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Wheat (Triticum aestivum) seeds were treated with atmospheric pressure gliding arc discharge plasmas to investigate the effects on water absorption, seed germination rate, seedling growth and yield in wheat. The surface architectures and functionalities of the seeds were found to modify due to plasma treatments. 6 min treatment was provided 95%-100% germination rate. For the treatment duration of 3 and 9 min the growth activity, dry matter accumulation, leaves chlorophyll contents, longest spikes, number of spikes/spikelet and total soluble protein content in shoots were improved. The grain yield of wheat was increased ∼20% by 6 min treatment with H 2 O/O 2 plasma with respect to control.

Atmospheric pressure air/Ar/H 2 O gliding arc discharge plasma is produced by a pulsed dc power supply. An optical emission spectroscopic (OES) diagnostic technique is used for the characterization of plasmas and for identifications of OH and O radicals along with other species in the plasmas. The OES diagnostic technique reveals the excitation T x ≈5550-9000 K, rotational T r ≈1350-2700 K and gas T g ≈850-1600 K temperatures, and electron density »-´-() n 1.1 1.9 10 cm e 14 3 under different experimental conditions. The production and destruction of OH and O radicals are investigated as functions of applied voltage and air flow rate. Relative intensities of OH and O radicals indicate that their production rates are increased with increasing Ar content in the gas mixture and applied voltage. n e reveals that the higher densities of OH and O radicals are produced in the discharge due to more effective electron impact dissociation of H O 2 and O 2 molecules caused by higher kinetic energies as gained by electrons from the enhanced electric field as well as by enhanced n. e The productions of OH and O are decreasing with increasing air flow rate due to removal of Joule heat from the discharge region but enhanced air flow rate significantly modifies discharge maintenance properties. Besides, T g significantly reduces with the enhanced air flow rate. This investigation reveals that Ar plays a significant role in the production of OH and O radicals.

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Pattern of morphological variations was studied in seven cultivars of cotton viz. (1) DPL-41, (2) DPL-20, (3) BAC-49, (4) DPL-50, (5) DPL-51, (6) JA/96-B and (7) DPL-90 by metroglyph and index score method (Anderson, 1957). Two most variable characters - plant height at maturity (PHM) and fibre yield per plant (FYP) were selected for X and Y axis, respectively. In metroglyph diagram there appeared two clusters one comprised of 2 and the other comprised of 3 cultivars. Cluster I representing cultivar nos. 1 and 2 and cluster II cultivar nos. 4, 5 and 7. In both the clusters (Cluster I and II) the members are not so closely associated. In cluster I the members seems to form a straight line and in cluster II they form a triangle. An exceptional feature is the off location of two glyphs representing cultivar nos. 3 and 6. Key words: metroglyph analysis; cotton; Gossypium Bangladesh J. Sci. Ind. Res. 42(4), 449-454, 2007