No abstract

The study was developed in Nova Maringá -MT. The objectives of this work were to evaluate the sawn timber yield, the use of wood residues and the quantification of products for the species Qualea paraensis (cambará) and Erisma uncinatum (cedrinho) in three diametric classes: Class A -40.0 to 49.9 cm; Class B -50.0 to 59.9 cm; Class C -60.0 to 69.9 cm. Four replicates per class were evaluated, totaling 12 logs per species of varied lengths. The sawn timber yield did not show a statistical difference between diametric classes for both species. Average yield for Qualea paraensis was equal to 43.97% and for Erisma uncinatum, 42.05%. The residues use increased the total yield in 4.40% and 6.52% for Qualea paraensis and Erisma uncinatum, respectively. For Erisma uncinatum, the sawed products with the highest production were the board in the primary unfolding and the short board in the residues use. As for Qualea paraensis, there was more production of rafters and short battens in the same processes. ResumoRendimento em madeira serrada e aproveitamento dos resíduos de Qualea paraensis ducke e Erisma uncinatum warm. Produção de madeira serrada e utilização de resíduos de Qualea paraensis Ducke e Erisma uncinatum quente. O estudo foi desenvolvido no município de Nova Maringá -MT e os objetivos foram avaliar o rendimento em madeira serrada, o aproveitamento dos resíduos madeireiros e a quantificação dos produtos serrados produzidos para as espécies Qualea paraensis (cambará) e Erisma uncinatum (cedrinho) em três classes diamétricas: Classe A -40,0 a 49,9 cm; Classe B -50,0 a 59,9 cm; Classe C -60,0 a 69,9 cm, com quatro repetições por classe, totalizando 12 toras por espécie de comprimentos variados. O rendimento em madeira serrada não apresentou diferença estatística entre classes diamétricas para as duas espécies, sendo o rendimento médio para a Qualea paraensis igual à 43,97% e para a Erisma uncinatum igual à 42,05%. O aproveitamento dos resíduos aumentou em 4,40% e 6,52% o rendimento total do desdobro das toras das espécies Qualea paraensis e Erisma uncinatum, respectivamente. Para a espécie Erisma uncinatum os produtos serrados com maior produção foram a tábua no desdobro primário e a tábua curta no aproveitamento dos resíduos, enquanto que, para a espécie Qualea paraensis houve maior produção de caibro e sarrafo curto nos mesmos processos. Palavras-chave: serraria, madeira tropical, produtos madeireiros. _______________________________________________________________________________________

The low sawn timber yield of tropical species is caused by quality of the logs, among other factors. The objective was to evaluate the quality of logs and the sawn wood yield for export of the tropical species Dinizia excelsa Ducke, Hymenolobium heterocarpum Ducke, Dipteryx odorata (Aubl.) Willd., Astronium lecointei Ducke and Qualea paraensis Ducke. The log quality parameters analyzed were conicity, flattening, curving, buttresses, cracks, heartwood percentage and net volume. After sawing, the sawn wood yield was determined. The values of conicity (0.92 cm.m− 1) and flattening (96%) did not differ between species. Qualea paraensis and Hymenolobium heterocarpum showed a better classification for curving. Astronium lecointei showed no buttresses. Qualea paraensis showed better classification for annular ring cracks and Dipteryx odorata for surface and diametrical cracks. Dipteryx odorata (86.75%) and Hymenolobium heterocarpum (82.4%) showed better results for heartwood percentage. Dinizia excelsa (90.1%), Dipteryx odorata (83.6%) and Hymenolobium heterocarpum (82.6%) logs showed higher net volume values. The yield of sawn timber for export differed between species and ranged from 23.9–40.2% for Dinizia excelsa and Qualea paraensis, respectively. There was variation in the quality of the logs and the yield of sawn timber for export due to the distinctive characteristics of the species evaluated.