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Natural resistance of Bambusa vulgaris to termite and powder-post beetle attack in laboratory and graveyard tests
2018 - IRG/WP 18-10925
Deterioration is the major setback to the utilisation of bamboo products. To enhance bamboo utilization, an understanding of the level of resistance to degradation is important. In this study, level at which Bambusa vulgaris will naturally resistant attack by subterranean termites and powder-post beetles were evaluated. B. vulgaris aged 2, 3 and 4 years were subjected to attack by subterranean termites and powder-post beetles for six month in a short span field tests. After the exposure period, the weight loss due to attack were determined in order to evaluate the level of natural resistance to the selected degrading insects. There was significant variation in the termite resistance among the three age classes while no variation occurred along the culm length. In contrast to termite resistivity, resistance to powder-post beetles infestation varied significantly along the culm length from base to the top while the resistance among the three age classes were similar. The bamboo was grouped into resistant classes based on the age and the portion of the culm from which samples were extracted. Bamboo aged 4 exhibited highest resistance to termites and were therefore placed in “Resistant” class while bamboo from age 3, basal and middle portion were placed in “Moderately resistant” class. The resistance of B. vulgaris from all the age classes and culm portion against powder-post attack was poor and were placed in class IV. B. vulgaris resistivity to termite and powder-post attack had significant negative correlation with culm age and portion respectively. Generally, the findings of this work showed B. vulgaris natural resistant to termite depend on culm age while that of powder-post is indifferent to age or the culm portion.
N A Sadiku, S O Bada
A note on the distribution of copper-chrome-boric (CCB) along the culm length of freshly felled bamboo treated by modified Boucherie process
2005 - IRG/WP 05-40317
Preservative treatment of green and dry bamboo poses severe problems. A number of bamboo/ wood preservatives (Chemical formulations) for the destroying organism like fungi, borers and termites etc. In this paper we reported preliminary results of treatment of fresh green round bamboo attached with baranches by modified Boucheri process. Sample full length of an Indian species of bamboo Dendrocalamus strictus is taken for the treatment. Bamboo culm is treated with 8% solution of copper-chrome-Boric (CCB) for 6 hours. The treatment was discontinued after six hours. When the out coming solution showed almost equivalent concentration and bamboo was removed from the equipment. Branches were removed and bamboo culm was stored under cover for slow drying to allow diffusion of salts from the vessels to the adjoining tissues. The results from the study indicate excellent penetration, retention and absorption of CCB preservative in bamboo culm.
R Lal, C N Vani
Invasion and colonisation of bamboo culm material by stain and decay fungi
2002 - IRG/WP 02-10453
Two distinct stages of the fungal infection of bamboo culms can be identified: entry into the culm itself (invasion) and further colonisation by spread within the culm wall tissue. This laboratory study aimed to characterise different invasion strategies of a variety of fungi. Well-known isolates of white- (Coriolus versicolor, Schizophyllum commune), brown- (Coniophora puteana, Gloeophyllum trabeum, Poria placenta), soft-rotting (Chaetomium globosum) and stain fungi (Lasiodiplodia theobromae) were used as test organisms in culm wall material of Moso Bamboo (Phyllostachys edulis). By giving the fungus defined “entrances” into the specimen and by introducing a “baiting” method, routes of entry taken by fungal hyphae during infection of the culm tissue were investigated using light and scanning electron microscopy. he results show clearly that typical bamboo decay fungi such as S. commune and C. globosum can infect the fresh, undamaged culms via the dense outer epidermis if growth conditions are optimal. No part of the culm was identified as a barrier. Small bore holes in the epidermis, caused by penetrating hyphae were identified using scanning electron microscopy. It is proposed that this was the main pathway of entry into the culm tissue.
G Kleist, I Morris, R J Murphy
The natural durability and preservative treatability of 11 bamboo species
2010 - IRG/WP 10-10708
Tests on the natural durability and preservative treatability of 11 common bamboo species were conducted. The results showed that there was a linear relation between bamboo density and its preservative retention by mass, and the preservative retention of bamboo reduced while its density increased. The test also showed that there were significant differences in the natural durability of bamboos, but the natural durability of bamboo was not related closely to its density, and 11 bamboos were all belonged to non-durable grade, lasting less than 2 years in filed exposure.
Chen Lifang, Su Haitao, Zhang Yanjun, Wang Yuxia, He Xuexiang, Ma Hongxia, Xie Guijun
Microwave Modification of Bamboo Culm to Improve Permeability
2012 - IRG/WP 12-40592
Bamboo is a woody, valuable and strong material that has been used for a long time. In spite of its numerous beneficial properties, bamboo is susceptible to attack by fungus and insect therefore preservative treatment is regarded as necessary. Preservative treatment must provide sufficient uptake and even distribution in the culms for adequate protection. The treatability of dry bamboo, however, is generally poor. In dry state, distorted structure of bamboo nodes obstructs liquid penetration. Recently, microwave technology was evaluated for improving wood permeability. Microwave significantly improves wood permeability as a result of the modification. Microwave applicator where wood meet the waves was designed to suit heating purposes. Specially designed PC-1 applicator was developed for bamboo culm modification. The applicator allows microwave energy to heat the culm walls and not specifically heat the centre. This paper is studying the use of microwave technology for bamboo culm to improve its permeability. It includes comparing the conventional and PC-1 applicators for bamboo treatment. The results show that the PC-1 applicator allows surface modification of bamboo and creates short fractures that allow liquid to penetrate into the culm walls without necessarily filling up the central hollow section. Microwave energy modification of 0.05 kWh achieved optimum fractures for greatest uptake (173.59 kg/m3), which is about three times greater than non-modified samples.
K Sugiyanto, P Vinden, G Torgovnikov, S Przewloka