Integrated Weed Management Through Tillage and Herbicides for Wheat Production in Rice-Wheat Cropping System in Northwestern Pakistan

Conservational tillage （CT） in combination with broad spectrum herbicide may be more efficient and economical in controlling weeds, reducing cost of cultivation, and enhancing wheat yield. Field experiments were carried out to evaluate the effect of tillage and herbicides on weeds and wheat yield under rice-wheat cropping system （RWCS）. The results indicated that broad spectrum herbicides particularly, carfentrazone ethyl ester＋ isoproturon （Affinity 50 WDG） reduced weeds density by 93 and 95% compared to control and also produced the maximum grain yield （6 818 and 6 996 kg ha-l） and HI （harvest index, 44.7 and 44.6%） in 2007-2008 and 2008-2009 growing seasons, respectively. The maximum weeds infestation and the lowest yield were recorded in control. Tillage methods significantly influenced grain yield and HI, while no significant effect on all other parameters. The overall mean yield was significantly higher in zero tillage （5 575 kg ha-l） and reduced tillage （5 584 kg ha-l） compared to CT （5 479 kg ha-^-1）. Besides increasing wheat yield, Affinity 50 WDG and zero tillage are important weed management practices that can be integrated into wheat production in RWCS. However, in case of perennial weeds or insect pests＇ infestation, CT in combination with Affinity 50 WDG would be more productive than conservation tillage.

Sensitive Spectrofluorimetric Method for Determination of Fluoroquinolones through Charge-Transfer Complex Formation

A sensitive spectrofluorimetric method was developed for determination of ciprofloxacin (CPFX), levofloxacin (LEV), gatifloxacin (GAT) and moxifloxacin (MOX) in pure, commercial formulations, human urine and plasma. The method is based on charge-transfer (CT) complex with chloranilic acid. Fluorescence intensity of the complexes was measured at emission wavelength ranging from 445-492 nm with excitation wavelengths from 285-330 nm. At optimum experimental conditions, a linear calibration plot was obtained in the concentration range of 20-1000 ng·mL-1, 60-320 ng·mL-1, 20-800 ng·mL-1 and 20 -00 ng·mL-1 for CPFX, LEV, MOX and GAT, respectively with good correlation coefficient in the range of 0.9929-1.0 in methanolic medium. The limit of detection and limit of quantification were found to be 5 ng·mL-1 and 18 ng·mL-1 for CPFX, 12 ng·mL-1 and 40 ng·mL-1 for LEV, 8 ng·mL-1 and 19 ng·mL-1 for MOX, 6 ng·mL-1 and 19 ng·mL-1 for GAT, respectively. The method was found free of interferences from excipients used as additive in pharmaceutical preparations, some common cations and compounds present in urine and plasma as well as co-administered analgesic, vitamins and other drugs. The method was successfully applied for quantification of selected fluoroquinolones in commercial formulations and also in spiked human urine and plasma samples with percent recoveries of 100.0 ± 1.56 and 100.2 ± 1.29 respectively.

Analysis of various semi-numerical schemes for magnetohydrodynamic(MHD)squeezing fluid flow in porous medium

In this article comparative analysis of various semi-numerical schemes has beenmade for the case of squeezing flow of an incompressible viscous fluid between two largeparallel plates having no-slip at the boundaries.The medium of flow contains magnetohy-drodynamic(MHD)effect and having small pores.Modeled boundary value problem is solvedanalytically using Optimal homotopy asymptotic method(OHAM),homotopy perturbationmethod(HPM),differential transform method(DTM),Daftardar Jafari method(DIM)andAdomian decomposition method(ADM).For comparison purpose,residuals of these schemeshave been found and analyzed for accuracy.Analytical study indicates that DTM and DJM arequite good in tem of accuracy near the center of domain[—1,1]but the accuracy reducesconsiderably near the start and end of the given interval.HPM and OHAM residuals indicatethat OHAM surpasses HPM in terms of accuracy in the present case.