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  • Author or Editor: N. Sharma x
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Abstract  

The complexes of piperidine dithiocarbamate, 2-aminopyridine dithiocarbamate and organotin(IV) of the type R3Sn(L1), R2Sn(L1)2, R3Sn(L2), R2Sn(L2)2, [R=C6H5CH2 (benzyl), p-ClC6H4CH2 (p-chlorobenzyl), L 1=sodium piperidine dithiocarbamate and L 2=sodium 2-aminopyridine dithiocarbamate] have been synthesised and characterised by spectral studies (IR, UV, 1H NMR). Thermogravimetric (TG) and differential thermal analytical (DTA) studies have beeen carried out for these complexes and from the TG curves, the order and apparent activation energy for the thermal decomposition reactions have been elucidated. The various thermal studies have been correlated with some structural aspects of the complexes concerned. From DTA curves, the heat of reaction has been calculated.

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A field study conducted for two years (1995-96 and 1996-97) at the Indian Agricultural Research Institute, New Delhi on a sandy clay loam soil showed that the application of NP increased the total grain production of a rice-wheat-mungbean cropping system by 0.5-0.6 t ha -1 , NK by 0.3-0.5 t ha -1 and NPK by 0.8-0.9 t ha -1 compared to N alone, indicating that the balanced use of primary nutrients was more advantageous than their imbalanced application. The application of farmyard manure (FYM) along with NPK further increased the total productivity of the rice-wheat-mungbean cropping system by 0.3-0.6 t ha -1 , the organic C by 0.13%, the available N by 10.7 kg ha -1 , the available P by 4.7 kg ha -1 and the available K by 15 kg ha -1 compared to NPK after two crop cycles of the system. The results of the present study thus indicate that integrated nutrient management involving FYM and NPK fertilizers is a must for the sustainability of a cropping system.

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Field experiments were conducted for two crop years at the Indian Agricultural Research Institute, New Delhi to study the effect of enriching wheat residue with legume residue on the productivity and nitrogen uptake of a rice-wheat cropping system and soil fertility. The incorporation of wheat residue had an adverse effect on the productivity of the rice-wheat cropping system. When it was incorporated along with Sesbania green manure, not only did its adverse effect disappear but the response to fertilizer N was also increased. There was no response to fertilizer N when Sesbania green manure was incorporated. When wheat residue was incorporated along with Sesbania green manuring, rice responded significantly to fertilizer N up to 120 kg N ha-1 in the first year and to 60 kgN ha-1 in the second year and at these levels of N, Sesbania + wheat residue gave 0.8 to 1.2 t ha-1 more grain, 0.6-1.0 t ha-1 more straw and 8-15 kg ha-1 more N uptake of rice resulting in 0.04-0.17% more organic C, 3-8 kg ha-1 more available P and 17-25 kg ha-1 more available K content in the soil than wheat residue alone at the same rates of N application. The respective increaseas caused by Sesbania green manure + wheat residue over Sesbania green manure alone were 0.3-0.5 t ha-1 in the grain and straw yield, 1-9 kg ha-1 in the N uptake of rice, 0.02-0.10% in organic C, 1-8 kg ha-1 in available P and 35- 70 kg ha-1 in available K content in the soil. These treatments also gave higher residual effects in succeeding wheat than wheat residue alone. The incorporation of residues of both wheat and Sesbania is thus recommended to eliminate the adverse effect of wheat residue and to increase the beneficial effects of Sesbania green manuring.

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Loose smut of wheat is a disease of world wide significance. Resistant cultivars constitute a potentially useful and environmentally benign method of controlling this disease. The genetic basis of resistance in 20 wheat genotypes with resistance to Ustilago tritici race T11 was studied in crosses with the widely grown but susceptible Indian cultivar, PBW 343. These lines were also involved in 10 ‘resistant × resistant’ crosses, to infer diversity for resistance genes in this set. All 30 crosses were developed to the F3 stage. Fifteen parents were inferred to carry dominant genes for resistance to race T11. Ten of these resistant lines (ML 521, W 59, W 1616, W 2484, W 2531, W 5915, W 6202, WL 1786, WL 2956 and WL 3450) had resistance controlled by 2 dominant genes acting in a complementary manner whereas in 4 lines (W 4461, W 5100, W 2615 and WL 3951), there was a single dominant gene and in a single genotype, WL 5907, there were 2 dominant genes with duplicate gene action governing the resistance. In lines W 2139, W 3899, W 4985, W 5450 and W 5792 a single recessive gene conferred resistance. Inheritance in two crosses, one derived from a line possessing a single dominant gene and the other from a line possessing a single recessive gene was re-analyzed and successfully confirmed in F5 generation. The segregation of most of the ‘resistant × resistant’ crosses conformed to the inferences drawn about the parents in the ‘resistant × susceptible’ crosses.

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The F1 and F2 progenies of a ten-parent diallel cross (excluding reciprocals) were analysed for the combining ability of quantitative traits in six-rowed barley (Hordeum vulgare L.). significant differences were indicated between the parents, F1s and F2s for all the characters studied. The gca and sca components of variance were significant for all the traits. Both additive and non-additive gene effects were involved in the genetic control of the characters; however, non-additive gene effects were observed to be predominant. Among the parents RD 2035, RD 2052, RD 2503 and BL 2 were the best general combiners for grain yield and average to high combiners for other important traits.The parents RD 2552 and RD 387 were the best general combiners for dwarfness. The best specific crosses for grain yield were RD 2503 × RD 2585,RD 2035 × RD 2052, RD 2035 × BL 2, RD 2052 × BL 2, RD 2508 × RD 2552, RD 2552 × RD 2585 and Rd 2052 × RD 2552 in both the F1 and F2 generations. These crosses were higher yielders and in most of the crosses one of the parents involved was a good combiner, indicating that such combinations can be expected to produce desirable transgressive segregants. All the best crosses for grain yield also showed average to high sca effects for most of the yield components. Most of the specific crosses for grain yield involved high × average, average × average and average × poor general combiners. To ensure a further increase in grain yield, the combination of desirable yield components is advocated. The inclusion of F1 hybrids showing high sca, and having parents with good gca, in multiple crosses, bi-parental mating or diallel selective mating could prove a worthwhile approach for further amelioration of grain yield in six-rowed barley.

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Abstract  

Thermal decomposition of di- and triphenyltin(IV) complexes derived from potassium salicylhydroxamate (KSHA) of compositions Ph2SnCl(SHA), Ph2Sn(SHA)2 and Ph3Sn(SHA) has been studied by TG, DTG and DTA. Based upon thermal mass losses the transitory formation of diphenyltin oxide, Ph2SnO as the possible intermediate from the decomposition pattern of all the three complexes has been proposed. Both DTG and DTA give well-defined peaks in the appropriate regions. These studies reveal the formation of SnO2 as the ultimate product.

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Abstract

In this study, we have studied the effect of elements Ag, Cd, and Sn as chemical modifiers on some thermal transport properties (thermal conductivity, diffusivity, and specific heat per unit volume) of amorphous Se. Concurrent measurements of thermal transport properties such as effective thermal conductivity (λe), thermal diffusivity (χe), and specific heat per unit volume (ρC v) are used at room temperature for twin pellets of pure Se- and Se-based binary Se98M2 (M = Ag, Cd, and Sn) alloys using transient plane source technique. We have also determined the thermal inertia I T using the experimental values of thermal conductivity and specific heat per unit volume for present amorphous alloys. The increasing sequence of measured thermal transport properties is also discussed.

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Abstract  

The paper analyses 2339 research papers appearing in 330 journals covered in Medicinal and Aromatic Plants Abstracts, India (1983) on the basis of their broad subject fields such as agronomy, phytochemistry, pharmacology and clinical research; their country of origin; plant genera and their species; and by type of investigation. Under each of the broad subject fields and major genera, an attempt has been made to identify the nature and focus of research in different countries through minimal level content analysis. Special focus of the paper has been the analysis of Indian publication output.

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Lactic acid fermentation of carrot as a method of preservation using different lactic acid bacteria, viz. Lactobacillus plantarum, Pediococcus cerevisiae and Streptococcus lactis subsp. diacetylactis as such and in sequence at different temperatures and with varying salt content (2, 2.5 and 3%) were employed in the fermentation of carrot. The differences in fermentation behaviour of different microorganisms were quite contrasting at 26 °C, but the sequential culture started deviating from the very first day and acidity increased up to 6 days. A temperature of 26 °C and salt concentration of 2.5% were the best for lactic acid bacteria (LAB) fermentation of Asiatic carrot as highest acidity (1.40% lactic acid), low pH and low reducing sugars were achieved in sequential fermentation. The LAB count of 7.8×10 8 CFU ml −1 was also higher at these concentrations coupled with higher sensory scores of the products. Among the fermentation types tried, sequential culture fermentation of the vegetables produced the product with higher acidity, low pH and reducing sugars. The sequential culture fermentation imparted the fermented products better flavour, texture and taste than other products fermented naturally or with lactic cultures of Pediococcus cerevisiae, Lactobacillus plantarum and Streptococcus lactis in single separate fermentation. Based on the overall and sensory quality evaluation, the fermented carrot product prepared with sequential culture was the best followed by the product prepared using natural microflora.

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