35 research outputs found
Recovery, assessment, and molecular characterization of minor olive genotypes in Tunisia
Olive is one of the oldest cultivated species in the Mediterranean Basin, including Tunisia, where it has a wide diversity, with more than 200 cultivars, of both wild and feral forms. Many minor cultivars are still present in marginal areas of Tunisia, where they are maintained by farmers in small local groves, but they are poorly characterized and evaluated. In order to recover this neglected germplasm, surveys were conducted in different areas, and 31 genotypes were collected, molecularly characterized with 12 nuclear microsatellite (simple sequence repeat (SSR)) markers, and compared with 26 reference cultivars present in the Tunisian National Olive collection. The analysis revealed an overall high genetic diversity of this olive’s germplasm, but also discovered the presence of synonymies and homonymies among the commercialized varieties. The structure analysis showed the presence of different gene pools in the analyzed germplasm. In particular, the marginal germplasm from Ras Jbal and Azmour is characterized by gene pools not present in commercial (Nurseries) varieties, pointing out the very narrow genetic base of the commercialized olive material in Tunisia, and the need to broaden it to avoid the risk of genetic erosion of this species in this country
A Review on the Mechanical Modeling of Composite Manufacturing Processes
© 2016, The Author(s). The increased usage of fiber reinforced polymer composites in load bearing applications requires a detailed understanding of the process induced residual stresses and their effect on the shape distortions. This is utmost necessary in order to have more reliable composite manufacturing since the residual stresses alter the internal stress level of the composite part during the service life and the residual shape distortions may lead to not meeting the desired geometrical tolerances. The occurrence of residual stresses during the manufacturing process inherently contains diverse interactions between the involved physical phenomena mainly related to material flow, heat transfer and polymerization or crystallization. Development of numerical process models is required for virtual design and optimization of the composite manufacturing process which avoids the expensive trial-and-error based approaches. The process models as well as applications focusing on the prediction of residual stresses and shape distortions taking place in composite manufacturing are discussed in this study. The applications on both thermoset and thermoplastic based composites are reviewed in detail
Evaluation of susceptibility of an olive progeny (Picholine x Meski) to olive leaf spot disease caused by Fusicladium oleagineum
Influencia de la densidad de plantación sobre el comportamiento del olivo ‘Arbequina’
The hedgerow orchard type is being increasingly used with the olive although not much information is still available about its suitability to this species. The objective of this study was to assess the influence of planting density (312, 416, 625 and 1,250 trees ha-1) on vigour and productive characteristics of ‘Arbequina’ olive trees planted in 2003. Significant linear regressions have been observed between planting density and tree width, trunk cross section area and canopy volume. Increasing planting density showed positive linear correlation (R2=0.63) with canopy volume per hectare. There was a negative correlation between planting density and production per tree in the five first crops, but it was positive with production per hectare both in olive and olive oil production with coefficients of determination ranging from 0.16 to 0.43 and from 0.28 to 0.46, respectively. A significant linear regression (R2= 0.31 and 0.48) was found between planting density and fruit size on two of the studied cropping years. Our results have not allowed establishing any relationship between planting density and fruit oil content. Finally, the studied densities did not affect the oil fatty acid composition. The production increase observed at the highest tried density is linked to the increase in canopy volume per hectare, but these results should be checked at later stages of tree development, as this study covers only until the fifth harvested crop.El cultivo en seto está siendo cada vez más usado en olivo aunque todavÃa no hay demasiada información acerca de su idoneidad para esta especie. El objetivo de este estudio fue evaluar el efecto de la densidad de plantación (312, 416, 625 y 1.250 árboles ha-1) sobre las caracterÃsticas de vigor y productivas de árboles de ‘Arbequina’ plantados en 2003. Se han observado regresiones significativas entre la densidad de plantación y la anchura del árbol, el área de su sección de tronco y su volumen de copa. La densidad de plantación ha mostrado una relación lineal positiva (R2= 0,63) con el volumen de copa por hectárea. Hubo una correlación negativa entre la densidad de plantación y la producción por árbol de los cinco primeros años, pero fue positiva con la producción por hectárea, tanto de aceituna como de aceite, con coeficientes de determinación que variaron entre 0,16 y 0,43 y entre 0,28 y 0,46, respectivamente. Se encontró una regresión significativa (R2= 0,31 y 0,48) entre la densidad de plantación y el tamaño de los frutos en dos de las cosechas estudiadas. Nuestros resultados no han permitido establecer ninguna relación entre la densidad de plantación y el contenido en aceite del fruto. Finalmente, las densidades de plantación empleadas no afectaron a la composición acÃdica del aceite. El aumento de producción observado a las mayores densidades de plantación está asociado al incremento de volumen de copa por hectárea, pero estos resultados deben ser confirmados con árboles de mayor desarrollo, puesto que este estudio solo llega hasta la quinta cosecha recolectada
Adaptación de cultivares de olivo a plantaciones de alta densidad
A new olive orchard type, based on high-density planting, was introduced in Tunisia in 2000 by some investors, using mainly ‘Arbequina’, the most utilized cultivar up to that time in Spain and in some other countries. Limited cultivar choice is in fact considered one of the main inconvenients for using high planting densities in olive. Therefore, a comparative trial was set up in 2003 to evaluate the suitability of four olive cultivars (‘Arbosana’, ‘Arbequina i-18’, ‘Chemlali’ and ‘Chetoui’) to a planting density of 1250 trees ha–1. The results showed that the local cultivars ‘Chemlali’ and ‘Chetoui’ were more vigorous than ‘Arbosana’. However, ‘Arbosana’ and ‘Arbequina i-18’ presented the highest fruit yield in comparison to the local ones. Furthermore, ‘Arbosana’ showed the highest accumulated fruit yield after the first five harvests and the highest crop efficiency (0.56-1.52 kg m–3 of tree canopy). Also, ‘Arbosana’ and ‘Arbequina i-18’ presented the lowest alternate bearing indexes (0.38 and 0.44, respectively) during that period of time. Significant differences among cultivars for oil content and fatty acid composition were observed. The oleic acid content was high in ‘Arbosana’ and ‘Chetoui’ (69.4-66.7%) and intermediate to low in ‘Arbequina-i18’ and ‘Chemlali’ (64.9-56.1%). The high vigour and low production of the studied Tunisian cultivars show that it is not advisable to use them in high-density orchards. ‘Arbosana’ was the most adapted cultivar to this new planting density system in this trial.Un nuevo tipo de olivar, en alta densidad, fue introducido en Túnez en el año 2000. El cultivar estándar en estas plantaciones fue ‘Arbequina’, el más utilizado hasta ese momento en España y otros países. Una de las principales limitaciones para el uso de altas densidades de cultivo en olivo es la escasa disponibilidad de cultivares de bajo vigor. Por ello, se estableció un ensayo en 2003 para evaluar la adaptación de cuatro cultivares (‘Arbosana’, ‘Arbequina i-18’, ‘Chemlali’ y ‘Chetoui’) a una densidad de plantación de 1250 árboles ha–1. Los resultados obtenidos mostraron que los cultivares tunecinos ‘Chemlali’ y ‘Chetoui’ son más vigorosos que ‘Arbosana’. Sin embargo, ‘Arbosana’ y ‘Arbequina i-18’ presentaron la mayor producción de aceitunas en comparación con los tunecinos. ‘Arbosana’ mostró la mayor producción acumulada de aceitunas después de las primeras cinco cosechas y la mayor eficiencia productiva (0,56-1,52 kg m–3 de copa). Además, ‘Arbosana’ y ‘Arbequina i-18’ presentaron los menores índices de alternancia (0,38 and 0,44, respectivamente) durante ese período de tiempo. Se observaron también diferencias significativas entre los cultivares estudiados con respeto al contenido y la composición acídica de aceite. El contenido en ácido oleico fue alto en ‘Arbosana’ y ‘Chetoui’ (69,4-66,7%) e intermedio-bajo en ‘Arbequina i-18’ y ‘Chemlali’ (64,9-56,1%). El alto vigor y baja producción de los cultivares tunecinos estudiados muestran que no es recomendable utilizarlos en plantaciones de alta densidad. ‘Arbosana’ ha sido el cultivar mejor adaptado a la densidad de plantación utilizada en este ensayo
Effect of foliar Boron application on growth, phenology, yield and oil quality of olive trees (cv. Arbequina) conducted under a high density planting system
1 .pdf (3 Tabls.) copia del póster original presentado por los autores en el Simposio Internacional.Foliar boron fertilization is commonly used in intensive olive orchards
without knowledge about the efficiency of this fertilization on olive
production.Peer reviewe
Experimental and numerical investigation on the residual distortion and stress fields in un-symmetric hybrid composite laminates induced by the manufacturing process
Olive cultivars suitability for high-density orchards
A new olive orchard type, based on high-density planting, was introduced in Tunisia in 2000 by some investors, using mainly �Arbequina�, the most utilized cultivar up to that time in Spain and in some other countries. Limited cultivar choice is in fact considered one of the main inconvenients for using high planting densities in olive. Therefore, a comparative trial was set up in 2003 to evaluate the suitability of four olive cultivars (�Arbosana�, �Arbequina i-18�, �Chemlali� and �Chetoui�) to a planting density of 1250 trees ha�1. The results showed that the local cultivars �Chemlali� and �Chetoui� were more vigorous than �Arbosana�. However, �Arbosana� and �Arbequina i-18� presented the highest fruit yield in comparison to the local ones. Furthermore, �Arbosana� showed the highest accumulated fruit yield after the first five harvests and the highest crop efficiency (0.56-1.52 kg m�3 of tree canopy). Also, �Arbosana� and �Arbequina i-18� presented the lowest alternate bearing indexes (0.38 and 0.44, respectively) during that period of time. Significant differences among cultivars for oil content and fatty acid composition were observed. The oleic acid content was high in �Arbosana� and �Chetoui� (69.4-66.7%) and intermediate to low in �Arbequina-i18� and �Chemlali� (64.9-56.1%). The high vigour and low production of the studied Tunisian cultivars show that it is not advisable to use them in high-density orchards. �Arbosana� was the most adapted cultivar to this new planting density system in this trial
Planting density affects vigour and production of �Arbequina� olive
The hedgerow orchard type is being increasingly used with the olive although not much information is still available about its suitability to this species. The objective of this study was to assess the influence of planting density (312, 416, 625 and 1,250 trees ha-1) on vigour and productive characteristics of �Arbequina� olive trees planted in 2003. Significant linear regressions have been observed between planting density and tree width, trunk cross section area and canopy volume. Increasing planting density showed positive linear correlation (R2=0.63) with canopy volume per hectare. There was a negative correlation between planting density and production per tree in the five first crops, but it was positive with production per hectare both in olive and olive oil production with coefficients of determination ranging from 0.16 to 0.43 and from 0.28 to 0.46, respectively. A significant linear regression (R2= 0.31 and 0.48) was found between planting density and fruit size on two of the studied cropping years. Our results have not allowed establishing any relationship between planting density and fruit oil content. Finally, the studied densities did not affect the oil fatty acid composition. The production increase observed at the highest tried density is linked to the increase in canopy volume per hectare, but these results should be checked at later stages of tree development, as this study covers only until the fifth harvested crop
The possibility of using inflorescence analysis to evaluate the nutritional status of olive trees
1 .pdf (2 Tabls.) copia del Póster original presentado por los autores. Se acompaña de 1 .pdf copia del resumen oficial.The main objective of this work was to evaluate if inflorescence analysis can be considered as an alternative to foliar diagnosis in determining the nutritional status of olive orchards. Olive leaves from cv. Arbequina, planted under high density planting system in two different sites (Tunisia and Spain), were sampled at 5 developmental stages (inflorescence emergence, fruit set, pit hardening, fruit development and fruit maturity) during two years, 2006 and 2007.This study was supported by AECI-MAE projects A/3005/05 and A/5 199/06.Peer reviewe