ion between fibre lignin and laccase in qualitative difference in temporal phases than laccase does alone. Resulting distinguished lignin modifications may have consequences for subsequent fibre behaviour (Barsberg 2002). Lund & Felby (2001) applied a range of mediators in laccase-modification of spruce and pine fibres and found ABTS and PPT (phenothiazine-10-propionic acid) to be effective in enhancing wet tensile strength of paper handsheets made from the pulp. Similar results were obtained with ABTS by Elegir et al. (2005, 2007). Treatment of fibres with laccase and gallic acid were also reported to change wet tensile strength (Chandra et al. 2004b), indicating that laccase-mediator system can influence properties of the fibre surfaces. Various mediators are therefore currently tested in MDF production with laccase in order to achieve higher reactivity between laccase and lignin and better board properties (Müller et al. 2006). The unfortunately limited availability of cheap and non-toxic mediators is of course a restricting factor in such approaches (Rochefort et al. 2004, Morozova et al. 2007). So far, in laccase-mediated bleaching of lignocellulosic fibres 1-hydroxybenzotriazole and the lignin-derived phenols acetosyringone and syringaldehyde acid have been positively tested as mediators whereas negligible effects were seen with p-coumaric acid (Ibarra et al. 2006, Camamero et al. 2007, Gutiérrez et al. 2007). Oppositional ABTS-mediated depolymerisation and polymerisation effects on kraft lignin samples (González Arzola et al. 2006, Hernández Fernaud et al. 2006) imply that the doses and times of mediators and enzymes applied have to be expected to play an important role in activating of fibre material. In line with this, dosages of 4-hydroxybenzoic acid were most influential in laccase-mediated modification of paper pulp (Chandra et al. 2004a). Further to applications of mediators to improve mechanical properties by laccase action, recent studies suggest that a successive xylanase and laccase treatment with or without mediators might also be useful in efficiently modifying fibre surfaces at least in paper production. As the gallic acid mediator treatment, successive xylanase-laccase treatment has been reported to increase the wet tensile strength of paper (Chandra & Raugaskas 2005, Kapoor et al. 2007). 2-component adhesives based on lignin and enzymes In the wood composite industry, addition of lignosulphonates (spent sulphite liquor) or kraft lignins from sulphate pulping, to conventional PF resins is targeted at replacing parts of the phenol component made from petrochemicals (e.g. see Roffael & Rauch 1971, Shen 1974, Nimz 1983, Ayla & Nimz 1984, Danielson & Simonson 1998a,b, Tejado et al. 2007; further reading in Chapter 16 of this book). Formaldehyde from the PF resin may act in such mixtures as a cross-linker between the reactive sites of the technical lignins and the synthetic phenol binder (Kuo et al. 1991, Vázquez et al. 1999, El Mansouri & Salvadó 2006, 2007). As first

/pdf/wood-production-wood-technology-and-biotechnological-impacts-5gpvoylcbz.pdf

Wood production, wood technology, and biotechnological impacts

The performance and suitability of different substrates for the soilless culture of tomato plants ( Lycopersi- cum esculentum Mill., cv. Belladona) were studied over a 5-month period in a closed soilless culture system employing five different substrates (perlite, pumice or maize and their mixtures with 50% shredded maize stems in an unheated glasshouse). Plants grown in a maize stem-containing medium produced earlier fruits, followed by pumice. Plants grown in pumice and perlite substrates obtained lower total yield; a higher yield was associated with the addition of maize shredded stems. Pumice + 50% maize and 100% maize produced higher total number of fruits per plant. Fruit quality parameters such as mean fruit weight, fruit firmness, total soluble solids, titratable acidity, ascorbic acid and carotenoids were influenced by the treatment, while EC, pH and dry matter content were not. The results suggest that the addition of maize in perlite and pumice could improve inorganic substrates properties for tomato soilless culture, leading to higher yields and better fruit quality.

Impacts of the substrate medium on tomato yield and fruit quality in soilless cultivation

Efficacy of organic amendments used in containerized plant production: Part 1 – Compost-based amendments

In recent years, a wide range of soilless culture techniques have been developed and commercially introduced for intensive production of horticultural crops, particularly in greenhouses. Reasons for replacing soils as growing media arise from plant protection problems with soil-borne pathogens and environmental regulations against groundwater pollution with nitrate and pesticides. The aim of this study was to compare some growing indexes of greenhouse tomato that were cultivated in some substrates, such as perlite, date-palm peat and coco peat. The research was conducted in a completely randomized design with 6 replications. The treatments were coco peat + perlite (v/v=50%)‚ date-palm peat + perlite (v/v=50%)‚ perlite (100%) and date-palm peat (100%). Papadopolus formula was used for nutrient solution during plant growth with fertigation method. Also temperature, humidity and irrigation rate was constant for all treatments. Comparison of means showed that the media had no significant effect on concentration of nutrient elements in fruit such as N, P, K and yield in all treatments. Minimum and maximum amount of fruits yield was in date-palm peat and perlite treatments respectively. That had no significant difference with other treatments. Higher amount of total soluble solids (TSS) related to coco peat + perlite treatment that has not any significant difference with date-palm peat + perlite, perlite and date-palm peat treatments. Also, culture substrates had no significant difference on the amount of ascorbic acid. The results showed that date-palm peat is an appropriate media for soilless culture with suitable physical and chemical properties, availability and low cost. Therefore, it can be a new substrate that is introduced for replacing other media.

	 

	Key word: Soilless, substrate, date-palm peat, total soluble solids, ascorbic acid.

/pdf/effect-of-some-culture-substrates-date-palm-peat-cocopeat-1ifj0rzvni.pdf

Effect of some culture substrates (date-palm peat, cocopeat and perlite) on some growing indices and nutrient elements uptake in greenhouse tomato

Different substrates have several materials which could have direct and/or indirect effects on plant growth and development. Therefore selecting the best substrate between the various materials is imperative to plant productivity. This research was carried out with using a completely randomized design with three treatments and seven replications. The treatments were including perlite, date-palm waste and soil. During plant growth irrigation rate, temperature, humidity, pest control for all treatments were similar. Cucumis Stativus cultivar was used for seeds. During plant growth Papadopolus formula with fertigation method used for nutrient solution. Some physiochemical characteristics of cultivation substrates were measured. The growth indices of cucumber plant were measured at the end of growth period. Results showed that higher amount of yield, biomass weight, SD, plant height, root weight, LAI and fruit TSS related to date-palm waste that had a significant difference with soil at 5% level but generally had not any significant difference at 5% level as compared with perlite substrate.

/pdf/comparison-of-date-palm-wastes-and-perlite-as-culture-4p0mqow1wz.pdf

Comparison of date-palm wastes and perlite as culture substrates on growing indices in greenhouse cucumber

SummaryTrials over two years aimed to characterize the physico-chemical properties and high-temperature responses of ecologically sound untreated organic substrates coconut (Cocos nucifera L.) coir and carbonated rice husk in relation to that of rockwool using tomatoes (Lycopersicon esculentum Mill.) as a test crop. In all substrates, water-filled pore space and water holding capacities were larger and air filled pore space was smaller. Bulk densities, water holding capacity and water-filled, air-filled and total pore spaces were lower in carbonated rice husk than coconut coir and rock wool. These values in coconut coir and carbonated rice husk were much increased with use. Most of the chemical properties, namely cation exchange capacity, electrical conductivity, pH, nitrate-N, P, K, Ca and Mg of these substrates were within recommended levels as growing media. There were no significant differences in plant height, stem diameter, individual fruit weight, percent fruit set, harvest index, ascorbic acid, to...

Characterization of the physico-chemical properties of environmentally friendly organic substrates in relation to rockwool

Some fundamental properties of a chaotic three-dimensional non-linear system of the Lorenz type systems were studied. The invariance, dissipation, bifurcation and the strange attractors were investigated and analyzed one 1-scroll, two 2-scroll and two 4-scroll attractors by adding control   parameters to this system. The relationship and connecting function for the 2-scroll attractor of this system were also explored. DOI: http://dx.doi.org/10.3329/jbas.v36i2.12959 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 159-170, 2012

Shariful Islam Khan

Papers

Characterization of the physico-chemical properties of environmentally friendly organic substrates in relation to rockwool

A Chaotic Three Dimensional Non-Linear Autonomous System Beyond Lorenz Type Systems