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Precision nitrogen (N) management sustains high grain yield with low N optimum dose and thus may help reduce the escape of reactive nitrogen from soils to the atmosphere. Two-year field studies wer...

Three-year multi-location field experiments were conducted in soils of varying inherent nitrogen (N) supply in diverse agro-climatic zones for improving productivity and mitigating N2O emissions in...

We report perylenediimide-benzimidazolium based fluorescent ‘turn-on’ probe BIM-PDI for selective detection of human serum albumin (HSA) and bovine serum albumin (BSA) proteins. In HEPES buffer (0.1% DMSO), BIM-PDI self-assembles into aggregates and shows absorption maxima at 500 nm and weak fluorescence centered at 577 nm. The addition of HSA or BSA (1 × 10−9–5 × 10−8 M) to the solution of BIM-PDI results in decrease in the emission intensity at 577 nm. However, further increase in concentration of HSA/BSA results in appearance of new blue shifted emission band at 540 nm. The minimum detection limit for HSA/BSA is 3.01 × 10−10 M at 577 nm and 4.2 × 10−8 M at 540 nm. On addition of BSA to the solution of BIM-PDI, the size of the aggregates decreased from 100 to 250 nm to

Site-specific fertilizer nitrogen management (SSNM) could be the best management option to avoid excessive and untimely nitrogen (N) applications in wheat. Field experiments were conducted in soils of varying inherent fertility in diverse agro-climatic zones to provide SSNM strategy for wide range of wheat genotypes. The intensity of leaf colour greenness of the first fully exposed top leaf was measured using leaf colour chart (LCC) and chlorophyll meter (SPAD) at different growth stages. The spectral properties of leaves at different growth stages differed among the different wheat genotypes except at Feekes 6 stage, thus the leaf greenness measured only at this stage can be used to make SSNM decisions. After applying 25 kg N ha−1 at planting and 45 kg N ha−1 at Feekes 2 stage, the leaf greenness of the first fully exposed top leaf measured with LCC at Feekes 6 stage was used to decide the amount of site-specific fertilizer N to be applied as topdressing. The LCC guided fertilizer N dose sustained grain yield to the level as obtained with soil test based N applications with the less use of 20–50 kg N ha−1. The practice of applying additional N or just increasing number of split doses in soils with low Walkley–Black organic carbon content may not improve grain yield unless plants really need it. The SSNM strategy improved agronomic efficiency of applied fertilizer N in different wheat genotypes grown under diverse range of agro-climatic conditions and in soils with variable indigenous N supply.

Selenium (Se), the sister element of sulfur, has gained importance recently as an essential trace element in the plant systems. It uses the transporters of sulfur for its uptake and similar biochemical pathways for its metabolism, which leads to its incorporation in various biomolecules. The wide range of beneficial effects of Se on plants has been established. Low concentrations of Se have been proven to enhance seed germination, growth, photosynthesis, respiratory potential, yield, etc. Its role in protecting the plants against various types of biotic and abiotic stresses has become an area of active research. Various studies have revealed its direct effect on antioxidative defense system thereby increasing the potential of the plants to combat the stressful conditions. Despite of its well documented positive effects, Se still is an intermediate between being beneficial or harmful because of its toxic effects at higher concentrations. Therefore, concentration of Se to be used, is still a matter of contemplation and research.

Over and untimely application of fertilizer nitrogen (N) are the major constrains in improving fertilizer N recovery efficiency in irrigated wheat ( Triticum aestivum L.). Large field to field and seasonal variability further lower fertilizer N recovery efficiency when broad based blanket recommendations are followed. Six field experiments were conducted during 2005 to 2009 at different locations to establish threshold leaf colour greenness to guide in-season need-based fertilizer N topdressings in wheat. Colour of the first top fully exposed leaf as measured by comparison with different shades of green colour on a leaf colour chart (LCC) and wheat grain yield were significantly correlated. The Cate-Nelson plot of leaf greenness expressed as LCC values against relative grain yield of 0.91 indicated that leaf greenness between LCC shade 4 and 5 may guide crop demand driven N applications in wheat. A series of experiments with progressive refinement in treatments were conducted to develop adequate need-based N management strategy using a single threshold LCC value in irrigated wheat. It was found that a dose of at least 25 kg N ha −1 should be applied at planting. At 1st irrigation (crown root initiation) stage leaf greenness cannot be quantified properly using LCC due to small leaf size and thus it did not lead to adequate fertilizer N management decision. At 2nd irrigation (maximum tillering) stage leaf colour of the first fully exposed leaf served as best indicator of inherent soil N supply as well as crop N needs and thus helped guide need-based fertilizer N top dressing for improving fertilizer N use efficiency in wheat. Fertilizer N management strategy based on application of prescriptive doses of 25 kg N ha −1 at planting and 45 kg N ha −1 at 1st irrigation and then a dose of 30 or 45 kg N ha −1 at 2nd irrigation stage depending on colour of the leaf to be ≥LCC 4 or

Brassinosteroids are of ubiquitous occurrence in plants and elicit a wide spectrum of physiological responses. In our study, brassinosteroids were isolated and identified in topmost dormant leaves of tea plants. Six brassinosteriods, i.e. 6-deoxocastasterone, 24-epibrassinolide,3-dehydroteasterone, typhasterol, 3-deoxotyphasterol and 28-homodolicholide, were isolated and identified by GC–MS. All the brassinosteroids identified belong to important components of early and late C6 oxidation pathways proposed for brassinosteroids biosynthesis in plants. It suggests that both pathways are operating in tea to produce brassinolide, the most active brassinosteroid biologically.

The nature of C -5 substituent and the configuration at C -5 carbon of 2,3-diphenyltetrahydrofurans, with chiral centres at C -2, C -3 and C -5, show a remarkable influence on their COX-2 inhibition and selectivity. Out of the eight compounds investigated here, 1b with COOH group and R ∗ configuration at C -5, and 2d with CH 2 SCH 2 CH 3 group and S ∗ configuration at C -5 have been identified as lead molecules for further studies on COX-2 inhibition.