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Sundararaj R.,Institute of Wood Science and Technology
Journal of Biopesticides | Year: 2012

This paper reviews the botanicals evaluated against forest insect pests of India and presents the impact of neem and other plant products against major forest insect pests. Various neem products were found effective in field condition against many forest insect pests like the rohida defoliator, Patialus tecomella, the babul defoliator, Taragama siva, the desert locust Schistocerca gregaria, the babul whitefly Acauldaleyrodes rachipora, the spiralling whitefly, Aleurodicus dispersus and the teak defoliators Hyblaea puera and Paliga machaeralis etc. Neem oil and neem oil based formulations were used to contain the populations build up of A. dispersus on roadside plantations of Bauhinia. variegata and Michelia champaca. Neem cake, pongam cake and VAM were commonly applied in combination for the management of sucking pests on seedlings. Other than neem about 58 plant species were reported to have pest management properties on forest insect pests. In these plants, mostly crude extracts were reported to have different type of pest management properties in laboratory condition against defoliating pests. Not much work has been carried out on other group of insects like sap suckers, wood borers, gall inducers etc. Extractives of different parts of Capparis decidua were found to possess aphidicidal principles against three species of aphids viz., Aphis gossypii, Lipaphis erysimi and Mysus persicae. Plant products other than neem were not practically used much for pest control. It is recommended to have national, regional and international coordinated effort to exploit botanicals that are more potent as an integral component of pest management in different cropping systems including forestry.

Dhavala A.,Institute of Wood Science and Technology | Rathore T.S.,Arid forest Research Institute
In Vitro Cellular and Developmental Biology - Plant | Year: 2010

Micropropagation of Embelia ribes was achieved through proliferation of axillary shoots obtained from mature plants. Nodal shoot segments, collected March-May, exhibited high-frequency (75%) shoot initiation when cultured on Murashige and Skoog (MS) basal medium supplemented with thidiazuron (TDZ) at 1.13 μM and indole-3-butyric acid (IBA) at 0.49 μM. Subculture of sprouted shoots from the original explants on medium containing TDZ (1.13 and 0.45 μM) during the first and second subcultures was found essential for further shoot proliferation, while inhibition of shoot elongation by TDZ could be overcome by transferring shoot cultures onto MS medium containing 6-benzylaminopurine (BAP; 11.10 μM) for the third subculture. Treating the explants with an antioxidant mixture of 568 μM ascorbic acid, 119 μM citric acid, and 307 μM glutathione prior to inoculation, coupled with subculture at 2-wk intervals onto fresh medium, both helped to reduce browning of the explants and facilitated production of five to six shoots/explant. MS medium supplemented with BAP (4.44 μM) and IBA (0.49 μM) induced shoot multiplication, producing five to six shoots/explant with a shoot length of 3 to 4 cm over a 4-wk culture period. Shoots of 3 to 4 cm in length exhibited 100% rooting within 4 wk after transfer to media containing half the nutrient salt concentration of MS medium with 3.69 μM IBA. Ex vitro rooting in the greenhouse from the in vitro shoots treated with 4.93 μM IBA for 30 min exhibited 95% rooting in soilrite™ medium in a 4-wk period. About 85% of micropropagated plants were established successfully in root trainers. Three-month-old, hardened plants could further be successfully established in the field. In 1 yr, by using the above protocol, 3,200 plants could be produced from a single shoot and 2,700 could be established in the field. © 2010 The Society for In Vitro Biology.

Srinivas K.,Institute of Wood Science and Technology | Pandey K.K.,Institute of Wood Science and Technology
Journal of Wood Chemistry and Technology | Year: 2012

Properties of fast-growing timbers with low durability can be improved by thermal modification. Thermal modification is an eco-friendly method of improving durability of wood. In this work, specimens of rubberwood (Hevea brasiliensis) and silver oak (Grevillea robusta) were thermally modified in vacuum between 210 to 240°C for 1 to 8 hours, and their weight loss, color, and chemical changes evaluated. Rate of thermal degradation was determined from weight loss data. The color of the modified wood darkened and was uniform throughout. CIE lightness color coordinate (L*) decreased with treatment severity, while chroma coordinates a* and b* increased initially, but later decreased with increased process severity. FTIR analysis showed degradation of cell wall polymers resulting in generation of structures which are responsible for color darkening of thermally modified wood. Mechanical properties (bending strength, MOR, and bending stiffness, MOE) of heat-treated wood decreased. A decrease in hydroxyl groups reduced the hygroscopic nature, resulting in increased dimensional stability of thermally modified wood. © 2012 Copyright Taylor and Francis Group, LLC.

Srinivas K.,Institute of Wood Science and Technology | Pandey K.K.,Institute of Wood Science and Technology
Journal of Photochemistry and Photobiology B: Biology | Year: 2012

Natural wood, being biological material, undergoes rapid degradation by ultraviolet (UV) radiations and other environmental factors under outdoor exposure. In order to protect wood from such degradation, the chemical structure of wood is altered by chemical modification or heat treatment. In the present study, heat treated specimens of rubberwood (Hevea brasiliensis) were exposed to xenon light source in a weather-o-meter for different periods up to 300 h. Photostability of modified and unmodified wood was evaluated in terms of colour and chemical changes. Light coloured untreated wood became dark upon UV irradiation whereas, dark colour of heat treated wood lightened on UV exposure. CIE lightness parameter (L) decreased for untreated wood whereas its value increased for heat treated wood upon irradiation. Other colour coordinates a and b increased with exposure duration for both untreated and heat treated wood. The overall colour change (ΔE) increased for both untreated and heat treated wood. The Fourier Transform Infrared (FTIR) spectroscopic studies revealed severe lignin degradation of heat treated wood due to UV light exposure. Colour changes and FTIR measurements indicate that thermal modification of wood was ineffective in restricting light induced colour changes and photodegradation of wood polymers. © 2012 Elsevier B.V. All rights reserved.

Venkatesh G.S.,Indian Institute of Science | Deb A.,Indian Institute of Science | Karmarkar A.,Institute of Wood Science and Technology | Chauhan S.S.,Institute of Wood Science and Technology
Materials and Design | Year: 2012

This paper deals with preparation of nanocomposites using modified nanoclay (organoclay) and polypropylene (PP), with, and without compatibilizer (m-TMI-g-PP) to study the effects of modified nanoclay and compatibilizer on viscoelastic properties. Nanocomposites were prepared in two steps; compounding of master batch of nanoclay, polypropylene and m-TMI-g-PP in a torque rheometer and blending of this master-batch with polypropylene in a twin-screw extruder in the specific proportions to yield 3-9% nanoclay by weight in the composite. Dynamic Mechanical Analysis (DMA) tests were carried out to investigate the viscoelastic behavior of virgin polypropylene and nanocomposites. The dynamic mechanical properties such as storage modulus (E'), loss modulus (E') and damping coefficient (tan δ) of PP and nano-composites were investigated with and without compatibilizer in the temperature range of -40 °C to 140 °C at a step of 5 °C and frequency range of 5. Hz to 100. Hz at a step of 10. Hz. Storage modulus and loss modulus of the nano-composites was significantly higher than virgin polypropylene throughout the temperature range. Storage modulus of the composites increased continuously with increasing nano-content from 3% to 9%. Composites prepared with compatibilizer exhibited inferior storage modulus than the composites without compatibilizer. Surface morphology such as dispersion of nanoclay in the composites with and without compatibilizer was analyzed through Atomic Force Microscope (AFM) that explained the differences in viscoelastic behavior of composites. © 2011 Elsevier Ltd.

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