Search Results
You are looking at 1 - 9 of 9 items for
- Author or Editor: S. Mandal x
- Refine by Access: All Content x
Field studies were undertaken for two consecutive seasons to evaluate the bioefficacy of cyazypyr 10% OD, a new molecule belonging to anthranilic diamide group of insecticides, along with imidacloprid 17.8% SL and fipronil 5% SC as standard checks, against the insect pest complex of tomato vis-à-vis its impact on natural enemies and crop health. The toxicity of cyazypyr 10% OD and four other molecules, each at two doses (diluted in 600l water), against the pupal stage of Trichogramma pretiosum Riley, an important egg parasitoid of Helicoverpa armigera Hubn., was evaluated in the laboratory. Cyazypyr 10% OD @ 90 and 105 g a.i./ha was highly effective in controlling the fruit borer, Helicoverpa armigera Hubn., aphid, Aphis gossypii Glov. and white fly, Bemisia tabaci Gen., and increasing the yield of marketable fruits. This insecticide @ 60-105 g a.i./ha effectively controlled the leaf miner, Liriomyza trifolii Burg. Imidacloprid 17.8% SL @ 22.5 g a.i./ha and fipronil 5% SC @ 60 g a.i./ha were also highly effective in controlling the pests. Considering the bioefficacy and yield, cyazypyr 10% OD @ 90 g a.i./ha may be recommended for effective control of pest complex of tomato. Cyazypyr 10% OD @ 45–105 g a.i./ha did not significantly reduce the field population of natural enemies and was safe to the crop even @ 360 g a.i./ha. In laboratory test, cyazypyr @ 90 and 60 g a.i./ha found to be safe to T. pretiosum Riley pupae, causing only 23.17 and 20.73% mortality, respectively.
Abstract
Dilute aqueous solutions of cytosine were irradiated with60Co 
-rays under N2O saturated conditions at different pH and in the presence of Cu(II) ions at neutral pH. The base degradation decreased from neutral to acidic and basic conditions. In the presence of metal ions at neutral pH conditions there was a significant increase in the base degradation compared to that in the absence of metal ions under similar conditions. From the difference absorption spectra and fluorescence behavior of the irradiated solutions it was observed that the major radiolytic products of cytosine under different conditions are cytosine glycols, 5-hydroxycytosine, hydroxy-hydrocytosine and cytosine dimers. The yields of dimers is maximum in neutral conditions and it decreased from basic to acidic conditions. However, in the presence of Cu(II) ions formation of cytosine dimers is completely restricted and there is an increase in the yields of cytosine glycol, hydroxy-hydrocytosine and 5-hydroxycytosine. From the post-radiolytic changes in absorption and fluorescence behavior of irradiated solutions, it is revealed that some of the radiolytic products, namely cytosine glycol and hydroxy-hydrocytosine decompose to 5-hydroxycytosine and cytosine, respectively.
Abstract
Reactions of carbonate radical (CO3 –), generated by photolysis or by radiolysis of a carbonate solution with nickel(II)-iminodiacetate (Ni(II)IDA) were studied at pH 10.5 and ionic strength (I)==0.2 mol·dm–3. The stable product arising from the ligand degradation in the complex is mainly glyxalic acid. Time-resolved spectroscopy and transient kinetics were studied using flash photolysis. From the kinetic data it was suggested that the carbonate radical initially reacts with Ni(III)IDA with a rate constant (2.4±0.4)·106 dm3·mol–1·s–1 to form a Ni(II)IDA species which, however, undergoes a first-order transformation (k=2.7·102·s–1) to give a radical intermediate of the type Ni(II)RNHCHCO 2 – ) which rapidly forms an adduct containing a Ni–C bond. This adduct decays very slowly to give rise to glyoxalic acid. From a consideration of equilibrium between Ni(II)IDA and Ni(III)IDA, the one electron reduction potential for the Ni(III)IDA/Ni(II)IDA couple was determined to be 1.467 V.
Abstract
Reactions of carbonate (CO 3 –· ) and bicarbonate (HCO 3 · ) radicals generated by photolysis of a carbonate or bicarbonate solution at pH 11.2 and 8.5, respectively, with Co(II) complexes of iminodiacetic acid (IDA) and ethylenediaminetetraacetic acid (EDTA) have been studied. The rate constants for the reactions were in the order of 106–107 dm3mol–1s–1. From the time-resolved spectroscopy of the products formed after reaction of CO 3· –· or HCO 3 · , it is observed that CO 3 –· or HCO 3 · oxidize the metal center to its higher oxidation state.
Abstract
When an aqueous solution of Na2[Mo(V)2O4EDTA] (ethylene diamine tetraacetate) was photolyzed in the presence of excess KBr and K2S2O8 at neutral pH, the complex was found to be oxidized due to the reactions of Br 2 –. and SO 4 –. , respectively. Oxidation of the complex was also observed due to the reactions of the complex with radiolytically generated Br 2 –. and SO 4 –. radicals. When the oxidation of the complex with SO 4 –. was conducted in an unbuffered solution, a chain reaction was observed in the oxidation of the complex. The time resolved kinetics for the formation and decay of different transient intermediates and the relevant rate constants were investigated with a flash photolysis technique, and a probable mechanism for the oxidation process was given.
Abstract
The yields for the loss of chromophore of Ni(II) and Cu(II) complexes of metronidazole,G(-Ni(II)M) andG(-Cu(II)M), reached almost zero when their aqueous solutions were 
-irradiated in the presence, of 0.4 mol·dm–3 of MeOH, EtOH,i-PrOH andt-BuOH in aerated medium. However, under N2O saturated conditions, these yields attained limiting values which suggests that the hydroxyalkyl radicals, derived from the alcohols by reaction with OH, react with the complexes in deaerated medium. But in aerated medium they react preferentially with O2. The rate constants for the reactions of the different hydroxyalkyl radicals with the complexes have been determined by the flash photolysis technique and the plausible mechanisms for the reactions have been suggested.
Clay from the Nagrotta area of Jammu (J & K State, India) was calcined at various temperatures. The products were analysed by X-ray diffraction. The mode of loss of hydroxyl group from the structure with respect to temperature is discussed. The results were supplemented by differential thermal analysis. The calcined products were subjected to lime reactivity tests and the data obtained were correlated with those of the above study to investigate the pozzolanic activity at various temperatures.
Three-year (2007/2008–2009/2010) field experiment was conducted at the Directorate of Water Management Research Farm under Deras command in Odisha, India to assess the crop yield, irrigation water use efficiency (WUE), sustainable yield index (SYI), land utilization index (LUI) and changes in soil organic carbon (SOC) for dominant rice systems, viz. rice-maize-rice, rice-cowpea-rice, rice-sunflower-rice, rice-tomato-okra and rice-fallow-rice. Results revealed that crop yield, in terms of total system productivity (TSP) increased by 273, 113, 106 and 58% in rice-tomato-okra, rice-sunflower-rice, rice-maize-rice and rice-cowpea-rice, respectively, when compared to rice-fallow-rice. Irrigation WUE was 49–414% greater in rice-based diversified systems than the existing rice-fallow-rice (2.98 kg ha−1 mm−1). The SYI ranged from 0.65 to 0.75 indicating greater sustainability of the systems. Three crops in a sequence resulted in greater LUI and production efficiency compared to rice-fallow-rice. The gross economic return and benefit-cost ratio was in the order: rice-tomato-okra > rice-maize-rice > rice-sunflower-rice > rice-cowpea-rice > rice-fallow-rice. The SOC storage ranged from 40.55 Mg ha−1 in rice-fallow-rice to 46.23 Mg ha−1 in rice-maize-rice system. The other systems had also very close values of SOC storage with the rice-maize-rice system; there was a positive change of SOC (7.20 to 12.52 Mg ha−1) for every system, with highest in rice-maize-rice system and the lowest in rice-fallow-rice. It is concluded that the appropriate rice-based system would be rice-tomato-okra followed by rice-maize-rice, rice-sunflower-rice and rice-cowpea-rice. Rice-fallow-rice is not advisable because of its lower productivity, lower LUI and economic return.
Genotype × environment (G × E) interaction effects are of special interest for identifying the most suitable genotypes with respect to target environments, representative locations and other specific stresses. Twenty-two advanced breeding lines contributed by the national partners of the Salinity Tolerance Breeding Network (STBN) along with four checks were evaluated across 12 different salt affected sites comprising five coastal saline and seven alkaline environments in India. The study was conducted to assess the G × E interaction and stability of advanced breeding lines for yield and yield components using additive main effects and multiplicative interaction (AMMI) model. In the AMMI1 biplot, there were two mega-environments (ME) includes ME-A as CARI, KARAIKAL, TRICHY and NDUAT with winning genotype CSR 2K 262; and ME-B as KARSO, LUCKN, KARSA, GOA, CRRI, DRR, BIHAR and PANVE with winning genotypes CSR 36. Genotypes CSR 2K 262, CSR 27, NDRK 11-4, NDRK 11-3, NDRK 11-2, CSR 2K 255 and PNL 1-1-1-6-7-1 were identified as specifically adapted to favorable locations. The stability and adaptability of AMMI indicated that the best yielding genotypes were CSR 2K 262 for both coastal saline and alkaline environments and CSR 36 for alkaline environment. CARI and PANVEL were found as the most discernible environments for genotypic performance because of the greatest GE interaction. The genotype CSR 36 is specifically adapted to coastal saline environments GOA, KARSO, DRR, CRRI and BIHAR and while genotype CSR 2K 262 adapted to alkaline environments LUCKN, NDUAT, TRICH and KARAI. Use of most adapted lines could be used directly as varieties. Using them as donors for wide or specific adaptability with selection in the target environment offers the best opportunity for widening the genetic base of coastal salinity and alkalinity stress tolerance and development of adapted genotypes. Highly stable genotypes can improve the rice productivity in salt-affected areas and ensure livelihood of the resource poor farming communities.
