Spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites

Correlation-induced spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites are calculated with realistic parameters in order to provide a quantitative comparison with experimental results for spin stiffness, magnon dispersion, magnon damping, anomalous zone-boundary magnon softening, and Curie temperature. The role of orbital degeneracy, orbital ordering, and orbital correlations on spin dynamics in different doping regimes is highlighted.Comment: 19 pages, 9 figure

Nutrient Management for Higher Productivity of Swarna Sub1 Under Flash Floods Areas

Two field experiments were conducted at Regional Agricultural Research Station, Tarahara, Nepal during 2012 and 2013 to determine the effect of agronomic management on growth and yield of Swarna Sub1 under flash floods. The first experiment was laid out in a split plot design with three replications; and four different nutrient combinations at nursery as main plots and three age groups of rice seedlings as sub plots. The second experiment was laid out in a randomized complete block design and replicated thrice; with three post flood nutrient doses at six and 12 days after de-submergence (dad). The experiments were complete submerged at 10 days after transplanting for 12 days. The survival percentage, at 21 dad, was significantly higher in plots planted with 35 (90.25%) and 40 (91.58%) days-old seedlings compared to 30 days-old seedlings (81.75%). Plots with 35 days-old seedlings produced 5.15 t ha-1 with advantage of 18.83% over 30 days-old seedlings. Plots with 100-50-50 kg N-P2O5-K2O/ha at nursery recorded the highest grain filling of 79.41% and grain yield of 5.068 t/ha with more benefit. Post flood application of 20-20 N-K20kg/ha at 6 dad resulted in higher plant survival and taller plants, leading to significantly higher grain yield of 5.183 t/ha and straw yield of 5.315 t/ha. Hence, 35-40 days old seedlings raised with 100-50-50 kg N-P2O5-K2O /ha in nursery and the additional application of20-20 kg N-K2O /ha at 6 dad improved plant survival and enhanced yield of Swarna Sub1 under flash flood conditions. The practice has prospects of saving crop loss with getting rice yield above national average yield leading to enhanced food security in the flood prone areas of Nepal

Growth, yield attributes, yield and economics of winter popcorn (Zea mays everta Sturt.) as influenced by planting time fertility level and plant population under late sown condition

The field experiment was laid out in split plot design with three replications, assigning in 27 treatment combinations i.e. three sowing dates of Pop corn (Zea mays everta Sturt.)cv. V.L. Amber (15 Dec, 30 Dec and 15 Jan) arranged in main plots and three level of plant population (60000, 80000 and 100,000 plants ha-1) in sub plot. Three level of fertility (100:50:50, 150:65:65 and 200:85:85 kg of N: P2O5: K2O ha-1) apportioned in sub-sub plots at the Research farm, Institute of Agricultural Sciences, BHU, Varanasi (U.P.) during late winter (rabi) seasons of 2009-10 and 2010-11 to study the influenced of planting time, fertility level and plant population on yield attributes, grain yield and economics of winter popcorn (Zea mays everta Sturt.) under late sown condition. The popcorn sown on 15th December recorded highest plant height, leaf-area index, dry matter, popcorn growth rate, yield attributes and yield of pop corn were significantly (P<0.05) affected and recorded highest benefit cost ratio (3.78). While, the maintenance of 80,000 popcorn plants/ha proved optimum for pop corn as it significantly (P<0.05) recorded highest number of kernel cob-1,grain yield (32.61 q/ha) and shelling percentage against density of 60,000 plants, while remained at par in straw yield over 100,000 plants. Application of 200: 85: 85 kg N: P2O5: K2O/ha significantly (P<0.05) increased growth, yield attributes and grain yield over 100: 50: 50 and 150: 65: 65 kg N: P2O5: K2O/ha and fetched the highest B: C ratio (3.14)

Abundance and distribution of gaseous ammonia and particulate ammonium at Delhi, India

This study reports abundance and distribution of gaseous NH<sub>3</sub> and particulate NH<sub>4</sub><sup>+</sup> at Delhi. Gaseous NH<sub>3</sub> and particulate NH<sub>4</sub><sup>+</sup> concentrations were measured during pre-monsoon, monsoon and post-monsoon seasons of the years 2010 and 2011. Average concentrations of gaseous NH<sub>3</sub> during pre-monsoon, monsoon and post-monsoon seasons were recorded as 26.4, 33.2 and 32.5 μg m<sup>−3</sup>, respectively. Gaseous NH<sub>3</sub> concentrations were the highest during monsoon, thought to be due to decay and decomposition of plants and other biogenic material under wet conditions, leading to increased NH<sub>3</sub> emission. The results showed that particulate NH<sub>4</sub><sup>+</sup> was always lower than the gaseous NH<sub>3</sub> during all the seasons. The concentrations of particulate NH<sub>4</sub><sup>+</sup> were recorded as 11.6, 22.9 and 8.5 μg m<sup>−3</sup> during pre-monsoon, monsoon and post-monsoon seasons, respectively. The percent fraction of particulate NH<sub>4</sub><sup>+</sup> was noticed to be highest during the monsoon season, which is attributed to increased humidity levels favouring partitioning into the aerosol phase. On an average, 33.3% of total N-NH<sub>x</sub> was present as particulate NH<sub>4</sub><sup>+</sup>. Higher concentrations of NH<sub>3</sub> noticed during night time may be due to stable atmospheric conditions. The study highlighted that, as compared with rural sites, urban sites showed higher concentrations of gaseous NH<sub>3</sub> in India, which may be due to higher population density, human activities and poor sanitation arrangements

A complete description of the magnetic ground state in spinel vanadates

Capturing the non-collinear magnetic ground state of the spinel vanadates AV$_2$O$_4$ (A= Mn, Fe and Co) remains an outstanding challenge for state-of-the-art ab-initio methods. We demonstrate that both the non-collinear spin texture, as well as the magnitude of local moments, are captured by a single value of the on-site Hubbard $U$ of 2.7~eV in conjunction with the local spin density approximation (LSDA+$U$), provided the source term (i.e., magnetic monopole term) is removed from the exchange-correlation magnetic field ${\bf B}_{XC}$. We further demonstrate that the magnetic monopole structure in ${\bf B}_{XC}$ is highly sensitive to the value of $U$, to the extent that the interplay between on-site localization and local moment magnitude is qualitatively different depending on whether the source term is removed or not. This suggests that in treating strongly correlated magnetic materials within the LSDA+$U$ formalism, subtraction of the unphysical magnetic monopole term from the exchange-correlation magnetic field is essential to correctly treat the magnetic ground state.Comment: 4 pages, 3 figure

Cultural and morphological characterization of rhizospheric isolates of fungal antagonist Trichoderma

The genus Trichoderma contains species that are of a great economic importance due to their ability to act as biological control agents against a large variety of fungal plant pathogens. In the present investigation thirty isolates of the Trichoderma sp. were obtained from the rhizosphere soils of different plants at different locations at Nainital, Almora, Udham Singh Nagar, Derhadun, Haridwar and Tehri Garhwal districts of Uttarakhand (India). The isolates were characterized on the basis of their cultural and morphological characteristics. The cultural characteristics included linear growth, colony colour, pigmentation and growth pattern. Morphological characteristics studied were structure, shape and arrangement of conidiophores, phialides and conidia. Out of thirty isolates, 6 isolates namely PB10, PB13, PB23, PB26, PB27 and PB28 were identified as T. virens and remaining 24 isolates as T. harzianum

Induction of water stress tolerance of mustard plants using Trichoderma as biological seed treatment

Water scarcity is one of the main consequences of changing climate which adversely affects the plant growth and productivity. Enhanced root development results in increased surface area of active absorption for water and nutrient uptake which helps in tolerating abiotic stresses including drought in plants. Trichoderma is well known for its biocontrol and growth promontory effect in plants in addition to alleviate abiotic stress. In our study, thirty isolates of Trichoderma were grown on sterilized cow dung at different moisture content ranges from 5 to 30 percent to investigate their ability to grow and multiply under water stress condition. Mustard plants were grown under glass house condition by treating seeds with selected isolates of Trichoderma subjected to water stress subsequently. All isolates of Trichoderma grew upto 20% moisture whereas only eleven isolates exhibited growth at 10% moisture. Isolate PB23 was only isolate which was able to grow and resulted in 1.0 x109 cfu/g air dried cow dung even at 5% moisture content and induced the tolerance of mustard plants under water stress conditions when applied as seed treatment before sowing