Responses of <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f. sp. <Emphasis Type="Italic">niveum</Emphasis> to exogenously added sinapic acid in vitro

To assess the influence of phenolic acids from plant root exudates on soil pathogens, we studied the effect of sinapic acid added to chemically defined media on the growth and virulence factors of Fusarium oxysporum f. sp. niveum. Sinapic acid inhibited the growth and conidial formation and germination of F. oxysporum f. sp. niveum by 6.7–8.8% and 11.2–37.3%, respectively. Mycotoxin production by F. oxysporum f. sp. niveum was stimulated by 81.6–230.7%. Pectinase, proteinase, cellulase, and amylase activities were stimulated at a lower concentration of sinapic acid, while they were inhibited at a higher concentration. It is concluded that sinapic acid inhibited the growth and conidial germination of F. oxysporum f. sp. niveum and decreased the pathogenic enzymes’ activity at higher doses.     

Effect of pruned material,extracts, and polyphenols of tea on enzyme activities and microbial community structure in soil

Pruning is a regular management practice performed in tea fields, but its effects on soil properties and microbial community structures have not been well explored. Effects of tea pruned material, tea extracts, and tea polyphenols application on soil properties and microbial characteristics, including pH, soil enzyme activities, culturable microbial population, and bacterial community, were investigated in a pot-incubation experiment lasting for 10 weeks. Results indicated that returning of tea pruned material or its extracts significantly increased the soil pH as compared to control. The soil invertase and urease activities, as well as the culturable microbial population treated with pruned material were much higher than those in control, while polyphenol oxidase activity was similar among different treatments. Denaturing gradient gel electrophoresis analysis of bacterial community indicated that the Shannon’s diversity index (H) of all nine treatments receiving additives slightly decreased as compared to control. Pruning returning specifically induced several beneficial bacterial species, including Brevibacterium sp. and Burkholderia sp. In conclusion, pruning returning alleviated soil acidification, induced soil enzyme activities, stimulated culturable microbial population, and reshaped the microbial community. This research suggests that this management could be applied as an alternative agricultural practice in tea cultivation.     

Kinetics of Chromium Ion Removal from Tannery Wastes Using Amberlite IRA-400 Cl− and its Hybrids

A strong base anion exchange resin Amberlite IRA-400 Cl^? and its hybrids with Mn(OH)₂ and Cu(OH)₂ are used for the removal of chromium from the synthetic spent tannery bath. The recovery is examined by varying the experimental conditions, viz., resin dosage, stirring speed, and temperature. The rate of chromium removal by Amberlite IRA-400 Cl^? increased almost four times when the resin dosage was increased from 0.2 to 1.0 g. Furthermore, the rate of chromium sorption almost doubled when the stirring speed was increased from 100 to 1,000 rpm, suggesting that the sorption is a diffusionally controlled process. The chromium removal capacity also increased with the rise of temperature, showing the endothermic nature of the process. The results are explained with the help of film diffusion, particle diffusion, and Lagergren pseudo-first-order kinetic models. The kinetics results of the Amberlite IRA-400 Cl^? are compared with its hybrid anion exchange resins IRA-400 Mn(OH)₂ and IRA-400 Cu(OH)₂. It is found that the hybrid ion exchangers have greater removal ability and fast kinetics as compared to the parent exchanger.     

Prevalence and molecular diagnosis of <Emphasis Type="Italic">Trypanosoma evansi</Emphasis> in Nili-Ravi buffalo (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>) in different districts of Punjab (Pakistan)

The prevalence of Trypanosoma evansi was investigated in 1,250 Nili-Ravi buffaloes of mixed age and sex by polymerase chain reaction (PCR) for the first time in Pakistan. DNA of the trypanosomes was isolated with TRIREAGENT®. The assay was employed using primers ESAG 6/7, specific for a 237-bp fragment from T. evansi genomic DNA. The samples were screened for the presence of T. evansi also by stained thin smear. Forty-four (3.5%) samples were positive by microscopy, while 97 (7.7%) samples were identified by PCR, indicating the high sensitivity of PCR for surveying the disease in epidemiological studies.     

Preparation and Optimization of Amino Acid Chelated Micronutrient Fertilizer by Hydrolyzation of Chicken Waste Feathers and the Effects on Growth of Rice

For the preparation of amino acid chelated fertilizer, chicken feathers were hydrolyzed with sulfuric acid (H₂SO₄; 6M) and potassium hydroxide (KOH; 6M) separately in the presence of different catalysts. Under acidic conditions, the catalyst zinc sulfate, gave minimum ammonium but a maximum conversion rate of organic nitrogen (N) into amino acids (19% higher than control). Under alkaline conditions, sodium sulfide showed maximum amino acid-N and conversion rate (37% higher than control). The catalyst doses showed a continuous increase in the conversion rate and were highest at 12%. The ratio of 1:3 feathers: hydrolytic agent showed maximum conversion rate. Hydrolytic time had a nonsignificant effect under acidic conditions, but under alkaline conditions a hydrolytic time of 14 h gave the maximum conversion rate. The chelation experiment results showed that the ratios (2:1, 2.5:1, and 3:1) showed almost equal chelation rates, except the 1:1 ratio of hydrolysis product to salt. Iron (Fe), copper (Cu), and manganese (Mn) showed maximum chelation rates under acidic pH, while zinc (Zn) showed maximum chelation rate at an alkaline pH. Temperature and chelation time had a nonsignificant effect on chelation rate. Comparative study results of amino acid chelated Zn and Fe fertilizers, ethylenediaminetetraacetic acid (EDTA) chelated Zn and Fe fertilizers, and zinc sulfate (ZnSO₄) and iron sulfate (FeSO₄) fertilizer foliar application to upland rice showed that a 1/100 dilution of amino acid chelated Zn and Fe fertilizers increased growth parameters from 22–73%, while EDTA chelated Zn and Fe fertilizers caused an increase of 15–63%, and ZnSO₄ and FeSO₄ increased growth parameters from 11–35% over the control. After fertilizer application, increase in chlorophyll contents was 11–17%, 3–6%, and 8–12%, respectively, over control. Therefore, amino acid chelated micronutrient fertilizer is used in small amounts, has a low cost, and high rates of return.     

Improving the performance of bread wheat genotypes by managing irrigation and nitrogen under semi-arid conditions

Wheat (Triticum aestivum L.) productivity is generally affected by water limitation and inadequate nitrogen supply especially under semi-arid environment. The current study was conducted to determine whether the crop yield and irrigation water use efficiency (IWUE) could be manipulated through alteration of nitrogen and irrigation application. To meet the desired objectives, a two-year field study was carried out in 2013–2014 and 2014–2015, in a split-split plot arrangement with three factors i) irrigation in main plots, ii) nitrogen in sub-plots, and iii) twenty genotypes in sub-sub plots on a sandy loam soil. The analysis of variance revealed that the wheat performance was affected by genotypes and alteration of irrigation and nitrogen application with respect to IWUE and final grain yield. IWUE under water stress conditions was observed 56% higher than normal irrigated. Much higher values of IWUE under water stress indicated that the existing optimum water requirements of the crop needs to be revaluated. The regression model indicated that addition of nitrogen and irrigation patterns along with morphological traits cannot explain variation in yield related traits more than 65% under semi-arid conditions. Therefore, for better crop yields in semi-arid environment, more physiological parameters should be considered in evaluation of yield.     

Effect of lead pollution on soil microbiological index under spinach (Spinacia oleracea L.) cultivation

Purpose

Lead (Pb) pollution is appearing as an alarming threat nowadays in both developed and developing countries. Excessive Pb concentrations in agricultural soils result in minimizing the microbiological activities which leads to the decrease in crop production. A pot experiment was conducted with the purpose to examine the deleterious effect of Pb on microbiological index under spinach cultivation.

Materials and methods

Pb was added to 5 kg soil in each pot (with 6 seeds/pot) using Pb(NO₃)₂ at the rate of 0, 150, 300, 450, and 600 mg kg^?1 with three replications in completely randomized design. All soil microbial, enzymatic, and chemical properties and plant growth parameters and nutrient uptake were measured by standard methods.

Results and discussion

Both soil and plant measured parameters decreased after the addition of Pb (150, 300, 450, and 600 mg Pb kg^?1 soil) treatments with the passage of time (from 15 to 60 days) compared with control (CK). However, high Pb levels had more suppressive effect, therefore, highest Pb level (600 mg Pb kg^?1 soil) significantly (P?<?0.05) decreased the microbial biomass carbon (5.59-fold); microbial biomass nitrogen (N; 11.71-fold); microbial biomass phosphorus (P; 25.1-fold); dehydrogenase (4.02-fold); phosphatase (9.40-fold); urease (9.26-fold); pH (1.40-fold); spinach shoot (2.17-fold) and root (2.54-fold) length; shoot (2.36-fold) and root (2.69-fold) fresh weight; shoot (3.90-fold) and root (3.50-fold) dry weight; chlorophyll content (5.60-fold); carotenoid content (4.29-fold); plant macronutrients uptake, i.e., N (4.38- and 2.97-fold), P (3.88- and 6.58-fold), K (3.88- and 4.6-fold), Ca (6.60- and 6.70-fold), and Mg (5.57- and 4.45-fold); and plant micronutrient uptake, i.e., Zn (2.39- and 3.05-fold), Cu (3.70- and 2.62-fold), Fe (4.13- and 3.23-fold), and Mn (4.17- and 4.09-fold) in spinach shoot and root, respectively. Conversely, highest Pb level, i.e., 600 mg Pb kg^?1 soil significantly (P?<?0.05) increased the biomass carbon (C)/nitrogen (N) (4.69-fold) and C/P (6.01-fold) ratios, soil extractable Pb (5.87-fold), and Pb uptake in spinach shoot (3.58-fold) and root (4.38-fold), respectively, at the end of the experiment, i.e., day 60.

Conclusions

Pb contamination significantly decreased the soil microbial and enzymatic activities, pH, spinach plant growth, and nutrients uptake in all the samples spiked with Pb. The degree of the influence increased with the increased Pb concentrations and incubation time, showing that Pb threshold is strongly associated with the extent of Pb concentration and time to accumulate. The soil microbial biomass, enzymatic activities, pH, and spinach physiological indices, could be used as a sensitive indicators to reflect environmental stress in soil ecosystems.     

Synthesis,analysis and simulation of carbonized electrospun nanofibers infused carbon prepreg composites for improved mechanical and thermal properties

This paper reports the fabrication, characterization and simulation of electrospun polyacrylonitrile (PAN) nanofibers into pre-impregnated (prepreg) carbon fiber composites for different industrial applications. The electrospun PAN nanofibers were stabilized in air at 270 °C for one hour and then carbonized at 950 °C in an inert atmosphere (argon) for another hour before placing on the prepreg composites as top layers. The prepreg carbon fibers and carbonized PAN nanofibers were cured together following the prepreg composite curing cycles. Energy dispersive X-ray spectroscopy (EDX) was carried out to investigate the chemical compositions and elemental distribution of the carbonized PAN nanofibers. The EDX results revealed that the carbon weight % of approximately 66 (atomic % 72) was achieved in the PAN-derived carbon nanofibers along with nitrogen and lower amounts of nickel, oxygen and other impurities. Thermomechanical analysis (TMA) exhibited the glass transition regions in the prepreg nanocomposites and the significant dependence of coefficient of thermal expansion on the fiber directions. The highest value of coefficient of thermal expansion was observed in the temperature range of 118-139 °C (7.5×10^-8 1/°C) for 0 degree nanocomposite scheme. The highest value of coefficient of thermal expansion was observed in the temperature range of 50-80 °C (37.5×10^-6 1/°C) for 90 degree nanocomposite scheme. The test results were simulated using ANSYS software. The test results may be useful for the development of structural health monitoring of various composite materials for aircraft and wind turbine applications.