155 research outputs found
Management of collar rot disease in chili by farmyard manure and commercial biofertilizers
Collar rot of chili (Capsicum annuum L.) is a very destructive disease caused by a soil-borne fungal pathogen Sclerotium rolfsii Sacc. Generally, chemical fungicides are used to combat the menace but this practice is being discouraged because of health and environmental concerns. In the present study, an alternative environment friendly strategy was used to manage this disease by using farmyard manure (FYM) and two commercial biofertilizers namely Biopower and Feng Shou. S. rolfsii inoculated pot soil was amended with 1% and 2% FYM and the two commercial biofertilizers. Inoculation of soil with S. rolfsii only (positive control) resulted in the highest disease incidence (73%) and plant mortality (60%). Biopower and Feng Shou application reduced disease incidence to 20% and 7%, respectively and plant mortality to 0%. Likewise, 1% and 2% FYM amendment reduced disease incidence to 33% and plant mortality to 26% and 7%, respectively. Under biotic stress of S. rolfsii, FYM and biofertilizers applications, either alone or in combination, significantly enhanced root and shoot growth over positive control. S. rolfsii inoculation significantly increased peroxidase and polyphenol oxidase activities in chili plants which were further increased by application of either of the two biofertilizers. The present study concludes that biofertilizers Biopower and Feng Shou alone or in combination with 2% FYM can be effectively utilized to manage southern blight of chili
Mycoherbicidal potential of Alternaria alternata for management of Chenopodium album under field condition
A field experiment was conducted to evaluate the mycoherbicidal potential of Alternaria alternata to control Chenopodium album L., a problematic weed of wheat. Two wheat cultivars viz. Inqalab 91 and Punjab 96 were co-cultivated with C. album in 1:1 crop-weed ratio. Mycoherbicidal formulation was prepared in 20% canola oil emulsion with 107 conidia mL-1 of A. alternata. The mycoherbicidal formulation was sprayed at 2 - 3 and then at 4 - 5 leaf stage of the weed. Application of mycoherbicide significantly reduced the biomass of the target weed species up to 90%. Mycoherbicidal application significantly enhanced number of fertile tillers and 100 grains weight in both wheat cultivars. As a result of mycoherbicidal application, root and shoot biomass was significantly increased in cv. Inqalab 91 but not in cv. Punjab 96. The present study concludes that application of A. alternata in 20% canola oil can reduced growth of C. album resulting in enhanced growth and yield of wheat.Key words: Alternaria alternata, canola oil emulsion, Chenopodium album, mycoherbicide
Asset Pricing Model Conditional on Up and Down Market for Emerging Market: The Case of Pakistan
This study proposes an asset pricing model conditional on up and down market for emerging market and tests its validity in Pakistan on individual stocks of Karachi Stock Exchange from July 2004 to December 2012. The basic capital asset pricing model is also tested. The results indicate that when emerging market undergoes negative market excess return, basic capital asset pricing model is inaccurate to predict stock returns. Although the conditional asset pricing model accurately predicts the risk-return trade off with beta as sole determinant of stock returns when there is up market, however yet it is significantly variant during down market where significant impact of residuals is evinced on stock returns. The market excess returns of up and down markets are also found asymmetric. The study implies that conditional asset pricing model can be an adequate technique for investors and portfolio managers considering investments in emerging markets. Keywords: Asset Pricing Model, Conditional, Pakistan, Emerging Market, Up Market, Down Market. JEL Codes: C21, C22, G10, G12, G1
Modeling Probability of Path Loss for DSDV, OLSR and DYMO above 802.11 and 802.11p
This paper presents path loss model along with framework for probability
distribution function for VANETs. Furthermore, we simulate three routing
protocols Destination Sequenced Distance Vector (DSDV), Optimized Link State
Routing (OLSR) and Dynamic MANET On-demand (DYMO) in NS-2 to evaluate and
compare their performance using two Mac-layer Protocols 802.11 and 802.11p. A
novel approach of this work is modifications in existing parameters to achieve
high efficiency. After extensive simulations, we observe that DSDV out performs
with 802.11p while DYMO gives best performance with 802.11.Comment: IEEE 8th International Conference on Broadband and Wireless
Computing, Communication and Applications (BWCCA'13), Compiegne, Franc
Effect of quinoa biomass and biocontrol fungi on expression of IPER gene in mung bean in Macrophomina phaseolina contaminated soil
Background: Mung bean is a pulse crop of economic significance, grown in Pakistan for its edible seeds. Its production is severely affected by Macrophomina phaseolina, a necrotrophic pathogen. This study was carried out to investigate the effect of different biocontrol fungi on expression of IPER gene in mung bean plants inoculated with M. phaseolina.Methods: Pot trials were carried out by adding different concentration of dry biomass of quinoa (DBQ) and six antagonistic fungi viz. Aspergillus flavipes, Aspergillus versicolor, Penicillium digitatum, Penicillium italicum, Trichoderma pseudokoningii and Trichoderma viride in M. phaseolina infected soils. After four weeks of germination of mung bean seeds, RNA was extracted from roots and leaves by using TRIzol method and cDNA was prepared by using SuperScriptTM IV First-Strand Synthesis Kit. IPER gene expression was studied on qRT-PCR and ACT was used as a housekeeping gene.Results: The expression of IPER gene was higher in positive control (only inoculated with M. phaseolina) than in negative control (no amendment). Moreover, 1 and 2% doses of DBQ showed slightly higher Ct values than in 3% dose where it was dropped down indicating the allelopathic stress of DBQ treated soils. The treatments either with sole application of antagonistic fungi or together with DBQ showed much higher Ct values indicating no stress at all.Conclusion: Plants only inoculated with M. phaseolina showed the highest disease incidence as compared to the negative control. The soils amended with DBQ and antagonistic fungi significantly alleviated the effect of M. phaseolina. The treatments with increased pathogen stress showed reduced Ct values and vice versa.Keywords: Biocontrol; IPER gene; Gene expression; Macrophomina phaseolina; Mung bean
ANTIFUNGAL ACTIVITY OF METHANOLIC ROOT EXTRACT OF WITHANIA SOMMNIFERA AGAINST FUSARIUM OXYSPORUM F. SP. CEPAE
Background: Basal rot of onion (Allium cepa L.) caused by Fusarium oxysporum f. sp. cepae is a common soil-borne disease that causes significant yield losses. Generally, synthetic fungicides are used to combat the menace which cause environmental pollution. The present study was carried out to assess the antifungal activity of Withania somnifera (L.) Dunal, a Solanaceous medicinal plant, against the pathogen of this disease.
Materials and Methods: Different concentrations (from 0.5 to 4%) of methanolic extract of root, stem and fruit of the test plant species were prepared and their bioactivity was assessed against the target fungal pathogen. Methanolic extract of root was further fractionated with n-hexane, chloroform, ethyl acetate and n-butanol. Different concentrations of these extracts viz. 200, 100… 3.125 mg mL-1 were prepared and assessed for their antifungal activities.
Results: Methanolic root extract exhibited the best antifungal activity causing up to 93% decrease in biomass of the fungal pathogen. n-hexane, chloroform and ethyl acetate fractions of methanolic root extract exhibited pronounced antifungal activity resulting in 46–79%, 40–73% and 35–76% reduction in fungal biomass, respectively.
Conclusion: The present study concludes that root extract of W. somnifera possesses potent antifungal constituents which can be used for the control of F. oxysporum f. sp. cepae
Performance improvement in polymer electrolytic membrane fuel cell based on nonlinear control strategies—A comprehensive study
A Polymer Electrolytic Membrane Fuel Cell (PEMFC) is an efficient power device for automobiles, but its efficiency and life span depend upon its air delivery system. To ensure improved performance of PEMFC, the air delivery system must ensure proper regulation of Oxygen Excess Ratio (OER). This paper proposes two nonlinear control strategies, namely Integral Sliding Mode Control (ISMC) and Fast Terminal ISMC (FTISMC). Both the controllers are designed to control the OER at a constant level under load disturbances while avoiding oxygen starvation. The derived controllers are implemented in MATLAB/ Simulink. The corresponding simulation results depict that FTISMC has faster tracking performance and lesser fluctuations due to load disturbances in output net power, stack voltage/power, error tracking, OER, and compressor motor voltage. Lesser fluctuations in these parameters ensure increased efficiency and thus extended life of a PEMFC. The results are also compared with super twisting algorithm STA to show the effectiveness of the proposed techniques. ISMC and FTISMC yield 7% and 20% improved performance as compared to STA. The proposed research finds potential applications in hydrogen-powered fuel cell electric vehicles
Neural network and URED observer based fast terminal integral sliding mode control for energy efficient polymer electrolyte membrane fuel cell used in vehicular technologies
In this research work, a Neural Network (NN) and Uniform Robust Exact Differentiator (URED) observer-based Fast Terminal Integral Sliding Mode Control (FTISMC) has been proposed for Oxygen Excess Ratio (OER) regulation of a Polymer Electrolyte Membrane Fuel Cell (PEMFC) power systems for vehicular applications. The controller uses URED as an observer for supply manifold pressure estimation. NN is used to estimate the stack temperature which is unavailable. The suggested control method increased the PEMFC's effectiveness and durability while demonstrating the finite-time convergence of system trajectories. By controlling the air-delivery system in the presence of uncertain current requirements and measurement noise, the approach ensures maximum power efficiency. The Lyapunov stability theorem has been used to confirm the stability of the presented algorithm. In addition, the suggested method eliminated the chattering phenomenon and improved power efficiency. Given these noteworthy characteristics, the research has the potential to decrease sensor dependence and production costs while also improving the transient and steady-state response in vehicular applications
Curriculum and Political Socialization: a Case Study of Secondary Schools in Pakistan
The political socialization is considered significant for the real democracy which isfurther well thought-out a key to the progress and prosperity of a country. In this study, efforts are made to determine the extent of political knowledge incorporated in the compulsory subjects taught at secondary level. The study was qualitative as well as quantitative in design. The content analysis of the eight compulsory books being taught at secondary level was carried out. In quantitative approach, survey research design was used. Data were collected from 828 Secondary School Teachers (SSTs) by a self-developed Likert Scale to validate the results of the content analysis. The reliability of the tool was determined by computing the value of Alpha coefficient that was 0.91. The collected data were analyzed by using descriptive and inferential statistics. The results of the study showed that neither the curricula nor the teachers were developing the sense of political socialization among the students. It is suggested that a wide range of topics on basic political knowledge should be incorporated in the present curricula. A teacher training mechanism should also be introduced and made functional through which the teachers themselves got interested in developing political socialization among the students
Tree dieback in Punjab, Pakistan
Survey of 10 districts of Punjab viz. Sialkot, Gujranwala, Lahore, Faisalabad, Sheikhupura, Gujrat, Jehlem, Rawalpindi, Sargodha, and Hafizabad were undertaken from March 2003 to March 2004 to study the present status of tree dieback incidence in these areas. A total of 21 tree species were found victim of the dieback disease. The disease incidence, however, varied in different tree species. Furthermore, there was also difference in disease severity in different surveyed districts of the province. Dalbergia sissoo Roxb. and Acacia nilotica (Lam) Willd. ex Delile., were found to be the most affected species in all the districts. Among the commonly grown trees Mangifera indica L., Eucalyptus citriodora Hook., E. camal-dulensis Dehnh., Populus hybrida M. Bieb., Ficus religiosa L., F. bengalensis L., Bombax ceiba L., Syzygium cumini (L.) Skeels., Psidum guajava L., and Albizia lebbeck Benth. were found affected with dieback. The less commonly cultivated species like Toona ciliata (Roxb.) M. Roemer, Heterophragma adenophyllum Seem. ex Benth. & Hook., Ficus glomerata Roxb., Mimosup elengi, Terminalia arjuna Wight & Arn., Grevillea robusta Cunn., Ehretia acuminata R. Br., Platanus orientalis L. and Barringtonia acutangula (L.) Gaertn. were also found victims of the dieback. Termites and fungi were found to be the most common biotic factors responsible for the disease. Among the abiotic factors generally drought and environmental pollution seemed to be the main causes for dieback initiation and severity
- …