Yadav E.,Janta College Bakewar |
Singh M.,Brahmanand College |
Saxena P.N.,Dr. M.G.R. Educational and Research Institute
National Academy Science Letters | Year: 2014
Synthetic pyrethroids form a group of widely used insecticides in agriculture and home formulations. The widespread use of these pyrethroids and the corresponding increase in animal and human exposure had led to sustained interest in their toxicology. α-cypermethrin and λ-cyhalothrin are two important type-II pyrethroids which intensively control a wide range of pests. Most of the SAR studies done so far on pyrethroids are based on the consideration of stereochemical properties and very little attention has been given to SAR studies based on electronic properties. An effort has been made to explain the activity and preferred sites of electrophilic attack in α-cypermethrin and λ-cyhalothrin on the basis of atomic charges, molecular electrostatic potentials at surfaces, distribution of frontier molecular orbitals, highest occupied molecular orbital energy (E-HOMO), lowest unoccupied molecular orbital energy (E-LUMO) and HOMO-LUMO gap of two molecules. © 2014 The National Academy of Sciences, India.
Pandey M.,Janta College Bakewar |
Chaturvedi B.K.,Rbs College |
Singh S.,Janta College Bakewar |
Singh S.,Rbs College |
Shukla P.K.,Janta College Bakewar
Journal of the Indian Society of Soil Science | Year: 2015
The current study was carried out to assess the status of forms of sulphur (S) in soils of Etawah district, Uttar Pradesh. Separate set of field experiment was carried out during rabi season of 2007-08 and 2008-09 at Etawah to study the effect of sources and levels of S on potato. The total S content in soils of Etawah district ranged from 75 to 190 mg kg-1 with a mean value of 130.9 mg kg-1. The mean values of organic-S, SO4-S and non-sulphate-S were 43.8, 12.1 and 74.2 mg kg-1, respectively. All the forms of S gave significantly positive correlation with organic carbon (OC) indicating S as the integral part of soil organic matter (SOM). Approximately 62% soils under study were deficient in available S. The results of field experiment revealed that the potato (Solanum tuberosum L.) crop responded significantly to applied S through various sources. Tuber yield of potato and starch content in tubers increased significantly with increasing levels of S up to 40 kg ha-1. Sulphur uptake also followed the similar trend of tuber yield. Among the sources of S tested, ammonium sulphate was best with respect to yield, starch content and uptake of S by potato tubers. Next in order were gypsum, elemental S and pyrite. The net return (Rs.135340 ha-1) and B/C ratio (1.91: 1) were higher when ammonium sulphate was used as a source of S. Potato crop grown with 60 kg S ha-1 gave maximum net return (Rs.147305 ha-1) and B/C ratio (2.08: 1). Ammonium sulphate recorded significantly higher S use efficiency and S uptake efficiency over other sources of S. Sulphur use efficiency and S uptake efficiency decreased with 60 kg S ha-1 over lower levels of S application.