompost amended with seaweed-based biostimulant, vermicompost mixed with spent mushroom substrate (SMS) and cattle manure (CM) compost, and vermicompost mixed with SMS+CM compost and amended with seaweed-based biostimulant. The results revealed that the highest values of root length density, root diameter, and nitrogen content in roots (1.36 cm cm-3, 1.29 mm, and 1.23%, respectively) were found in plants grown in the substrate of vermicompost mixed with SMS+CM compost and amended with seaweed-based biostimulant, pointed this out as a recommended treatment for increased biomass production, which is important in the processing of cannabis for medicinal purposes.

In hemp (Cannabis sativa L.) cultivation, an important management factor is apical cut (topping) as this modulates plant architecture, plant biomass allocation as well as the yield of inflorescences and cannabinoids per plant and area. This study aimed to evaluate the effect of topping treatment on agronomical and quality characteristics of two monoecious hemp varieties, ‘Fedora 17’ and ‘Felina’, A greenhouse pot experiment was laid out in a completely randomized design (CRD), with two topping treatments (untreated and topped). The results revealed that plant height of both varieties was negatively affected by topping treatment and the higher values were recorded in the untreated (137.02 and 134.56 cm for Fedora 17 and Felina, respectively). The highest values of dry weight per plant and bud dry weight per plant were noticed for topped plants. In conclusion, the findings of the present study implied that the hemp had a positive response to applied topping for all studied cultivars and the CBD content was higher in topped plants as topping stress increased cannabidiol (CBD) content.

A greenhouse pot experiment was conducted in the Agricultural University of Athens in order to evaluate the effect of several greenhouse cover materials on the performance and yield of hemp. The experiment was set up in a completely randomized design (CRD) with five treatments/greenhouses (G1, G2, G3, G4/Control, and G5). Measurements included plant height, PAR (Photosynthetic Active Radiation), chlorophyll content, solar irradiance, soil and leaf temperature, and yield components (the number of buds, their weight, length, and compact index, CBD content, and CBD yield per plant). The results of the present study suggest that the different polyethylene cover films alter the environment within the greenhouse and thus, affect the agronomic characteristics and yield traits of hemp. G1 reported the best results as it increased soil temperature and PAR values by 11-16% and 50-110% respectively, compared to G4. Concurrently, the majority of the bud characteristics were significantly improved in G1. Even though further research should be conducted in order to define the most suitable films for greenhouse hemp production, our results indicate that the optical properties of the greenhouse cover materials affect its yield and should always be considered.

A field experiment was conducted in the Agricultural University of Athens in order to evaluate the effect of different greenhouse cover materials on the CBD yield. Cannabis (Cannabis sativa L var. Futura 75) plants were grown in three different greenhouses, each constructed with different polyethylene films by PLASTIKA KRITIS S.A. The overall CBD yield per greenhouse was estimated once the cannabis buds matured. Following this evaluation, a business plan was formed for the greenhouse whose cover materials prompted the highest CBD yield. Out of the three greenhouses (GH1, GH2, and GH3), the highest CBD yield was reported on GH2. Two different cover materials, with different properties, were used for the construction of GH2, EVO 7507 AC and EVO 7526 AC. The results indicate that in a five-year span, cannabis production in greenhouses built with the aforementioned materials, could result in a Net Profit of more than 25.000.000 € ha-1. In conclusion, greenhouse cover materials should always be considered in cannabis greenhouse production. Even though greenhouse cannabis production for CBD oil seems to be a potentially profitable business in Greece, selecting appropriate cover materials can significantly increase producer’s profit.

Even though Delta-9-tetrahydrocannabinol (THC) is a psychoactive substance, studies indicate that it has therapeutic properties. Moreover, the modification in Greece legislation regarding the legalization of cannabis has resulted in new business opportunities for medical-cannabis related companies. This study aimed to evaluate whether different greenhouse cover materials affect THC yield and propose a business plan for any potential medical-cannabis related company in Greece. A greenhouse experiment was conducted in order to evaluate the effect of different plastic cover films in greenhouses for the cultivation of Cannabis sativa. Furthermore, the economic viability of a potential medical-cannabis related business in Greece was evaluated based upon a financial analysis. Yields were increased in greenhouses with double plastic cover materials (compared to the control). According to the results of our comparative economic analysis the production of medical cannabis in greenhouses constructed with double layered cover materials would significantly increase profits. Finally, greenhouse medical-cannabis production is much promising in Greece. Nevertheless, the use of appropriate greenhouse cover materials should be considered as they affect THC yield and therefore, the profit of the company.

The industrial hemp market is rapidly expanding, and best crop practices need to be assessed. This study aimed to determine the effect of fertilization and weed management on hemp crops and weed flora during the 2019 and 2020 growing seasons. Field experiments were laid out in a split–split plot design with three replicates: two hemp cultivars as main plots, three fertilization treatments as sub-plots, and three sub-sub-plots (weedy, weed-free, and herbicide application). For the computation of crop traits, 10 plants were randomly selected by each plot. Weed species were collected by quadrate for density and biomass weight determination. Increased fertilization rate positively affected plant height and dry biomass, while no impact was recorded on yield and yield components. The density and biomass of nitrophilous weeds were enhanced by fertilization, negatively affecting hemp growth. Marked differences were recorded on the competitive ability of cultivars since “Fedora 17” decreased the weed studied traits better than “Uso 31”. Herbicide application decreased the biomass of annual and perennial weeds by 38% and 13%, respectively, while it caused a reduction in hemp growth and yield of “Uso 31” plants. Further research should be conducted to address hemp yield losses under different cultural practices and weed control systems.

Allelopathic effects of various plants can be exploited for use against weeds; however, the selectivity in different crops is also important. In the current study, the effects of lemon balm (Melissa officinalis) allelochemicals on seed germination and seedling emergence of three biomass crops and three legume species were evaluated. Seed germination of rapeseed was reduced by 19, 30, 56, and 80% in the concentrations of 1, 2, 5 and 10%, respectively, as compared to the control group, whereas sweet sorghum seeds showed a more intermediate response and sunflower germination was affected only by the highest concentration. Seed germination of common bean was by 25, 34 and 60% lower at 1, 2 and 5% extract concentrations, respectively, in comparison to the control whereas up to 85% reduction of seed germination was recorded in 10% concentration. Peanut seed germination percentage ranged between 72 and 47% of control in 5 and 10% concentrations, respectively, while soybean germination was least affected from M. officinalis leaf extracts since it was reduced by only 25 and 41% in 5 and 10% concentrations, respectively, as compared to the control. Seedling emergence of rapeseed was reduced by 14, 25, 46, and 79% in the concentrations of 1, 2, 5 and 10%, respectively, as compared to the control whereas lemon balm extracts showed increased selectivity on the sunflower. Soybean emergence was reduced by only 27 and 46% in 5 and 10% concentrations, respectively, in comparison to the control whereas common bean’s seedling emergence was reduced up to 35% even in 2% concentration. Allelopathic response index values confirmed that sunflower and rapeseed were the least and most sensitive biomass crops to lemon balm allelochemicals, respectively, whereas sweet sorghum showed an intermediate response. Increased was the selectivity of the aqueous leaf extracts on soybean, whereas seed germination and seedling emergence of peanut were more affected and common bean was the most sensitive crop. Further research is needed to investigate the selectivity of M. officinalis and other aromatic plants’ allelochemicals on various crops and under different soil and climatic conditions to optimize their efficacy as tools of more eco-friendly weed management strategies.

Hemp is known to have a competitive advantage over weeds. Despite its suppressive ability, weed infestation remains an important issue during the early growth of the crop. The aim of this study was to determine the effect of fertilization and weed management on weed flora and hemp growth parameters during initial growth in the 2019 season. The experiment was laid out in a split-split plot design with three replicates: three hemp cultivars as main plots, three fertilization treatments as sub-plots and two sub-sub-plots (weedy, weed free). For the computation of height and biomass weight, 10 plants were randomly selected in each plot. Weed species were collected by quadrate and density and biomass weight were determined. ANOVA revealed that all factors and their interactions significantly affected plant traits. Hemp cultivars showed different competitive ability. ‘Futura 17’ reduced weed measurement traits better than ‘Uso 31’. Density and biomass of nitrophilous weeds increased with the higher N dose compared to control (up to 56% and 79% respectively), therefore negatively affecting the growth of the hemp plants. Further research is needed in order to identify useful information on interactions between weeds and hemp crop to address potential yield losses under different weed management systems.

Faba bean is an important grain legume, grown for human consumption and animal feed and can be used as an alternative to soybean protein. Drought and heat strongly influence faba bean growth and production, especially in flowering and pod development stages. The aim of this study was to determine the response of six cultivars to different environmental conditions during the 2018-2019 growing season. Four inbred lines and two commercial cultivars were sown in different environments in South, Central and North Greece. At each location, a randomized complete block design with four replications was used. Different characteristics such as plant height, number of pods plant-1, number of seeds pod-1, seed yield and 1000-seed weight, were recorded. The results indicated that all traits were significantly affected by different climatic conditions and cultivars. In most cases, seed yield and 1000-seed weight decreased with increasing drought conditions in the southern site. KK10 produced higher yield and pods plant-1, especially in North and Central Greece. The late maturity cultivars, ‘Polycarpe’ and KK14, showed lower values for the seed traits under all locations. Multi-location trials are useful for the evaluation of new cultivars and lead to an increase in production of feedstuff directly available to farmers.

Water availability is one of the major limiting factors of cotton productivity. The soil application of superabsorbent polymers (SAPs) may increase water use efficiency, improve soil physical properties, enhance seed germination and emergence, crop growth and yield and reduce the irrigation requirements of plants. The objective of this study was to investigate the effect of Zeba®, a polymer based on corn starch, on seedling emergence and growth of cotton under water stress. A set of pot experiments was conducted under completely randomized design with four replications of 25 seeds. Treatments included application rates of 5, 10, 15, 20 kg/ha and an untreated control, all under three levels of irrigation (adequate, moderate and deficit). The emergence performance was evaluated by final emergence percentage and mean emergence time. Root and shoot growth were measured for length and weight. The application of Zeba® promoted seedling emergence (higher emergence percentage from 17.9 to 22.6% and lower mean emergence time from 36 to 46% compared to control). Higher values for root and shoot traits were observed under Z10 and Z15 rates regardless of irrigation treatments. The adoption of the proposed SAP could represent a promising solution and thus increase moisture conservation in cotton.

In recent years, cannabis has raised public awareness in many countries worldwide about its medical uses. The European cannabis market reached its peak during 2018 with investments of 500 million €. Greece introduced Law 4523/2018, which regulates the production and processing of medical cannabis. A start-up business plan was drawn up for a medical cannabis operation owned a 1 ha greenhouse to estimate the start-up costs and the costs of cultivating and processing medical cannabis under greenhouse conditions in Greece. The results of the present study revealed that the investment was estimated at 4,960,044 €. Net profit in the first year amounted to 3,584,621.70 €, while the annual net profits from the second to the tenth year amounted to approximately 7.07 billion. The Net Present Value with a value of 45,425,241.24 € is positive and the internal rate of return (IRR) is 94.14%, which means that the investment can be characterized as profitable.

Helichrysum amorginum is a perennial shrub, endemic on the Greek island of Amorgos and used for medicinal, cosmetic and ornamental purposes. Information concerning germination behavior and seedling survival is considered essential for the establishment and cultivation of wild species. The objective of this study was to investigate the effect of temperature and light on germination of Helichrysum amorginum seeds. A set of experiments was conducted under completely randomized design with four replications of 200 seeds at three different suboptimal germination temperatures (15, 20 and 25°C) in light and dark conditions for 10 days. Seed material was collected from two different fields of the island (Aegiali and Katapola). The germination performance was evaluated by final germination percentage and mean germination time. The effect of temperature on seed germination percentage and mean germination time was significant in all cases. The presence of light enhanced germination, especially at the optimum temperature of 20°C. In most cases the mean germination time increased at the lower temperature of 15°C. Seeds from Aegiali exhibited higher germination ability than the seed lot from Katapola. Knowledge of seed germination behaviour is of major importance in order to establish effective protocols for seed propagation in Helichrysum amorginum.

Teff is an annual grass originated in Ethiopia, grown for both human food and animal feed. Salinity and moisture stress are the main limiting factors of agricultural development on arid and semi-arid regions. The aim of this study was to investigate the effect of salinity due to NaCl on germination of teff. A set of experiments was conducted under a completely randomized design with four replications of 200 seeds at two different suboptimal germination temperatures (15 and 25 °C) in the dark for 10 days. In order to create salt stress conditions during the germination process, seven solutions were used (0 as control, 80, 160, 240 and 320, 400 and 480 mM NaCl). The germination performance was evaluated by final germination percentage and mean germination time. The presence of NaCl reduced germination, especially above 240 mM for 15 °C and 400 mM for 25 °C. The mean germination time increased with higher NaCl levels.

A field experiment was conducted to evaluate the effects of biocyclic humus soil, a newly found apparently carbon stabilized form of organic matter with significantly different characteristics from common composts or other forms of organic matter (humus), on yield and quality of processing tomato. The experiment was laid out in a completely randomized design with three replications and three fertilization treatments (untreated, inorganic fertilizer and biocyclic humus soil). The highest fruit yield (116.8 t/ha) was obtained by using biocyclic humus soil. There were no treatment effects on fruit firmness (4.34-4.60 kg/cm2), total soluble solids (4.29-4.76 °Brix) and total acidity (0.25-0.31 g citric acid/100 g fruit) content of fruits. In conclusion, the tomato plants grown in biocyclic humus soil had 45% more yield than in conventional plots, and this big difference is probably related to the fact that the humus soil as a substrate provides an optimum environment for plant growth.

Soybean is considered to be an alternative crop and its cultivation could offer an innovative and high-quality product. A case study was implemented on an existing farm to examine the prospects of soybean production in Greece and to evaluate the economic outcomes of the crop cultivation under organic and conventional cropping system. The economic analysis showed that the cost of conventional soybean production was 0.37 €/kg, while the cost of organic soybeans was 0.50 €/kg. The organic and conventional soybean selling prices were 0.6 and 0.4 €/kg, respectively. In addition, the financial performance of the farm improved after the introduction of organic soybean crop, where the net profit increased by 26.3% compared to the initial profit of the farm, while the increase in the conventional was less at 10%. Soybean is a relatively new crop in Greece with high net profit, especially under organic cultivation mainly due to lower inflow of external imports.

A pot experiment was conducted to evaluate the allelopathic potential of Nigella sativa L. on seedling emergence and first growth of the serious weed rigid ryegrass (Lolium rigidum L.). The results revealed significant weed suppressive effects of N. sativa residues incorporated into the soil. The lowest seedling emergence rate (38%) was observed in pots treated with 20 g leaf residues. Regarding height, the lowest value (26.7 cm) was found in 20 g root residues. The highest quantity of shoot residues reduced leaf number, tiller number, fresh and dry aerial biomass up to 58, 51, 64 and 59%, respectively. It can be concluded that the effect of incorporation of plant residues depended on the type and amount of residue. N. sativa could be utilized as an allelopathic crop to control weeds and future studies should focus on isolating and identifying allelochemicals in roots, shoots and leaves of this species.

Vicia sativa L. (common vetch) is an annual legume species of high economic and ecological importance which is characterized by high nutritive value for animal feeding and its ability to adapt to various edaphic–climatic conditions. However, limited information is available about genotypic and environmental effects on agronomic, nutritional, and antinutritional traits of common vetch genotypes. Thus, in the present study, four advanced breeding lines and three commercial cultivars were evaluated for yield biomass, color assessment, fiber, crude protein (CP), and polyphenols in three locations (Spata, Larissa, and Thessaloniki) for two consecutive growing seasons (2018–2019 and 2019–2020). The effects of genotype, environment and their interaction (GXE) were significant for all the studied traits. The main source of variation for yield, color, CP, and polyphenols was the environment as it explained 71.5–89.7% of the total variation, whereas for the fibers content it was the GXE interaction. On the other hand, genotype had a much smaller effect on all the traits studied (2.9–16.6%). According to GGE biplot analysis, the ‘Alexandros’ cultivar was the most high-yielding and stable, whereas ‘Leonidas’ was the best performing in terms of nutritional and antinutritional traits. However, one advanced line combined high and stable yield biomass with high nutritive value, indicating the possibility for simultaneous improvement of both features.

In the field of Agricultural University of Athens, the effects of false seedbed technique, stale seedbed, chemical and ecologically based control on weed growth and soybean yield were evaluated (2019). The experimental treatments were: normal seedbed, normal seedbed along with pre-emergence chemical control, false seedbed, stale seedbed with glyphosate and stale seedbed with pelargonic acid. In the plots of normal seedbed along with pre-emergence chemical control, pendimethalin was applied at rate of 1560 g a.i. ha-1. In the plots of stale seedbed with glyphosate, glyphosate was applied at a rate of 2160 g a.e. ha-1 and in the plots of stale seedbed with pelargonic acid, pelargonic acid was applied at a rate of 31020 g a.i. ha-1. The experiment was conducted in a randomized complete block design with three replicates. The results revealed that stale seedbed combined either with glyphosate or pelargonic acid application reduced annual weeds’ density by 94 and 95% as compared to normal seedbed. Stale seedbed along with pelargonic acid reduced the density of perennial weeds by 36, 38 and 41% as compared to the combination of normal seedbed and pre-emergence chemical control, normal seedbed and false seedbed, respectively. The application of glyphosate in stale seedbed plots was also effective against perennial weeds. It was also observed that stale seedbed along with glyphosate increased soybean seed yield by 17, 19 and 35% as compared to the combination of normal seedbed and pendimethalin application, false seedbed and normal seedbed, respectively. Beneficial were also the effects of the combination of stale seedbed and pelargonic acid not only on soybean seed yield but also on soybean protein content. Further research is needed in order to investigate the role of false and stale seedbeds as integrated weed management practices in various crops and under different soil and climatic conditions. Research is also needed to evaluate pelargonic acid for weed control in stale seedbeds since it is an eco-friendly herbicide with no restrictions for organic farming.

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.

Lignocellulosic biomass is one of the dominant renewable energy resources suited for the production of sustainable biofuels and other energy purposes. This study was focused on weed management strategies that can improve the establishment of six lignocellulosic crops. The studied crops included: giant miscanthus, switchgrass, giant reed, cardoon, sweet sorghum, and kenaf. Delayed planting, increased planting densities, and mulching techniques can suppress weeds in giant miscanthus. Weed competition is detrimental for switchgrass establishment. Seedbed preparation and cultivar selection can determine its ability to compete with weeds. Giant reed is unlikely to get outcompeted by weeds, and any weed control operation is required only for the first growing season. Competitive cultivars and increased seeding rates maximize the competitiveness of cardoon against weeds. Several cultural practices can be used for non-chemical weed management in sweet sorghum and kenaf. For all crops, pre-emergence herbicides can be applied. The available safe post-emergence herbicides are limited. Mechanical weed control during crucial growth stages can provide solutions for sweet sorghum, kenaf, and perennial grasses. Further research is required to develop effective weed management strategies, with emphasis on cultural practices, that can improve the establishment of these prominent lignocellulosic crops.

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).

Sesame is one of the most important oilseed crops in the world. Irrigation is of great importance to sesame production due to its positive effect on growth parameters. Although sesame has good drought tolerance compared with many other crops, it is particularly susceptible to drought damage during the seedling, flowering and seed filling stages and this can lead to yield loss. The aim of this study was to determine the response of sesame landraces to different irrigation applications during the 2015 growing season. The experiment was set up as a split plot design with three replicates, four main plots (irrigation treatments, designated as 100%, 75% 50% and 0 of the daily crop evapotranspiration) and two sub-plots (sesame landraces, Limnos and Evros). Different characteristics such as plant height, number of seeds per capsule, and number of capsules per plant, seed yield, 1000-seed weight and % capsules without seeds, were recorded. The results indicated that all traits except 1000-seed weight were significantly affected by irrigation regimes. Plant height, shattering losses and number of capsules per plant decreased with increasing water shortage. Seed yield and number of seeds per capsule were less affected by irrigation level and showed higher values in the 50% of the daily crop evapotranspiration treatment. Limnos produced higher seed yield and number of seeds per capsule under all irrigation regimes. Evros showed higher plant height and shattering losses than Limnos. The results of this study suggest that sesame landraces can use water efficiently, are locally adapted and associated with traditional farming systems.

In Greece common marigold is one of the major medicinal plants widely used in cosmetics, perfumes and the pharmaceutical industry. A field experiment was conducted at Komotini, Greece, to compare the effect of organic and conventional fertilization combined with arbuscular mycorrhizal fungi inoculation on yield and floral qualitative characteristics of the common marigold during the 2015 growing season. The experiment was set up as a split plot design with three replicates, three main plots (fertilization treatments, inorganic, organic and untreated) and two sub-plots (addition/non-addition of commercial mycorrhiza of the genus Glomus spp.). Floral fresh and dry weight as well as total phenolic and flavonoid content of the dried flowers were recorded. Data analysis confirmed no significant correlation between fresh/dry floral yield, total phenolic and flavonoid content of the dried flowers and type of fertilization. The results also demonstrate a tendency of increase of the fresh or dry weight of the flowers when the commercial mycorrhiza is applied but it is not statistically significant.

There is growing consideration among farmers and researchers regarding the development of natural herbicides providing sufficient levels of weed control. The aim of the present study was to compare the efficacy of four different pelargonic acid products, three essential oils and two natural products’ mixtures against L. rigidum Gaud., A. sterilis L. and G. aparine L. Regarding grass weeds, it was noticed at 7 days after treatment that PA3 treatment (pelargonic acid 3.102% w/v + maleic hydrazide 0.459% w/v) was the least efficient treatment against L. rigidum and A. sterilis. The mixture of lemongrass oil and pelargonic acid resulted in 77% lower dry weight for L. rigidum in comparison to the control. Biomass reduction reached the level of 90% as compared to the control in the case of manuka oil and the efficacy of manuka oil and pelargonic acid mixture was similar. For sterile oat, weed biomass was recorded between 31% and 33% of the control for lemongrass oil, pine oil, PA1 (pelargonic acid 18.67% + maleic hydrazide 3%) and PA4 (pelargonic acid 18.67%) treatments. In addition, the mixture of manuka oil and pelargonic acid reduced weed biomass by 96% as compared to the control. Regarding the broadleaf species G. aparine, PA4 and PA1 treatments provided a 96–97% dry weight reduction compared to the corresponding value recorded for the untreated plants. PA2 (pelargonic acid 50% w/v) treatment and the mixture of manuka oil and pelargonic acid completely eliminated cleaver plants. The observations made for weed dry weight on the species level were similar to those made regarding plant height values recorded for each species. Further research is needed to study more natural substances and optimize the use of natural herbicides as well as natural herbicides’ mixtures in weed management strategies under different soil and climatic conditions.

E. colona is a C4 annual summer grass which is troublesome to major summer annual and perennial crops. Due to recent complaints by the farmers, the objectives of the present study were to evaluate the efficacy of penoxsulam, profoxydim, cycloxydim, cyhalofop-butyl, florpyrauxifen-benzyl and glyphosate against six E. colona accessions, and also to evaluate the response of these accessions to different rates of glyphosate in a dose-response experiment. In the first experiment, herbicides were applied at their maximum recommended label rates, while in the dose-response experiment, glyphosate was applied at six doses corresponding to 0, 1/4X, 1/2X, X, 2X, and 4X of the recommended rate. The dry weight of the biotypes TH8 and TH7 treated with profoxydim was 66% and 68% of the untreated control, respectively. The efficacy of cyhalofop-butyl against three accessions was lower than 30%, while two accessions were susceptible to this herbicide. The efficacy of penoxsulam against the biotypes ET2 and ET4 was lower than 10%, while dry weight of FT5 and TH8 was only reduced by 23%–28% as compared to the control. Cycloxydim application provided control higher than 75% at 21 days after treatment (DAT) of three accessions, while the majority of E. colona accessions was adequately controlled by the application of florpyrauxifen-benzyl. The response of the different accessions to glyphosate varied. The results of the glyphosate dose-response experiment revealed that the GR50 values of the resistant E. colona accessions ET2 and ET4 were up to 1098 and 1220 g a.e. ha−1 of glyphosate, respectively, whereas the GR50 value of the susceptible accession (FT5) was only 98 g a.e. ha−1. The resistance indices of ET2 and ET4 were 12.4 and 11.2, respectively, indicating that they have already developed resistance to glyphosate. Three more accessions could be also of developing resistant to glyphosate. This is the first report of glyphosate resistance from E. colona accessions in Greece, with indications of multiple resistance also present. Further research is needed in order to evaluate the efficacy of several herbicides under different soil and climatic conditions, conduct baseline sensitivity studies, reveal the evolvement of resistance patterns to glyphosate from accessions of Echinochloa spp., and search for alternative options of weed management in annual and perennial crops due to the clear indications of multiple resistance situations.

A field experiment was conducted at Pylos, Greece to compare the effect of different types of fertilization on yardlong bean (Vigna unguiculata subsp. sesquipedalis) crop. The conventional treatment plots were fertilized with an inorganic fertilizer, whereas the organic treatments plots received organic compost. Data analysis confirmed no significant correlation between plant height and type of fertilization, but there was significant correlation between length of pods and type of fertilization. In particular, morphological characteristics of yardlong bean were enhanced by inorganic fertilization in comparison with the organic fertilization. Organic farming increased significantly the number on root nodules in comparison with conventional farming.

The use of magnetic field as a presowing treatment has been adopted by researchers as a new environmental friendly technique. The aim of this study was to determine the effect of magnetic field exposure on tomato seeds covering a range of parameters such as transplanting percentage, plant height, shoot diameter, number of leaves per plant, fresh weight, dry weight, number of flowers, yield, and lycopene content. Pulsed electromagnetic field was used for 0, 5, 10, and 15 minutes as a presowing treatment of tomato seeds in a field experiment for two years. Papimi device (amplitude on the order of 12.5 mT) has been used. The use of pulsed electromagnetic field as a presowing treatment was found to enhance plant growth in tomato plants at certain duration of exposure. Magnetic field treatments and especially the exposure of 10 and 15 minutes gave the best results in all measurements, except plant height and lycopene content. Yield per plant was higher in magnetic field treatments, compared to control. MF-15 treatment yield was 80.93% higher than control treatment. Lycopene content was higher in magnetic field treatments, although values showed no statistically significant differences.