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  • Author or Editor: S. Srivastava x
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Abstract  

A short-term greenhouse pot culture study was carried out to study the agronomy efficacy of P sources for cotton crop in a vertisol. The sources of P were single super phosphate (SSP), diammonium phosphate (DAP) and nitrophosphate tagged with 32P and applied at three rates (30, 60 and 90 kg P2O5 ha−1). The results indicated that the dry matter yield (DMY) of cotton shoot, P uptake, percent P derived from fertilizer (%Pdff) and Avalue of the soil increased significantly with increasing fertilizer rate, whereas the percent fertilizer P utilization (%FUP) was found to be higher at lower fertilizer rates. Among the fertilizer sources SSP was found to be superior in enhancing DMY of cotton, P uptake and %FUP as compared to other fertilizers. %Pdff was found to be at par in SSP and DAP treatments and was significantly higher in comparison to NP and reverse was true in case of A-value of the soil. Results on equivalent ratio showed that SSP and DAP are equally efficient, whereas, 1 kg P as SSP was equivalent to 7.47 kg P as NP. In general, efficacy of phosphatic fertilizers for cotton crop in vertisol was found to be in order of SSP>DAP>NP.

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Abstract  

Using the pulse radiolysis competition kinetic technique, OH radical rate constants with 12 metal DTPA complexes were determined in neutral aerated aqueous solutions. They are in the range of /1.3–5.9/×109 dm3 mol–1s–1. To a first approximation, the rate constant was found to decrease linearly with an increase in the field strength of the metal ion (q/r2).

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High-performance thin-layer chromatography (HPTLC) on silica plates, with two successive mobile phases, has been used for analysis of seven amine azo dye isomers prohibited under a German ban. Dichloromethane was used for the first development, to a distance of 4.5 cm. After drying, the second development was performed with toluene–tetrahydrofuran, 10 + 1 (v/v), to a distance of 8.5 cm. Spots were visualized at λ = 254 nm. Eighteen amines have been studied by use of the method. The limit of determination (X) and the correlation coefficient in the range X to 5X are reported for each amine. To increase the sensitivity of detection, the UV spectrum was acquired for each amine and the wavelength of maximum absorbance (λmax) was used to establish the limit of determination. Synthetic mixtures and dye samples have been resolved and quantified.

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Abstract  

Cumulative yields of the short lived105Ru,107–109Ru isotopes in the spontaneous fission of252Cf have been determined by a fast radiochemical separation followed by gamma spectrometry. The cumulative yields of105Ru,107Ru,108Ru and109Ru are 7.20 ±0.30, 6.35±0.35, 5.89±0.29 and 4.08±0.30 respectively. The value of109Ru has been determined for the first time. From the cumulative yields the chain yields for mass chains 105, 107, 108 and 109 are obtained.

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Molecular detection of Cucumber mosaic virus in various chrysanthemum cultivars was attempted by RT-PCR and Southern hybridization tests using CMV specific primers and cloned probes, respectively. A pair of primers was designed from a conserved region of the Cucumber mosaic virus coat protein (CMV-CP) gene, capable of amplifying a product of ~650 bp from various CMV strains. RT-PCR using the total nucleic acid from infected leaf samples and the specific primers resulted in positive amplification of an expected size band of ~650 bp in most of the samples. The identity of the PCR amplicons was checked by Southern hybridization using the a32P-labelled DNA probes prepared from the cloned coat protein gene of a well-identified strain of CMV isolated from Amaranthus. Positive signal of hybridization of PCR products and CMV probes confirmed the identity of fected chrysanthemum samples.

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Two highly resistant genotypes of wheat viz. HD 29 and DWL 5023 and one highly susceptible genotype WL 711 against Karnal bunt (KB) disease were studied for their difference in morphological features, growth para­meters and isozyme patterns. It revealed that both the resistant geno­types were bearing higher number of spikelets with short internodes in the spike as compared to the susceptible genotype. In contrast WL 711 had significantly higher number of stomata in sheaths, flag leaf base, booted glumes and rachis. The hair count was significantly high on the glumes and rachis of HD 29 and DWL 5023 than on WL 711. HD 29 possessed significantly narrow glume opening distance between lemma and palea followed by DWL 5023 and WL 711. Moreover, the period between ear emergence and anthesis was short in HD 29 followed by DWL 5023 and WL 711. Out of the twelve isozyme systems performed using seeds and seedlings of the genotypes, majority of them gave rise to comparatively higher number of bands in HD 29 and DWL 5023 than in WL 711. How­ever, specific band(s) for each genotype were very less. Cluster infor­ma­tion was the same for morphological data and isozymic banding patterns in Unweighted Pair Group Method with Arithmetic Averages (UPGMA) analysis where both the resistant genotypes together formed a cluster leaving susceptible genotype alone in a separate cluster. Comparison between morphological features and isozyme patterns of the wheat genotypes in relation to KB disease is discussed.

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Abstract  

Cerium(IV) molybdate, prepared under the optimum conditions of concentration, acidity etc., shows exchange capacity of 0.96 meq per g of exchanger. The sorption of a large number of metal ions has been investigated and the compound shows promising behaviour as cation exchanger. Numerous separations of analytical and radiochemical interest have been performed on the columns of this exchanger with great efficiency.

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Abstract  

The sorption of univalent, bivalent and trivalent ions has been studied on chromium ferrocyanide gel. The studies reveal a high sorption capacity for Cs+, Tl+, Ag+, Cu2+, Zn2+, Cd2+, Fe3+ and Th4+. The sorption of monovalent cations show purely ion-exchange mechanism while the uptake of bivalent and trivalent cations is non-equivalent in nature. Single elution of Rb+, Cs+ and Tl+ has been performed from the columns of this exchanger and the recovery is almost complete in all the cases. Cu2+ and Ag+ get completely adsorbed on the gel column and their elution is not possible probably due to the formation of some new solid phases. Depending on the Kd values of the metal ions, a large number of separations of radiochemical as well as analytical importance can be performed on the columns of this exchanger material.

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