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).

Field experiments were conducted during 2019 in two different locations in Greece (Athens and Farsala) to evaluate the effect of urea and urea fertilization with inhibitors on the agronomic yield and quality characteristics of two cannabis varieties (Cannabis sativa L.), “Uso31”and “Fedora 17”. The experimental design was split-plot with four different fertilization treatments—control, Urea (U), urea with Urease Inhibitor (UI), and urea with Nitrification Inhibitor (NI) and urease inhibitor (UI). The significance of differences between treatments was estimated by using Tukey’s test with a significance level of p = 0.05. The plant height was significantly affected by the different fertilizations and different varieties as well as by the two locations. The maximum plant height was 197 cm for “Fedora 17”in Farsala. The seed yield was higher forthe urea with inhibitors treatment in both varieties. The Cannabidiol (CBD) content was significantly affected by the fertilization—it was higher in urea with inhibitors in “Uso31”and “Fedora 17” treatments. The lowest CBD content value was 1.29% (control) and the highest was 1.69% (urea NI + UI). In conclusion, in both varieties, it seems that urea with inhibitors has a positive effect on their growth, as well as on the increase in cannabidiol (CBD) content.

While processing tomato cultivation (Solanum lycopersicum L.) is considered one of the most important industrial crops in Greece, a waste known as tomato pomace is growing significantly high. Notably, the tomato pomace presents enormous opportunities for the creations of organic fertilizers. The aim of this study was to investigate the use of tomato pomace as a fertilizer in the same crop. A field experiment was established at the Agricultural University of Athens during 2018 and 2019 in a randomized complete design with five treatments (control, inorganic NPK (NPK), Tomato pomace and Biocycle Humus Soil (Tp and BHS), Tomato pomace and Farmyard manure (Tp and FYM), and Tomato pomace and Compost (Tp and CM). Physical soil properties such as soil porosity and penetration resistance were improved by the application of organic blends. Additionally, soil nitrogen content ranged from 0.10% (control and NPK) to 0.13% (Tp and FYM). A significant increase of yield was noticed under organic fertilization where the highest yield of 8.00 tn ha⁻¹ was recorded in Tp and BHS (2018). Lycopene content was significantly affected by fertilization and its highest values were 87.25 (Tp and BHS; 2018), and 88.82 mg kg⁻¹ fresh (Tp and FYM; 2019). Regarding fruit firmness, the three organic blends did not have statistically significant difference. In addition, the Total Soluble Solids (TSS) was significantly affected by the fertilization and the maximum value was 4.80 ◦Brix (Tp and CM; 2018). In brief, tomato pomace blended with organic fertilizers was yielded considerable since it improved soil quality and increased yield.

Four advanced tritordeum lines were studied and compared to two commercial varieties of tritordeum and wheat cultivars in yield and quality features, in Greece. For this purpose, a two-year experiment was established in the Greek territory. The field experiment was set up in Randomized Complete Block Design (RCBD) with blocks, with different lines and varieties. Head emergence was calculated based on Growing Degree Days (GDDs), which was significantly affected by the year. The significance of differences between treatments was estimated by using Fisher’s least significant difference (LSD) test with significance level p = 0.05. The weight of 1000 seeds of the two commercial varieties differed from the equivalent weight of 1000 seeds of tritordeum lines, approximately 1 g. Yield was significantly affected by lines/varieties and year. Compared to tritordeum yield, wheat yield marked the highest values. This difference was almost 2 kg ha⁻¹. Gluten content was significantly affected by lines/varieties. The highest gluten content was firstly noticed at wheat GENESIS (34.2%) variety and secondly at tritordeum Aucan (33.2%) variety. Protein was higher in tritordeum lines HT-1704 (15.5%), HT-1707 (15.1%) and Aucan variety (15.2%) during the first experimental year. Tritordeum seems to have significant adaptability to dry conditions in Greece and significant yields compared to the existing commercial varieties and bread wheat.

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).