Effect of Limited Drip Irrigation Regime on Yield and Yield Components of Sesame under Mediterranean Conditions

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.

Effect of Nitrogen Fertilization on Growth and Yield of Industrial Hemp (Cannabis sativa L.)

Fibre hemp is grown for a multitude of end products derived from its cannabinoids, seed, fibre and wooden core. A key factor that influences the quantity and quality of the production of hemp is nitrogen fertilization. The aim of this study was to determine the response of five well-adapted industrial hemp cultivars to different nitrogen fertilization rates during the 2016 growing season. The experiment was laid out in a split-plot design with two replicates, five main plots (hemp cultivars: ‘Bialobrzeskie’, ‘Tygra’, ‘Felina 32’, ‘Sanhtica 27’, ‘Futura 75’) and sub-plots [fertilization treatments: control (N0), fertilizer 46-0-0 at 120 kg ha-1 (N1), 180 kg ha-1 (N2), 240 kg ha-1 (N3)]. For the computation of height, biomass yield, stem dry weight, length and weight of the inflorescences and mean seed weight, 10 plants were randomly selected in each plot. In general, increasing N fertilization rate positively impacts hemp biomass yield, stem dry weight, plant height, and inflorescence indices. Biomass yield, stem dry weight and inflorescence weight increased by 37.3%, 48.2% and 16%, respectively, with the application of 240 kg N ha-1 when compared with the unfertilized control. Plant height and inflorescence length increased from 1.66 to 1.76 m and from 66.2 to 82.9 cm, respectively, with the application of the higher N rate compared with the control, while there were no significant differences between the fertilization treatments for mean seed weight. The varieties ‘Tygra’ and ‘Futura 75’ showed the highest values for all the measurement characters. Our results indicate that hemp responded well to the addition of N fertilizer

Seed priming effects on germination and first growth of the medicinal plant Achillea millefolium L.

This study evaluated the effects of seed priming on germination and growth of A. millefolium by means of laboratory and greenhouse experiments conducted during 2018 in the Agricultural University of Athens. Treatments were GA3 (400 and 800 ppm), potassium nitrate (2% and 4%), polyethylene-glycol (soaking for 12 and 24h) besides an untreated control. Experiment in Petri dishes revealed that GA3 at 400 ppm, potassium nitrate (at concentration 2 and 4%) and PEG significantly increased germination percentage of A. millefolium, while germination rate was also significantly improved as a result of all seed priming techniques. In addition, due to the soil experiment, seedling emergence was significantly increased by GA3 at 400 ppm, potassium nitrate (at both concentrations) and PEG compared with the untreated seeds. Dry biomass of the young seedlings was significantly enhanced by means of GA3 (at 400 and 800 ppm), KNO3 (4%) and PEG for 24 h, indicating the potential effect of seed priming on first growth as well. The results of the present study revealed the significant positive effects of seed priming on A. millefolium seed germination, seedling emergence and early growth

Effect of Organic Fertilization and AMF Inoculation on Yield and Floral Quality Parameters of Common Marigold

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

Sensitivity of Seed Germination to Salt Stress in Teff [Eragrostis tef (Zucc.) Trotter]

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

The Role of Mulching with Residues of two Medicinal Plants on Weed Diversity in Maize

In the present study, there were studied the effects of mulch with the residues of two aromatic and medicinal plants (Sideritis scardica Griseb and Echinacea purpurea) on weed flora and first growth of a maize crop. A field and a pot experiment were conducted at Agricultural University of Athens. In particular, the field experiment was conducted under organic conditions, while in the pot experiment special attention was paid to the first growth of maize plants under the effect of plant residues. Our results showed that there was a significant effect of plant residues on weed flora. The incorporation of Sideritis sp. residues resulted to a lower number of different weed species (low richness) and an intense effect on most weed species. During the early growth stages of maize there was a satisfactory control of the broadleaf weeds after the incorporation of S. scardica, resulting to a significantly lower biomass. However, this effect progressively disappeared, with E. purpurea mulch progressively showing a higher phytotoxic activity. The pot experiment revealed that there was not any negative effect of mulching on maize seed germination, emergence and early growth