RESUMEN
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.
RESUMEN
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).
RESUMEN
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.
RESUMEN
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).
