Abstract This research was aimed at investigating the technical feasibility of using carpentry wastes to produce indoor particleboards. The particles came from the Prosopis alba Griseb and Pinus sp. wood planning in the carpentry at the Institute of Wood Technology (IWT) of the Faculty of Forest Sciences, Santiago del Estero, Argentina. Only-algarrobo, only-pine and a 50-50 % mixture of both were the three types of panels produced. It was done this way for the isolated effect of each of the particles (i.e. specific weight, moisture content, particle geometry, wood acidity, bark use) can be determined. The particles were glued using urea-formaldehyde resin. The particle boards made were tested on their moisture content, specific weight, 2 to 24 hs thickness swelling and bending strength variables in accordance with the DIN standards. For the statistical analysis of the results, a completely randomized three treatments and five repetitions was used. The properties were lower than required by the DIN standards. It is thought that this is mainly due to the low values was the shape and dimensions of the particles. According to the results, the only-algarrobo particleboards were those that best behaved under these study conditions.

Resumen Este trabajo se llevó a cabo con el objetivo de investigar la factibilidad técnica del uso de residuos de acabado y desbaste en carpinterías para producir tableros aglomerados para uso interior. Las virutas utilizadas son las que resultan del cepillado de las maderas de Prosopis alba Griseb y Pinus sp. y fueron adquiridas en carpinterías de Santiago del Estero y en la carpintería del Instituto de Tecnología de la Madera (ITM), Facultad de Ciencias Forestales, Santiago del Estero, Argentina. Se fabricaron tres tipos de aglomerados: algarrobo puro, pino puro y mezcla de 50 % de ambas. Este ensayo se planificó así para obtener el efecto aislado de las partículas por provenir de diferentes especies (peso específico, humedad, geometría de la partícula, acidez de la madera, inclusión de corteza). Las virutas fueron encoladas con resina de urea-formaldheído. En los paneles elaborados se determinaron las siguientes variables: humedad, peso específico, hinchamiento a 2 y 24 hs y flexión estática de los paneles según Norma DIN. Para el análisis estadístico de los resultados se utilizó un diseño completamente aleatorizado de tres tratamientos y cinco repeticiones. Las propiedades resultaron inferiores a lo exigido por Norma DIN. La causa principal de los valores bajos fue la forma y dimensiones de las virutas. De acuerdo a los resultados obtenidos los tableros aglomerados elaborados con virutas de algarrobo fueron los que se comportaron mejor en las condiciones del estudio.

Abstract This study is a part of the research project entitled "Non-Wood Forest Products (NWFP) of the Semiarid Chaco Region", which is being carried out at the Faculty of Forestry of the National University of Santiago del Estero, Argentina, since 2011. Its objective is to conduct a survey of the institutions and organizations dealing with NWFP in the region, to determine their activities and other aspects related to the methodology used as well as the problems they face in the production and marketing of their products. This information was relevant in selecting the research lines to be developed and those needing further investigation. Most of the 19 organizations surveyed are involved in both production and extension activities.

Resumen El presente trabajo está comprendido en el marco del Proyecto de Investigación “Productos Forestales no madereros (PFNM) del Parque Chaqueño Semiárido” que se desarrolla en la Facultad de Ciencias Forestales de la UNSE desde 2011. Su objetivo es realizar un relevamiento de las instituciones y organizaciones que trabajan con PFNM en la región del Chaco Semiárido, determinar las actividades que realizan y otros aspectos ligados a la metodología que emplean así como a las problemáticas que enfrentan en la producción y comercialización. Esta información fue relevante para seleccionar las líneas de investigación a profundizar y/o desarrollar en el proyecto. De 19 unidades relevadas, la mayoría se dedican a actividades de producción y extensión conjuntamente.

The purpose of this stage was to determine the influence of particle size and shape of peanut husks on the properties of panels made with urea resin. Panels were made with milled husks (r: 200 Kg/m³) and unmilled husks (r: 81 Kg/m³) and two combinations thereof. The results showed that the panels made with milled husks improved physical and mechanical properties with respect to the panels that incorporated unmilled particles. The density values in panels with milled particles were 628.67 Kg / m³; water absorption 65.3% and 79.75% at 2 and 24 hours respectively, and swelling of 9.9% and 14.35% measured at 2 and 24 hours respectively. Regarding the characterization of mechanical properties of bending, the values recorded in samples prepared with fine particles of peanut husks resulted in MOR: 3.58 MPa, LOP 2.26 MPa and MOE 627 MPa. With respect to toughness, the highest value was observed in particle boards made from unmilled peanut husks: 1.58MPa. The characterized properties are still below the properties of commercial wood panels. Adjustments to the process of preparing the peanut husks plates will be incorporated in future experiences.

El propósito de esta etapa de investigación fue conocer la influencia del tamaño y forma de partículas de cáscaras de maní en propiedades de paneles aglomerados con resina ureica. Se formularon paneles con cáscaras molidas (r: 200 Kg/m³), paneles con cáscaras enteras (r: 81 Kg/m³) y dos combinaciones de las mismas. Los resultados demostraron que paneles compuestos por partículas de cáscaras de maní molidas (finas) mejoraron propiedades físicas y mecánicas respecto de las placas que incorporaron partículas de mayor tamaño. Los valores de densidad en paneles con partículas molidas fueron 628,67 Kg/m³; absorción de agua 65,3% y 79,75% a 2 h y 24 h respectivamente; e hinchamiento de 9,9% y 14,35% a 2 h y 24 h respectivamente. En relación a propiedades mecánicas de flexión, resultaron con módulo de ruptura (MOR) 3,58 MPa, límite de proporcionalidad (LOP) 2,26 MPa y módulo elástico (MOE) 627 MPa. Con respecto a tenacidad (T), el mayor valor fue observado en los tableros elaborados con partículas enteras: 1,58 MPa. De acuerdo a los valores de densidad, las propiedades caracterizadas se encuentran por debajo de las correspondientes para placas comerciales de madera. Ajustes al proceso de elaboración de paneles de cáscaras de maní serán incorporados en futuros trabajos.

O A. apresenta nêste artigo os resultados obtidos em uma experiência de corte das folhas do sisal (Agave sisalana Perrine), na qual se procurou comparar os efeitos da combinação de diversas freqüências e severidades de corte sobre o desenvolvimento, produção e longevidade da planta, assim como sôbre as características tecnológicas da fibra. Ficou provado que, com cortes freqüentes e severos, o ciclo de vida das plantas fica bastante prolongado, ao mesmo tempo que a produção de fibras por unidade de área decai sensivelmente, em conseqüência da redução de tamanho das fôlhas e menor conteúdo de fibras nas fôlhas das plantas submetidas a êsse sistema de corte. Os exames de laboratório demonstraram que, enquanto as características químicas das fibras não eram afetadas pelos sistemas de corte estudados, as características físicas eram, pelo contrário, sensivelmente afetados pelo corte freqüente e severo.

This paper describes the results obtained with the sisal plant (Agave sisalana Perrine) in a cutting trial located in the "Estação Experimental Central do Instituto Agronômico", at Campinas. This trial was designed to compare the effects of four cutting cycles, combined with three levels of severity of cutting, upon growth, longevity, and yield of the sisal plant, and on the quality of its fiber. The experiment was laid out in 4 randomized blocks of 4 plots, each plot having 3 sub-plots. Sub-plot size was of twelve plants spaced 2.5 x 1.5 m and arranged in two rows of 6 plants each. The results can be summarized as follows : (a) The life cycle of the sisal plant was greatly influenced by the cutting method used. The greater the frequency and severity of cutting the slower was the growth of the plant and the longer it took to pole. (b) Light cutting at six to twelve-month cycles was conducive to early poling, and the plant yielded fewer, though heavier, leaves. (c) Heavy cutting at a three-month cycle reduced plant size considerably and induced the formation of short leaves containing less fiber weight per leaf. There was. therefore, a significant decrease in total fiber yield per area. (d) The final fiber yields indicated that a light cutting (30%) at three or six-month intervals gave higher yields per area than any of the other treatments. Life cycle was slightly prolonged by this treatment and significantly more leaves were produced per plant without adverse effects upon leaf weight and actual fiber content. (e) Fiber analysis showed that its chemical characteristics were not affected by the treatments, even by heavy and frequent cuttings. Heavy cuttings, especially at a three--month cycle, had a marked effect on the physical fiber characteristics.

The present paper deals with the influence of four different leaf-cutting cycles combined with three levels of severity of cutting upon the life cycle of sisal plant (Agave sisalana Perrine). According to the results obtained, it may be concluded that less frequent cutting induces the plant to pole earlier, and greater severity of cutting prolongs its life eyele.

Sisal (Agave sisalana Perrine) accounts for about one half of the world's production of hard fibers. In spite os its economic importance pratically no research work has been carried out on this plant. Very little is known about the agronomic problems of its cultivation, while the physiological and genetic problems are nearly unknown. This is perhaps due to the fact that A. sisalana is a perennial plant with a life cycle of 5-8 years and the carrying out of field research work requires a great deal of time and is very expensive. This paper, the first of a series to be published on the agronomic problems of sisal cultivation, presents the data obtained from field trials on distance of planting and its relation to weight and number of leaves produced. The experiments were carried out at the Ribeirão Preto and Pindorama Experiment Stations of the Instituto Agronômico de Campinas. Sisal bulbils about one year old were planted in the latter part of 1939 in 4 randomized blocks of 9 plots each where different distances between and within the rows were used. Production data were obtained by cutting the leaves at one year intervals begining 2 ½ years from date of planting in the field. Only those leaves that were attached to the plant at an angle greater than 45.° in relation to the main axis of the plant were cut each year. Only in the trial at Ribeirão Preto the leaves were counted and weighted by plants. In the poling plants all leaves than existing were taken off, even the youngest ones adjacent to the pole (flower stalk). Descorticator machine for fiber extraction was not available, so that reliable data on fiber yield could not be obtained. A "probable" fiber yield was obtained by using 3% of leaf w r eight as a basis for calculations. This percentage is recognised as an average fiber content usually obtained from sisal leaves. From the data obtained from the spacing trials described in this paper the following conclusions can be drawn : 1. The life cycle from date of field planting to poling stage of most of the sisal plants in these trials varied from 5 to 8 years. A very small number of plants however had not poled even after 8 years when the present experiments were ended. 2. The life cycle of the sisal plants showed a close relationship to planting distances. At the greater planting distances the plants tended to pole much earlier than at closer planting distances. 3. It was observed that there was a marked seasonal incidente of poling. The flower stalk of almost all plants have appeared during the period of January to March. 4. A marked effect to the distance os planting on plot yields, as measured by total leaf weight, was observed. The greater the density of plants per unit area the greater the leaf production. 5. Under present leaf cutting practice, e. g., to cut yearly only the leaves at an angle greater than 45.° in relation to the main axis of the plant, the shorter distances between the rows are not recommended. The narrow spacing between rows not only restricts the passage of workers, but also hinders adequate cultivation (weeding and sucker growth control). 6. The planting distances of 2 x 2 meters (2500 plants per hectare) was the worst spacing tried. Besides giving a low plant density per unit area it prevents ingress to the planting from any direction. 7. To increase plant density per unit area the closing up of plants within rows is more indicated than closing up the distance between rows. 8. The advantages of the distances of planting between rows of 2.40 or 3.00 meters and 1.20 meters within rows, under present leaf cutting practice, are many. It facilitates weeding, control of suckers growth, and leaf cutting operations.

In spite of the polymorphism of Phormium has long been known, no systematic attempt has been made until now to study comparatively the agricultural value and fiber quality of the varieties. This paper is concerned with preliminary results about leaf yield, fiber-content, und general growth of six varieties, of Phormium tenax Forster including a detailed fiber analysis. It is concluded that the varieties have shown strong differences in plant development and fiber qualities, suggesting that some of them would be much more suitable for the improvement of existing areas, and the establishment of new ones on a commercial basis.

In this paper it is presented a detailed fiber analysis of leaves of twenty mature sisal plants taken from four positions on the plant: 1) first developped leaves (75°); 2) leaves usually cut for fiber extraction (50°) ; 3) leaves adjacent to the central bud (25°) ; and 4) young leaves not yet unfolded from the central bud (0°). The results herein reported are against the prevailing opinion that the sisal leaf only matures after it has unfolded from the central bud. Neither the physical nor the chemical fiber characteristics were adversely affected even if cutting was carried out up to the very young leaves. This practice, however, cannot yet be advised, as it desirability also depends on the effects of the severe cutting upon the subsequent rate of growth of the new leaves. A cutting trial including the cut of all leaves every four months is still in progress. Preliminary results have shown that the plants of this treatment were able to develop eight leaves until the second cut, with an average fiber content of 3,7%.

The present paper deals with the influence of different rates of spacing on the poling of sisal plants (Agave sisalana Perrine). The results were obtained from spacing trials (four randomized blocks of nine treatments) carried out at the Ribeirão Preto and Pindorama Experimental Stations. The percentages of poling plants, up to the 5th leaf cutting, were 20,0% and 91,7% for the narrowest (1,2 x 2,0 m) and widest (2,0 x 3,0 m) spacings tried in Pindorama, while in Ribeirão Preto they were 12,5% and 02,5%, respectivelly. According to these results it may be concluded that the narrow spaced plants were less liable to early poling than the wide spacing ones. The trial at Ribeirão Preto also indicated that among the plants, grown under the same conditions, those producing leaves at a faster rate were the first to pole. At that Station, the yearly average lenf production per plant (for all treatments) up to the 4th leaf cutting, has been 41,5 leaves for those plants poling after 63 months ; 38,0 leaves for those poling after 74 months ; and 35,3 leaves for those plants not poled up to 5 th cutting.

Sisal (Agave sisalana Perrine) growing in various localities of the State of São Paulo is often heavely damaged by "leaf basal necrose", whose symptoms are identical with the "leaf foot disease" reported from Java, East Africa and Belgian Congo. The affected leaves show in the initial stages small spots of black, slightly shrivelled tissue on the lower part of the leaf. These gradually spread out. During the later stages the affected leaves bent over at this point. Only approximately mature leaves of plants between 18 to 30 months old are affected. This disturbance was first observed in Anapolis, Araraquara and Campinas. It was thought to be due to K deficiency in the soil. In order to prove this a small fertilizer experiment was established at Campinas mainly to study the effect of potassium sulfate as a control measure for this "disease". The experiment also included calcium carbonate and control plots, each treatment being replicated three times. The results demonstrated that the trouble can be easily controled by the use ot potassium sulfate applied in the first year of cultivation (two years after planting in the nursery). At all plots not treated with K the typical black spots appeared on the leaves about one year after planting. Considerable damage was caused by this physiological disturbance in all these plots, up to 86,6% of the plants and 15,4% of all leaves being damaged at the three control plots 18 months after planting. The "leaf basal necrose" is until now the single prevalent and destructive "disease" of sisal in the State of São Paulo, where the plant is generally cultivated on K deficient soils. This explains its occurrence in almost all plantations. To avoid this disturbance sisal should be cultivated on rich soils and fertilised with K sulfate if grown on poor ones.