Effect of nitrogen fertilizations, with and without inhibitors, on cotton growth and fiber quality

Considering cotton, one of the most non environmentally friendly crops, new types of fertilizers, such as the urease inhibitor, are now being used for fertilization. Furthermore, the need of increasing the nutrient use efficiency which is an important contributor to yield has arisen. The objective of this study was to assess the impacts of four different urea combinations (Urea, Urea+NI+UI, Urea+NI, Urea+UI) on cotton (Gossypium hirsutum L.) yield and fiber traits. For this purpose, different inhibitors used on urea fertilizer such as nitrification inhibitor (NI), dicyandiamide (DCD), urease inhibitor (UI), N-(n-butyl) thiophosphoric triamide, and a combination of urease (UI) and nitrification inhibitor (NI) (double inhibitor). Additionally, Nitrogen indicators were also used to evaluate the efficiency of these combinations. Two field experiments were conducted in Agrinio and Copaida region, Central Greece during 2019. The total dry weight ranged from 13,027 to 14,481 kg ha-1 in Agrinio area and from 12,567 to 14,136 kg ha-1 in Copaida area. The highest seed cotton yield was recorded under Urea+NI+UI fertilization at 5,145 kg ha-1 application in Copaida area and 5,318 kg ha-1 application in Agrinio area. Also, the total plant nitrogen uptake (kg N ha-1) was affected by the inhibitors NI and UI. The range for Nitrogen Utilization Efficiency (NUtE) index was 9.27 to 23.06. Moreover, results indicated that NI and UI inhibitors have a marked effect on fiber quality such as strength (g Tex-1). In the Mediterranean region of Greece, the combined use of inhibitors UI and NI resulted in higher yield and finest fiber quality

Block Copolymers of Macrolactones/Small Lactones by a "Catalyst-Switch" Organocatalytic Strategy. Thermal Properties and Phase Behavior

Poly(macrolactones) (PMLs) can be considered as biodegradable alternatives of polyethylene; however, controlling the ring-opening polymerization (ROP) of macrolactone (ML) monomers remains a challenge due to their low ring strain. To overcome this problem, phosphazene (t-BuP_4), a strong superbase, has to be used as catalyst. Unfortunately, the one-pot sequential block copolymerization of MLs with small lactones (SLs) is impossible since the high basicity of t-BuP_4 promotes both intra- and intermolecular transesterification reactions, thus leading to random copolymers. By using ROP and the “catalyst-switch” strategy [benzyl alcohol, t-BuP_4/neutralization with diphenyl phosphate/(t-BuP_2)], we were able to synthesize different well-defined PML-b-PSL block copolymers (MLs: dodecalactone, ω-pentadecalactone, and ω-hexadecalactone; SLs: δ-valerolactone and ε-caprolactone). The thermal properties and the phase behavior of these block copolymers were studied by differential scanning calorimetry and X-ray diffraction spectroscopy. This study shows that the thermal properties and phase behavior of PMLs-b-PSLs are largely influenced by the PMLs block if PMLs components constitute the majority of the block copolymers

Block Copolymers of Macrolactones/Small Lactones by a "Catalyst-Switch" Organocatalytic Strategy. Thermal Properties and Phase Behavior

Poly(macrolactones) (PMLs) can be considered as biodegradable alternatives of polyethylene; however, controlling the ring-opening polymerization (ROP) of macrolactone (ML) monomers remains a challenge due to their low ring strain. To overcome this problem, phosphazene (t-BuP_4), a strong superbase, has to be used as catalyst. Unfortunately, the one-pot sequential block copolymerization of MLs with small lactones (SLs) is impossible since the high basicity of t-BuP_4 promotes both intra- and intermolecular transesterification reactions, thus leading to random copolymers. By using ROP and the “catalyst-switch” strategy [benzyl alcohol, t-BuP_4/neutralization with diphenyl phosphate/(t-BuP_2)], we were able to synthesize different well-defined PML-b-PSL block copolymers (MLs: dodecalactone, ω-pentadecalactone, and ω-hexadecalactone; SLs: δ-valerolactone and ε-caprolactone). The thermal properties and the phase behavior of these block copolymers were studied by differential scanning calorimetry and X-ray diffraction spectroscopy. This study shows that the thermal properties and phase behavior of PMLs-b-PSLs are largely influenced by the PMLs block if PMLs components constitute the majority of the block copolymers

Pulsed electromagnetic field - a cultivation practice used to increase soybean seed germination and yield

The aim of the research was to test the effect of pulsed electromagnetic field (PEMF) on soybean seed germination and yield depending on specific field conditions, years of study, exposure duration and frequency. Field trial was conducted on an experimental field of Institute of Field and Vegetable Crops in Novi Sad, Serbia in 2010-2013. Seeds of the soybean (Glycine hispida (Moench)) medium-early cultivar. Valjevka 'were exposed to the PEMF therapy using the impulse generator and strip. Low-frequency (16, 24, 30 and 72 Hz) PEMF was used in the duration of 0, 30, 60 and 90 minutes. Research results indicate that this method can increase seed germination up to 8.00% and yield by 960.5 kg, or 21% in field conditions, which is a significant increase and a solid basis to introduce this practice, primarily in organic production with a very limited use of seed treatment preparations. However, the practice can have an inhibitory effect under an unfavourable combination of exposure duration and frequency. The obtained data were processed using the analysis of variance of three-factorial trials considering all years of study. Due to different meteorological conditions in the study years, analysis of variance was conducted for each year of study and correlations between the tested traits were examined

Effects of tillage and fertilization on some selected physical properties of soil (0-30 cm depth) and on the root growth dynamic of winter barley (Hordeum vulgate cv. Niki)

The root mass of winter barley (Hordeum vulgare cv. Niki) at growth stages 5, 9 and 16 of the Feekes scale increased from 100% (0.272 mg cm-3 soil) to 132% and 139%, respectively. Root mass was always greater in no-tillage (NT) plots than in ploughed-tillage (CT) plots and was also greater where manure was applied in comparison to plots without manure. The root density at growth stages 5, 9 and 16 over all treatments was 0.197, 0.224 and 0.238 cm cm -3 soil, respectively. At growth stage 5, the root density in NT plots was 9% greater than that in CT plots, and in rotary hoed (MT) plots it was 3% greater. At this same growth stage, soil fertilization with NP, farmyard manure (30 t ha-1) and NP plus farmyard manure improved the root density of barley by up to 5, 10 and 11%, respectively, in comparison with control plots. The diameter of barley roots was clearly biggest in CT plots, while in NT plots the thinnest roots were found. The mean diameter was 0.63, 0.75 and 0.78 mm at growth stages 5, 9 and 16, respectively (over all treatments). Significant correlation coefficients were found between root density (RD) and the soil properties bulk density (BD), porosity (P), penetration resistance (PR) and mean weight diameter of aggregates (MWD). For example, the highest r values were as follows: At growth stage 5, r=0.95 (P < 0.001) for P and r=0.86 (P < 0.001) for MWD; at growth stage 9, r=-0.97 (P < 0.001) for PR and r=0.96 (P < 0.001) for P, and finally at growth stage 16, r=0.97 (P < 0.001) for P and r=-0.97 (P < 0.001) for PR