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This study aimed to evaluate the physical and mechanical properties of particleboard produced of Toona ciliata with different densities and resin levels. Trees from an experimental plantation located in Corupá-SC were used. The trees were cut into logs collected and samples of all longitudinal positions were used to determine the properties of the wood and the generation of particles. Evaluation of wood properties consisted in determining the wood density and chemical properties, which followed the procedures of COPANT standards and TAPPI, respectively. The panels were produced according to a randomized design, using nominal density of 0,60 g/cm³, 0,70 g/cm³ and 0,80 g/cm³, and 6% and 8% resin and pressed at a temperature of 160° C, at an specific pressure of 4 MPa and in atime of 8 minutes. The physical and mechanical properties were evaluated according to the methodology proposed by the European Standard and the Brazilian Standard, the tests made being apparent density (CEN, 2002d), water absorption and thickness swelling (CEN, 2002b), static bending (CEN, 2002a), perpendicular traction (tension) (CEN, 2002c) and screw pullout resistance (ABNT, 2006b). The results indicated that all treatments coplied with the minimum requirements established by the reference standards. The panels produced with fewer raw materials (density of 0,60 g/cm³ and 6% resin), in addition to meeting the regulatory requirement, indicated a savings of up to 23,73% on the amount of particles and up to 42,80% on the amounts of resin and catalyst, when compared with other treatments. [ABSTRACT FROM AUTHOR]

In this study was analyzed the growth and the productivity in the agroforestal association 'cedar-lime-chaya', to know the optimum initial plantation density (PD). Cedars and limes were placed in a 'Nelder' circle of 3154 m2 which consisted of 20 concentric circles alternating cedars and limes to 1.50 m apart and 10 plants per circle; the chayas was established in a rectangular frame to 1.50 x 3.00 m, superimposed on the 'Nelder' circle. Eight PD was defined, from 2602 to 3772 plants ha-1 with 10 repetitions, to evaluate the following variables: length of main root, radical exploration radius, growth rate, index plant vigor, index leaf area and productions dry biomass. Results showed differences in the below growth, above growth and productivity (α ≤0.05), the below growth in cedars and limes was greater to 2602 plants ha-1, and chayas to 3772 plants ha-1; above growth in cedars and limes was greater to 3270 plants ha-1, and chayas to 2602 plants ha-1; and the major productivity was obtained from 3129 to 3425 plants ha-1. The PD for get a greater growth and productivity was from 3046 to 3297 plants ha-1. [ABSTRACT FROM AUTHOR]

Reforestation in Mexico is important to recuperate the productivity of deforested and degraded areas and to maintain that of commercial forests. Only 40% of reforested areas have an acceptable level of survival. Characteristics of seedlings out planted, including shoot/root ratio, are essential factors for achieving the desired results of high survival and good growth after transplanting. This study describes the characteristics of mahogany (Swietenia macrophylla King), Spanish cedar (Cedrela odorata L.) and "roble" (Tabebuia rosea (Bertol.) DC when planted at two densities (100 and 50 plants/m²) and in two substrates [soil, and soil + compost (S+C)] in a nursery. The S+C treatment had a significant effect on diameter, height, root biomass and the shoot/root ratio. In soil 76% of seedlings had a shoot/root ratio of 3.0 or less and in S+ C, 21 % of seedlings had a ratio less than 3.0. For conifers a ratio of 2/1 is recommended for dry sites and 4/1 for humid sites. For broadleaves the optimum shoot/root ratio is not known. Two months after transplanting in the field more Swietenia produced with the S+C treatment died but less Cedrela and Tabebuia seedlings did. For the three species the seedlings that died were smaller. [ABSTRACT FROM AUTHOR]

Although protocols to propagate large numbers of woody species by in vitro culture have been developed, microbial contamination of explants is a fundamental problem which limits its application. The objectives of this study were: to identify the donor plant mycobiota and to identify filamentous fungi contaminants at the establishment phase of mahogany, teak, majagua, pine and cedar. Explants of donor plants were placed in moist chamber and were prepared to direct optical microscope of fungal growth. Cultural characteristics and morphological were taken into account to identify filamentous fungi contaminants in the establishment phase. Frequency of all genera identified was determined. Eleven genera of filamentous fungi in donor plants and twenty genera in the establishment of forest species were identified. The genera Botryodiplodia, Cephalosporium, Diplodia, Dreschlera, Geotrichum, Gloeosporium Helminthosporium, Memnoniella, Oidiodendron and appeared only during establishment phase. Others such as Alternaria, Aspergillus, Cercospora, Curvularia, Cladosporium, Colletotricum, Fusarium, Nigrospora, Penicillium and Pestalotia were detected in donor plants and during establishment phase. This indicates that the possible source of contamination was the initial explant. The most frequent genera were Botryodiplodia in teak, Nigrospora in majagua and Alternaria in pine, cedar and mahogany. A phytosanitary plan of defence for donor plants was developed. The plan included systemic and contact fungicides whose spectrum of activity covered the identified genera of fungi. [ABSTRACT FROM AUTHOR]

The current research was developed with the objective to decrease the microbial contamination and to increase the survival in vitro of cedar (Cedrela odorata L.). Reinvigoration of mother plants was carried. Sticks of 1-2 cm of diameter and 25 cm of lenth collected in different periods of time were planted in a greenhouse. Growth regulator solutions were applied to evaluate sprouting, and growing of shoots and rootening. New shoots, sprayed with fungicide to eliminate in vitro contamination, were compared with apexes and nodal segments, without fungicide treatment, that were collected directly from field and the green house. Explants were disinfected with sodium hipoclorite (NaClO)to avoid contamination and placed in culture medium with 6-BAP 0.25 mg.l-1 and AIA 0.125 mg.l-1. The use of growth stimulating sustances increased sprouting and growing of axillary buds, and rooting of sticks. A n 84% of survival and 10% of contamination were achieved with disinfection by immersion of explants during 10 minutes in NaClO 1.5%. The necessity of reinvigoration of starting material to achieve in vitro establishment of cedar nodal segments was demonstrated. [ABSTRACT FROM AUTHOR]