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  • Author or Editor: R. S. Singh x
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Wheat is the second most important crop after rice in India and occupies approximately 28.5 million hectare area. Salinity is one of the major factors reducing plant growth and productivity worldwide, and affects about 7% of world’s total land area. In India about 6.73 million hectare land area is salt affected. The aim of this study was to investigate the morpho- physiological and biochemical response of wheat to temporal salinity (ECiw = 10.0 dSm–1) exposures. Ten wheat genotypes were evaluated in two successive growing seasons (2012–2014), with complete randomized design with three replications under both salinity stress and non-stress conditions. The morpho-physiological and biochemical character measured in this investigation, inhibited under both salt stresses (S1 & S2) conditions but much more significantly inhibited under long-term salinity exposure (S2) than S1 because interrupting the metabolic process of plant, resulting in reduced growth and productivity. According to correlation result, selection of high yield genotypes can be done based on plant height (0.649*), tiller plant–1 (0.808**) and leaf area (0.687*). The multivariate morphophysiological and biochemical parameters should be further used to develop salinity tolerance in wheat breeding improvement programmes.

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A study was undertaken to determine the genetics of corn leaf aphid (CLA) resistance in barley under controlled conditions with artificial inoculation at adult plant stage. Inheritance of CLA resistance was investigated in five resistant barley genotypes (EB921, EB2507, Manjula, DL529 and K144) in crosses with susceptible parent Alfa93 in F1, F2, F3 and backcross (BCF1) generations. The aphid inoculation was done using the brush method as well as the detached leaf method. Individual plants were classified in resistant, moderately resistant, susceptible and highly susceptible categories base on number per shoot as well as multiplication of CLA on any of the fresh, young leaf. The plants scored as resistant or moderately resistant were observed twice more at 10 days interval to confirm their reaction. Resistance was governed by a single dominant gene in EB921, DL529 and K144, while it was monogenic recessive in Manjula and EB2507. These diverse sources may be used in breeding for CLA resistance in barley improvement programme.

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Abstract  

Sorption behaviour of monovalent Rb+, Tl+ and Ag+ is studied on chromium fericyanide gel. Log Kd vs log concentration plots show that Rb+ and Tl+ are sorbed through ion exchange mechanism in a higher concentration range of ammonium nitrate or nitric acid, whereas the adsorption of Ag+ is irreversible. It was found possible to elute Rb+ and Tl+ on the columns of this gel by 4 mol dm−3 NH4NO3 and 10 mol dm−3 HNO3, respectively. Binary separations of Rb+ and Tl+ from a number of other metal ions were achieved as other ions were found practically unadsorbed on these columns and were eluted with water of pH 2–3. Achieved separations are of radioanalytical and analytical importance.

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Abstract  

The radiotracer technique has been applied to find the transference number of anion/cation constituents of iodine-alcohols “inner chargetransfer complexes” and it is deduced that the anions are the main charge carriers.

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Abstract  

The distribution ratios for the extraction of Zr(IV) by TBP and its binary mixtures with DMSO or Py in n-dodecane in the presence of HNO3, and HClO4 have been determined. Based on stoichiometric and slope analysis methods a possible mechanism for the extraction has been proposed.

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Two field experiments were conducted during the kharif (rainy) season of 1999 and 2000 on a loamy sand soil to study the effect of various pre- and post-emergence herbicides on the weed infestation and grain yield of soybean. The presence of weeds in the weedy control plots resulted in 58.8 and 58.1% reduction in the grain yield in the two years compared to two hand weedings (HW) at 30 and 45 days after sowing (DAS), which gave grain yields of 1326 and 2029 kg ha-1. None of the herbicides was significantly superior to the two hand weedings treatment in influencing the grain yield. However, the pre-emergence application of 0.75 kg ha-1 S-metolachlor, and 0.5 kg ha-1 pendimethalin (pre-emergence) + HW 30 DAS were at par or numerically superior to this treatment. There was a good negative correlation between the weed dry matter at harvest and the grain yield of soybean, which showed that effective weed control is necessary for obtaining higher yields of soybean.

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The study examined the vegetation composition and phenotypic traits at five sites, differing in degree of disturbance, in a tropical dry deciduous forest of India. A total of 49 species and 4033 individuals (≯= 9.6 cm dbh) were enumerated in the cumulative 15-ha permanently protected area. The study revealed that the five sites represented five more or less different communities (species combinations with different dominants). On the basis of phenotypic traits, these communities or sites could not be discriminated, either by proportion of species belonging to different trait categories or by the cumulative importance value of the trait categories. As a result, disturbance did not affect the predominant traits. Evidently, all the communities shared the major phenotypic traits of the dry deciduous forest. Small leaf size, medium leaf texture, rough bark texture and medium deciduousness characterized the dry deciduous forest vegetation. Both the percent of species and importance values were larger for medium or less deciduous trait categories than for highly deciduous trait, representing a trade-off between water loss and the period of dry matter synthesis.

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