Ajmi Larbi - Academia.edu (original) (raw)

Papers by Ajmi Larbi

Quelques changements de la composition chimique de la seve du xyleme sous deficience en Fe chez l... more Quelques changements de la composition chimique de la seve du xyleme sous deficience en Fe chez la tomate, le pêcher et l'amandier. Master Thesis. IAMZ, Zaragoza, Spain. Engels C, Marschner H (1992) Adaptation of potassium translocation into the shoot maize (Zea mays L) to shoot demand: Evidence for xylem loading as a regulating step.

JOURNAL OF OASIS AGRICULTURE AND SUSTAINABLE DEVELOPMENT

Olive by-products consisting of 40 % wood pruning and leaves, 40 % Olive pomace and 20 % OMW were... more Olive by-products consisting of 40 % wood pruning and leaves, 40 % Olive pomace and 20 % OMW were ground and combined with preserving them by anaerobic fermentation (wet silage) for 4 months. The pH and total nitrogen/dry matter silage sample were 5.46 and 45 mg/g, respectively; the values comply with standards norms. After the silage process, a decreasing of phenol compound concentration of 67.85% was revealed and among 37 fatty acids compounds were identified with a valuable richness in mineralnutrients. The silage was devoid of total coliforms and fecal coliforms and yeast number doesn't exceed 489.95104 by gram of the silage. Correlation studies were done between the Silage and silage by-products parameters to evaluate the fermentation silage process. They showed different significant trends. A social-economic challenge was studied and discussed. Compared to that of using barley, the cost was 3 times less, with better quality for silage.

Ministry of Higher Education and Scientific Research, 2009

Acta Horticulturae, 2010

The objective of this study was to explore the possibility of using inflorescences instead of lea... more The objective of this study was to explore the possibility of using inflorescences instead of leaves as tree organ to assess the nutritional status in olive orchards. Leaves and inflorescences of olive trees (cv. Arbequina), planted under a high density planting system in two different sites (SE of Tunisia and NE of Spain), were used. The experiment was carried out in two consecutive years, 2006 and 2007. Leaf samples were taken at five different developmental stages: inflorescence emergence, fruit set, pit hardening, fruit development and fruit maturity. Inflorescences were sampled at the stage of white button, when the corolla changes from green to white colour. No significant correlations were found between inflorescence and leaf concentrations of N, P, K, Ca and Mg for each site in both years. However, some significant correlations were obtained between leaf and inflorescence mineral contents in both years when analyzing the full set of data for both locations, although correlations were different in each year. At the pit hardening stage, which coincides with the standard date for leaf sampling, significant correlations between leaves and inflorescence concentrations were obtained only for N (r=-0.827**) in 2006, and for N (r=-0.604*), K (r=-0.527*), P (r=0.760**) and Ca (r=-0.824**) in 2007.

Objective Floral diagnostic has been used for several fruit species (peach, apple, pear and citru... more Objective Floral diagnostic has been used for several fruit species (peach, apple, pear and citrus) offers the possibility of determining the nutritional status of crops and correcting deficiencies if necessary at an earlier stage Material and Methods Arbequina I18" olive trees planted in high density orchards in two sites, Sfax (S.E. Tunisia) and Zaragoza (N.E. Spain), were used. Fifty trees were used in each location. Inflorescences were sampled from trees at the stage of white button (when the corolla changes from green to white) in 2006 and 2007. Inflorescence samples were 10 per site, each obtained collecting materials from 5 different trees. Mature leaves were sampled from the middle portion of non-bearing, current-season shoots, at 5 different developmental stages, both in 2006 and 2007. Leaf samples were taken in the same trees used for inflorescence sampling (10 samples per site and sampling date, each consisting of 20 leaves taken from 5 different trees). Foliar and flower samples were analyzed for macronutrients (N, P, K, Ca and Mg) using standard A.O.A.C. procedures. Statistical analyses were carried out using SPSS for Windows Base 11.0 software (Chicago, IL, USA). Pearson correlations were used to study correlations between macronutrient concentrations in inflorescences and leaves sampled at different stages.

Comunicaciones CONCLUSÕES  O efeito ano, através do clima, representa um factor determinante no ... more Comunicaciones CONCLUSÕES  O efeito ano, através do clima, representa um factor determinante no estado nutricional da casta Baga, ao pintor, ao influenciar significativamente os teores peciolares de N, K, Ca, Mg, B e Zn. O mesmo não parece ser válido para o elemento P, cujos teores, nestas plantas com "vermelhão" se revelaram constantes e sempre no limite mínimo do intervalo adequado adoptado como de referência, independentemente do ano em análise;  O solo condiciona o estado nutricional da casta Baga, ao pintor, de forma significativa para os nutrientes N, Ca, B, Mn e Zn, tendo sido os teores de Ca e B mais elevados, e os de N, Mn e Zn mais baixos, nos solos calcários. Não parece influenciar a alimentação em P, a qual se mostrou no limite mínimo do intervalo adequado adoptado como de referência em ambos os tipos de solo (calcários e não calcários).

Preliminares de la publicacion : Portada, Resumenes, Indice (Obra completa: 120 Pags.- Anejo con ... more Preliminares de la publicacion : Portada, Resumenes, Indice (Obra completa: 120 Pags.- Anejo con Fig.). Thesis submitted for the Degree of Master of Science (Centro Internacional de Altos Estudios Agronomicos Mediterraneos). Tesis Master realizada en la EEAD-CSIC, bajo direccion de los Drs. Javier Abadia y Fermin Morales.

Journal of New Sciences, 2019

Thirteen olive progenies coming from controlled crosses on Tunisian olive cultivars (Meski and Ch... more Thirteen olive progenies coming from controlled crosses on Tunisian olive cultivars (Meski and Chetoui) with autochthones and foreign cultivars were selected among 200 olive genotypes on the basis of their agronomic characteristics in a breeding program initiated in 1994. In this study, weight and flesh to seed ratio, oil content, specific absorption at ultraviolet light, free acid content, chlorophyll and carotenoid contents, total phenols and fatty acid composition of these progenies were determined and compared to their parents. The analysis of variance revealed significant differences among genotypes for all traits (p<0.01) except for UV extinction coefficients (K232 and K270). Some progenies showed superior features compared to their genitors.

1 .pdf (3 Tabls.) copia del poster original presentado por los autores en el Simposio Internacional.

Tunisia is one of the largest olive producers in the world. Its olive production sector plays a s... more Tunisia is one of the largest olive producers in the world. Its olive production sector plays a strategic role in the national economy with its 1.8 million ha under olive representing 34% of the countries agricultural land. However, large portions of these olive orchards are old and poorly maintained. The government of Tunisia initiated in early 2000 a large program for the introduction and expansion of the hyper-intensive olive system in the irrigated area. In 2011, the intensive olive grove areas in Tunisia reached 50,000 ha, with 4,500 ha managed using a super high-density planting (SHD) system (Larbi et al., 2014). However, little information has been provided with regards to an improved technical production package for those wanting to transition to SHD plantations. Among the constraints that farmers are facing during this switch are the nutrient management practices required for SHD plantations. Little research has been conducted on fertilization management in high-density pla...

Journal of Plant Growth Regulation

In some agricultural practices, application of plant growth regulators is very useful as an effic... more In some agricultural practices, application of plant growth regulators is very useful as an efficient means to modulate olive tree vigour to optimize fruit production. However, the physiological mechanisms underlying these effects are still poorly understood. Here, we evaluated the effectiveness of paclobutrazol, chlormequat and prohexadione on the modulation of vegetative growth and fruit set, with a special emphasis on the underlying effects exerted by phytohormones, in one-year-old olive trees (Olea europea cv. Arbosana). Paclobutrazol and chlormequat were tested using both foliar spraying and soil irrigation, while prohexadione was applied by foliar spraying only, and all treatments were compared to a control. Among treatments, paclobutrazol and chlormequat were the most effective in promoting vegetative growth retardation, when applied through foliar spray. Growth retardation by foliar application of paclobutrazol was associated with proline accumulation and reduced gibberellin contents in leaves. Furthermore, hormonal profiling revealed that not only all treatments were effective in reducing the endogenous contents of gibberellins, but also that the entire hormonal profiling was altered upon treatments. It is concluded that (i) various plant growth regulators can be effectively used to control olive tree growth, and (ii) paclobutrazol seems to be more efficient on vegetative growth retardation than the other tested treatments, being foliar application more effective than soil treatment.

Color and pigment analyses are not required by the majority of olive oil marketing standards. How... more Color and pigment analyses are not required by the majority of olive oil marketing standards. However, it is a basic attribute that is highly associated, by most consumers, with the idea of quality. In this study, we aim at providing a fast non-invasive method for routine analysis that can be used on a large scale in the laboratories of olive oil analysis starting from pigment quantification and color range measurements. A selection of 172 virgin olive oil samples obtained in Tunisia between 2018 and 2019 were used for this purpose. Chlorophyll and carotenoid contents were analyzed using a UV spectrophotometer standard method while color range was measured using digital images taken under controlled conditions. All samples showed high significant differences in chlorophyll and carotenoid contents (p <0,01) confirming that the visual selection of the set of samples was satisfactory for this study. Chlorophyll content varied from 3,0 to 28,3 ppm for samples SM137 and SM96 respectiv...