Effect of plant growth regulators on two different types of eggplant flowers regarding style length and fruit setting

Aim of study: (i) to explore differences between eggplant flowers capable of setting fruit including long (LGs) and medium style flowers (MEs) and those which suffer from severe problems with fertility and fruit setting including short style ones (SRTs); (ii) to study the effect of plant growth regulators on floral morphology and fruit setting. Area of study: Isfahan University of Technology, Isfahan, Iran, 2017 and 2018. Material and methods: First the floral morphology and initial fruit setting of 13 eggplant genotypes from Iran were investigated. Then the differences between LGs and SRTs of two genotypes were explored. Finally, the effect of 1-naphthaleneacetic acid (NAA) and spermidine (Spd) on floral morphology and initial and final fruit setting of these two genotypes was determined. Main results: Results showed SRTs were not capable of fruit setting. Compared to SRTs, LGs had larger central canals, higher protein, total sugar, reducing sugar and K concentrations, as well as longer polar axis and pollen tubes and greater pollen viability. Although 1.5 mM Spd and 20 mg L-1 NAA resulted in increasing of LGs and MEs, and also total initial fruit set, surprisingly, no significant differences were observed in the final yield and final fruit set between the control and these treatments. Researching highlights: Since the rate of fruit dropping was higher in those treatments compared to the control, plants with more SRTs likely regulate their final load by abscising their flowers, and plants with more LGs regulate them by abscising their fruits

Evaluation of Morpho-physiological Responses of Iranian Rice Landraces and Improved Genotypes to Iron Deficiency in Nutrient Solution

Excessive application of P fertilizers, use of the bicarbonated water sources for irrigation concomitant to a  low level of organic matter have resulted in widespread iron deficiencies in crop plants in Iran. One of the strategies to overcome this problem is to select tolerant genotypes to iron deficiency (i.e. iron-use-efficient genotypes) or bred genotypes with high-micronutrient-uptake ability. Therefore, this experiment was conducted to study the behavior of twelve Iranian rice landraces and improved genotypes to iron deficiency (Tarom Mahalli, Amol 2, Musa-Tarom, Gharib, Shiroudi, Bejar, Neda, Nogouran, Jozdan, Sazandegi, Zayande Roud, and Kouhrang) as exposed to two levels of chelated iron fertilizers, including 5mM (iron deficiency) and 50mM (no iron deficiency) in Yushida nutrient solution culture.  A factorial experiment based on a completely randomized design with four replicates was carried out in Soilless Culture Center at Isfahan University of Technology, Isfahan, Iran in 2013. The results showed that the iron content, shoot and root dry weights, total dry weight, leaf area, root length and volume and the number of tillers were significantly affected by genotypes, iron fertilizer, and their interaction. The mean dry weights were 0.215, 0.138, and 0.255 g per plant in northern landraces, northern improved, and central Iranian genotypes under no iron deficiency condition, but they were decreased by 25.7, 35.2, and 23.0% under iron deficiency condition, respectively. Based on the magnitude of decrease of total biomass under iron deficiency condition, genotypes such as Musa-Tarom, Bejar, and Zayande Roud seemed to be more tolerant in comparison to Jozdan, Amol 2, and Shiroudi

The Combined Effect of Different Nitrogen Levels and Planting Arrangement on Weed Interference with Linseed and Seed Berseem Clover Intercropping

Intercropping is one of the effective components of sustainable agriculture. In order to assess the effects of nitrogen application and planting arrangement on linseed and berseem clover leaf area, light absorption and their yield an experiment was conducted as a split plot based on randomized complete block design with three replications at the Research Farm of College of Agriculture, Isfahan University of Technology in 2012. The main plots included three nitrogen rates (0, 30 and 60 kg/ha of nitrogen) and subplots were different planting arrangement of linseed and berseem clover (monoculture of linseed, 70% linseed: 70% berseem clover, 70% linseed: 50% berseem clover, 50% linseed: 50% berseem clover, 50% linseed: 70% berseem clover, monoculture of berseem clover). The highest weed dry weight (286 g/m2) was obtained in monocultures of linseed when 60 kg/ha nitrogen was applied. The highest percentage of light absorption (85.3%) was achieved at different planting arrangements with application of 30 kg/ha nitrogen. The highest  seed yield of linseed (53.19 g/m2) and berseem clover (72.6 g/m2) were obtained in monocultures and 0 and 30 kg/ha nitrogen treatments, respectively. In general, linseed and berseem clover intercropping with application of 30 kg/ha nitrogen were proven beneficial as they led to the greater yield and successful weed control

Evaluation of mechanical and wear properties of Ti-xNb-7Fe alloys designed for biomedical applications

A group of Ti[sbnd]xNb[sbnd]7Fe (x\ua0=\ua00, 1, 4, 6, 9, 11\ua0wt.%) alloys was designed and produced by cold crucible levitation melting process. The microstructural characteristic of the alloys with Nb addition and its effect on their mechanical properties as well as wear resistance were investigated. Microscopic and phase analysis results show that all the alloys, except for the Ti[sbnd]11Nb[sbnd]7Fe, exhibit orthorhombic α“ and body-centred cubic β phases, while Ti[sbnd]11Nb[sbnd]7Fe alloy consists of only β phase. It is proposed that increasing the Nb content enhances β phase stability and its proportion in the microstructure of the designed alloys. Depending on the proportion of β and α” phases, Ti[sbnd]xNb[sbnd]7Fe alloys show varied hardness (3.57–5.92\ua0GPa) and compressive strength (1990–2093\ua0MPa). Additionally, they present wear rates in the range of 3\ua0×\ua010–1\ua0×\ua010\ua0m/m which correlates well with the changes in the corresponding microstructures and mechanical properties. Among the studied alloys, Ti[sbnd]11Nb[sbnd]7Fe with β phase microstructure, presents the lowest elastic modulus (86\ua0GPa) and the highest compressive strain (41.5%) along with high compressive strength, hardness and wear resistance. Therefore, it is suggested that this β-type Ti[sbnd]11Nb[sbnd]7Fe alloy is a promising candidate, more suitable than the commercially used CP[sbnd]Ti and Ti[sbnd]6Al[sbnd]4V, for orthopedic applications

Evaluation of the mechanical and wear properties of titanium produced by three different additive manufacturing methods for biomedical application

Commercially pure titanium, as a widely used metallic biomaterial, was fabricated using dissimilar additive manufacturing (AM) methods, namely selective laser melting (SLM), laser engineered net shaping (LENS) and wire arc additive manufacturing (WAAM). Microstructures as well as mechanical and wear properties of the produced titanium samples were studied. Diverse microstructural features were related to the different linear energy densities and cooling rates induced by each AM method. Tensile testing evaluation indicated the highest yield and ultimate tensile strengths as well as elastic energy for titanium produced by SLM. However, the maximum ductility was obtained in the WAAM-fabricated titanium due to its larger grain size and slightly higher densification. All the mechanical properties obtained were either superior or comparable to those of cast and powder metallurgy produced titanium. Fracture surface analysis showed the presence of mainly coarse and fine dimples for WAAM and SLM-produced samples, respectively. This was consistent with the grain size of each sample. Wear performances and mechanisms were also examined and the results were in agreement with the values obtained from the hardness to elastic modulus ratios (H/E and H/E)

Nanoindentation and wear properties of Ti and Ti-TiB composite materials produced by selective laser melting

Ti and Ti-TiB composite materials were produced by selective laser melting (SLM). Ti showed an α΄ microstructure, whereas the Ti-TiB composite revealed a distribution of needle-like TiB particles across an α-Ti matrix. Hardness (H) and reduced elastic modulus (Er) were investigated by nanoindentation using loads of 2, 5 and 10 mN. The results showed higher H and Er values for the Ti-TiB than Ti due to the hardening and stiffening effects of the TiB reinforcements. On increasing the nanoindentation load, H and Er were decreased. Comparison of the nanoindentation results with those derived from conventional hardness and compression tests indicated that 5 mN is the most suitable nanoindentation load to assess the elastic modulus and hardness properties. The wear resistance of the samples was related to their corresponding H/Er and H3/Er2 ratios obtained by nanoindentation. These investigations showed that there is a high degree of consistency between the characterization using nanoindentation and the wear evaluation from conventional wear tests