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P. Malathi ¹, R. Viswanathan ¹, P. Padmanaban ¹

Affiliations
1 Crop Protection Division, Sugarcane Breeding Institute, Coimbatore 641 007, Tamil Nadu, IN

Abstract

Effective fungal and bacterial antagonists having hyperparasitism and antibiosis mode of antagonistic activity against Colletotrichum falcatum were selected based on the suppression of pathogen growth and production of cell wall lytic enzyme chitinase. The effective strains were utilized to identify the sources of antifungal proteins suppressing enzymes and toxin, the pathogenicity determinants of Colletotrichum falcatum during their interection The effective biocontrol agents identified against C.falcatum inhibited the production of extracellular enzymes/proteins of the pathogen and also detoxified/inactivated the toxin/enzymes, when the antagonists were grown along with pathogen or its metabolites in liquid cultures as well as at the point of entry, where it failed to elicit characteristic symptoms on the host. Final outcome of the study resulted in identification of high molecular proteins specifically produced by the antagonists to inactivate the pathogenic metabolites in SDS-PAGE.

Keywords

Sugarcane, Colletotrichum falcatum, Secondary Metabolites, Antifungal Proteins.

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U. K. Pandey ¹, Tikam Chabria ¹, P. Krishnamurthy ¹, R. Viswanathan ¹, B. Kumar ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad - 500 016, IN
2 National Geophysical Research Institute, Hyderabad - 500 007, IN

Abstract

Carbon isotope studies on calcite - graphite system yield narrow Δ Cat - Gr values, varying from 3.9 to 4.3, indicating equilibrium between coexisting calcite and graphite. Calcite - graphite geothermometry has assigned temperatures ranging from 630° to 700°C for the calc - granulites found to the NE of Usilampatti area. The inferred temperatures correspond to the retrograde temperatures obtained by cation exchange thermometry on the granulites from other areas in the Madurai Block. These temperatures may correspond to the late isobaric cooling event. X-ray diffraction studies indicate well ordered nature of these graphites and corroborate the findings of isotope geothermometric inferences.

Keywords

Geothermometry, Calc-Granulite, Calcite-Graphite, Carbon-Oxygen Isotopes, X-Ray Diffraction, Usilampatti, Tamil Nadu.

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Chanchal Sarbajna ¹, R. P. Sinha ¹, P. Krishnamurthy ¹, K. V. G. Krishna ², R. Viswanathan ¹, D. C. Banerjee ¹

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Begumpet, Hyderabad - 500 016, IN
2 Atomic Minerals Directorate for Exploration and Research, Nagarbhavi, Bangalore - 560072, IN

Abstract

White coloured alkali beryl from the pegmatites of Mariagalla-Allapatna in Mandya district, Karnataka contains distinctly higher alkali elements (Na, Li, Rb, Ca) and relatively low beryllium oxide (c. 11 % BeO) compared to normal beryl. Beryl occurs mostly between graphic intermediate zone and quartz core in the complexly zoned, spodumene-bearing Li-Cs-Ta (LCT) type pegmatites in this area. The average value (n = 7) for alkali beryl from this area are Na₂O 1.26%, Li₂O 0.6%, Cs₂O, 0.74%, K₂O 0.07 and Rb₂O 0.08%. Cs content in some of the beryls are higher than Na and hence such beryls may be termed as a new Na-Li-Cs type X-ray powder diffraction data for the beryl (a_o = 9.2765-9.339 Å, c_o = 9.2079-9.2487 Å) reveal differences in crystal structure with respect to normal beryls from Royalstone, Massachusetts, USA (a_o = 9.215Å, c_o = 9.192Å) and compares well with the reported alkali beryl from Arizona, USA (a_o = 9.30Å, c_o = 9.20Å) Their refractive index (N_ω) ranges from 1.588 to 1.592 and the specific gravity varies from 2.74 to 2.79.

Keywords

Economic Geology, Geochemistry, Mineralogy, Rare Metal Pegmatites, Beryl, Marlagalla, Karnataka.

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E. V. S. S. K. Babu ¹, O. P. Somani ¹, R. Viswanathan ¹, R. P. Sinha ¹

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad - 500 016, IN

Abstract

The wodginite group of minerals occur in the Challanpara pegmatite, Bastar District, Chattisgarh. Nearly pure wodginite fractions were obtained by heavy liquid and electromagnetic separation. The mineral fractions havc been studied by X-ray powder diffractometiy and electron-microprobe analysis. Challanpara wodginite deviates from ideal formula MnSnTa₂0₈, or ABC₂O₈ by extensive substitutions at the B site. The Challanpara wodginites also host small hut significant amounts of Zr, W and traces of U. X-ray diffraction study indicates that these wodginites show partial cation disorder.. Upon heating the samples to ∼950°C, cell parameters such as interaxial angle P and cell volume showed notable changes suggesting partial ordering of the crystal structure. 'The calculated index of order (Δ) varies in a narrow range from 0.40 to 0.41 suggesting that the examined phases are "partially disordered wodginites".

Keywords

Wodginite, Pegmatite, X-Ray diffraction, Electron microprobe, Challanpara, Bastar, Chattisgarh.

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C. Chinnaraja ¹, R. Viswanathan ¹, M. Sathyabhama ¹, B. Parameswari ², K. Bagyalakshmi ¹, P. Malathi ¹, D. Neelamathi ³

Affiliations
1 Plant Pathology Laboratory, Karnal 132 001, IN
2 Sugarcane Breeding Institute Regional Centre (ICAR), Karnal 132 001, IN
3 Micropropagation Laboratory, Sugarcane Breeding Institute (ICAR), Coimbatore 641 007, IN

Abstract

Yellow leaf caused by Sugarcane yellow leaf virus (SCYLV) is a serious viral disease affecting production and productivity in many ruling sugarcane varieties in India. Usually the characteristic disease symptoms appear during maturity phases of the crop; also many of the infected varieties do not exhibit disease symptoms and disease expression is influenced by virus titre and other factors, including the prevailing climate. The present study was taken up to quantify and compare SCYLV in meristem-derived tissue culture raised in vitro plantlets and asymptomatic sugarcane plants in RT-qPCR by relative standard curve method. The standard curve was prepared with serial dilutions of plasmid standards from 3 × 10⁷ to 3 × 10³ copy numbers of virus target gene. In this assay, copy number of virus population in in vitro plantlets and asymptomatic plants was estimated from 20,314.58 to 4,330.87 and from 8.96 to 0.27 million copies of viruses respectively. Relative expression level of the virus between in vitro plantlets and asymptomatic plants was in the ratio 73.7 : 243,393.1 based on 2^{-(Δ ΔCt). The results clearly established that meristem-derived tissue culture significantly reduced SCYLV population and it is concluded that the relative standard curve method efficiently detects the copy numbers of the target virus in different sugarcane samples.}

Keywords

Asymptomatic Plants, In Vitro Plantlets, Sugarcane Yellow Leaf Virus, Viral Titre.

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R. Viswanathan ¹, S. Ramesh ²

Affiliations
1 Dept of Mech Engg, Paavai Engineering College, Namakkal, IN
2 Annai Mathammal Sheela Engineering College, Namakkal, IN

Abstract

Magnesium alloy is one of the lightest materials currently finding wide applications in the production of aircraft engines, airframes, helicopter components, light trucks, automotive parts and computers parts due to its attractive properties. The difficulty in machining mg alloys with regular cutting tools like high speed steel (HSS), carbide tools requires new cutting tools to be tried. The surface finish is a key quality characteristic in dry turning of magnesium pieces and is often affected by multiple factors within the machining process. In this attempt Mg AZ91D alloy is machined with polycrystalline diamond (PCD) coated cutting tool and the effects of input parameters like cutting speed, feed and depth of cut were studied to evaluate the surface roughness obtained. The input parameters were optimized using Taguchi techniques. It was found that the parameter having greatest influence on the surface roughness was feed rate followed by depth of cut and cutting speed.

Keywords

Magnesium Alloy, Machining, Optimization, Taguchi Technique and Surface Roughness.

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E. Jayashree ¹, R. Viswanathan ²

Affiliations
1 Division of Crop Production and Post Harvest Technology, Indian Institute of Spices Research, Kozhikode- 673 012, IN
2 Department of Food and Agricultural Process Engineering, Tamil Nadu Agricultural University, Coimbatore 641 003, IN

Abstract

Ginger, an underground rhizome, is valued as a spice and is used in both dry and fresh form. The process of peeling is labour-intensive and is a time-consuming operation in post-harvest handling of ginger done manually by women labour. To reduce time and labour requirement, a mechanical ginger peeler having a square mesh drum was developed. Peeling trials were conducted for varying drum loads (6kg, 8kg and 10kg), varying drum speeds (35rpm, 40rpm and 45rpm) and for different peeling durations (5 min, 10 min and 15 min). Optimum machine parameters for maximum efficiency were: drum load of 8 kg per batch, operated at drum speed of 40rpm for peeling duration 15 min. Peeling efficiency and material loss at optimum conditions were determined to be 55.60% and 4.68%, respectively. Dry ginger obtained after mechanical peeling was found to contain essential oil at 2%, oleoresin 4.6%, moisture content 9.82% and crude fibre content 2.5%.

Keywords

Ginger, Mechanical Peeling, Material Loss, Peeling Efficiency, Quality.

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R. Viswanathan , R. Venkatesan ¹

Affiliations
1 Bharath Heavy Electricals Ltd., Tiruchirappalli, IN

Abstract

The Japanese have recently introduced the Twist Arc Narrow Gap Welding Process for welding of thick plates, while the West continues their research and application on Tandem Submerged Arc Welding and Multi wire Submerged Arc Process.

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N. Geetha ¹, R. Viswanathan ¹, T. Ramasubramanian ¹, K. P. Salin ¹, C. Yogambal ¹, P. Nirmala Devi ¹, S. Karthigeyan ², N. Chitra ³

Affiliations
1 Division of Crop Protection, ICAR-Sugarcane Breeding Institute, Coimbatore 641 007, India, IN
2 Division of Crop Improvement, ICAR-Sugarcane Breeding Institute, Coimbatore 641 007, India, IN
3 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, India, IN

Abstract

In this study, we report Phenacoccus saccharifolii (green) on sugarcane in Tamil Nadu, India, though an earlier unre­ported isolated occurrence was observed by us in the farmers’ fields at Pugalur, Tamil Nadu. This pest has now become a major threat to sugarcane cultivation across the state as it can often kill the infested canes with or without the association of the fungal disease, pokkah boeng. Field observations revealed that the ratoon crop was affected more than the plant crop in the same locality. This species was found in large colonies, primarily between the –2 and +1 leaf of the sugarcane plant and hence, named as crown mealybug. Infestation leads to severe mottling in the leaf whorl and death of the central shoot. To the best of our knowledge, there are no earlier studies on the occurrence of this mealybug on Saccharum spontaneum L. Well-deve­loped colonies showed high activity of three encyrtid para­sitoids, viz. Aenasius phenococci (Ashmead), Aenasius arizonensis (Girault) and Leptomastix dactylopii Howard in the areas surveyed

Keywords

Encyrtid parasitoids, fungal disease, infestation, Phenacoccus saccharifolii, Saccharum spontaneum, sugar-cane.

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