Morphological responses of Rhus tripartitum (Ucria) Grande under water stress

R. ZOUAOUI^1*, Y. AMMARI¹, H. BEN AHMED² , M. ABASSI¹, N. AMIMI¹, A. SMAOUI² , K. HILALI²

¹ National Research Institute of Rural engineering, Water and Forests (INRGREF) (University of Tunis Carthage)

² Faculty of Mathematical, Physical and Natural Sciences of Tunis (University of Tunis El Manar)

Abstract – Water availability is one of the main problems of future climate change. The expected increase in dry days per year for many parts of the world will further aggravate the problem, particularly in the arid and semi-arid zones of the Mediterranean basin. This climate situation can affect floristic biodiversity. For this reason, there has been interest especially Rhus tripartitum (Ucria) Grande, endangered species and belongs to the family Anacardiaceae. It has several interests: medicinal, pharmaceutical, pastoral.The aim of this study is to show the effect of different water regimes on the morphology and growth of seedlings. The plants were grown in a nursery, inside plastic recipients containing sandy soil and were irrigated with water (control T = 100% CC), S1 = 50% CC, S2 = 25% CC and S3 = stop irrigation) under water stress. The statestiques analyzes showed a significant variation (p<0.05) in the effect of the applied stress. Indeed, the results showed that the water deficit resulted in a decrease in the height of the main stem, diameter at the collar, number of leaves and number of branches. In parallel with the previous modifications, an increase in spine number was reported with the increase in stress severity in S3 (stop irrigation). This proves the tolerance of this species to the lack of water.

Keywords: morphology, Rhus tripartitum (Ucria) Grande, tolerance, water stress.

Category: Volume spécial (Conférence CSIEA 2017)
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The risk of agricultural origin pollutants on soil

Le risque lié aux polluants d’origine agricole sur le sol

H. RAHMOUNE^1*, K. GUIMEUR¹, M. HENOUDA¹

¹Université Mohamed Khider, Département d’Agronomie, Biskra – Algérie

Abstract - Agricultural activities are the source of many pollutants scattered in the environment. Metallic trace elements (ETMs), including metals and metalloids, are among those pollutants at risk of priority concern because they are highly toxic and non-degradable. Important pollution for soils and that associated with pollutants from agricultural activities such as fertilizers and pesticides. The objective of our work is to evaluate the toxicity of pesticides and fertilizers by their effects on the abundance of heavy metals (Copper and Zinc) in the soil (in the Biskra region). We did take soil samples at a depth of 30 cm (due to the mobilization of heavy metals in this depth) and the drilling water during on the month of November 2010 and transported to the pedology laboratory of Department of Agronomy of University of Biskra, for the determination of heavy metals (Zn, Cu) by ammonium acetate in the presence of EDTA according to the method of Clement and Françoise (2003). The results show that: there is an increase in copper and zinc levels in treated soils compared to control soils, maximum levels of copper and zinc in treated soils remain far from the toxicity thresholds with a value of 2.80μg / g for Cu and 6.85μg / g for Zn.

Keywords: the risk, pollutants, soil, copper, zinc.

Category: Volume spécial (Conférence CSIEA 2017)
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Study of the behavior of sixteen perennial alfalfa cultivars subjected to two water regimes (ETM and Pluvial) in Mitidja.

Etude du comportement de seize cultivars de luzerne pérenne soumis à deux régimes hydriques (ETM et Pluvial) en Mitidja.

O. OMARI ^1*, I. GHIBECHE¹, M. LAOUAR¹, H.E. KHILIFI¹, A. KHEDIM¹, B. MERABET¹, S. TRIKI¹, A. ABDELGUERFI¹

¹Ecole Nationale Supérieure Agronomique, El Harrach Alger

Abstract - The study consists of a follow-up of the behavior of sixteen perennial alfalfa cultivars, Medicago sativa, subjected to two water regimes (rainfed and irrigated), in a sub-humid climate of the Mediterranean region. Cultivars are of different origins (Americans, Australians, Europeans and Oasis). The results obtained show that the introduced cultivars adapted in an extraordinary way to soil and climatic conditions of the environment, unlike oasis cultivars that seem poorly acclimated to them. The water regime has a very remarkable influence in the yield parameters and the Efficiency of water use of all cultivars.

Keywords: Alfalfa perennial, Medicago sativa, Efficiency of water use

Category: Volume spécial (Conférence CSIEA 2017)
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Organotropism of Mercury in the mullet (Liza ramada) from Lahjar reservoir

Etude de l’organotropisme du Mercure chez le mulet porc (Liza ramada) en provenance du barrage Lahjar

R. ENNOURI^{1 *}, S. MILI², H. LAOUAR³, H. MISSAOUI ¹

¹ Institut National des Sciences et Technologies de la Mer, 28, rue 2 mars 1934 Salammbô, 2025, Tunis, Tunisie.

² Unité de recherche : Exploitation des milieux aquatiques, Institut Supérieur de Pêche et d’Aquaculture de Bizerte, BP 15, 7080 Menzel Jemil, Tunisie.

³ Centre Technique d’Aquaculture, 5, rue du Sahel Montfleury, 1009 Tunis, Tunisie.

Abstract - Lahjar reservoir is located in the governorate of Nabeul. It is characterized by considerable fishery richness. The species exploited in this dam are Mullets (Liza ramada and Mugil cephalus), pikeperch (Sander lucioperca) and carp (Cyprinus Carpio). In recent years, this dam has been exposed to chemical contaminants from nearby agricultural fields through runoff. These contaminants can be accumulated in the superficial sediments and in the fish. This study is the first investigation made in order to estimate the degree of Mercury (Hg) accumulation in three organs (mussels, liver and gills) in Liza ramada from the Lahjar dam. The results of this work showed that the liver accumulates Hg more than gills and mussels. The levels of toxic metal studied in Liza ramada are lower than those found in the same species from other freshwater reservoirs.

Keywords: Lahjar reservoir, Mercury, Liza ramada, organotropism

Category: Volume spécial (Conférence CSIEA 2017)
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Characterization of the small ruminants breeding at the outer-urban of the Rosso region in Mauritania

Caractérisation de l’élevage des petits ruminants dans le péri-urbain de la ville de Rosso en Mauritanie

M. OULD AHMED ^{1, 3}, M. A. OULD MOHAMED

MAHMOUD ^{2, 3}

¹ Département de Production et Santé Animales, Institut Supérieur d’Enseignement Technologique (ISET) de Rosso, Mauritanie

²Département de Production et Protection végétales, Institut Supérieur d’Enseignement Technologique (ISET) de Rosso, Mauritanie

³Unité de Recherche Ressources Génétiques et Environnement (RGE), Institut Supérieur d’Enseignement Technologique (ISET) de Rosso, Mauritanie

Abstract - This study was conducted between May-June 2015 in three villages of the Trarza region of Mauritania. The purpose of this study was to describe the management and to characterize the small ruminants breeding. In the three surveyed villages, the breeders were interviewed according to a questionnaire drafted in French and translated orally into hassanya or poular (national languages) if necessary. A total of 35 small ruminants’ breeders were surveyed. Body measurements and observation were carried out on 401 individuals of sheep (314females and 69 males) and 314 individuals of goat (300 females and 14 males). The results showed that small ruminants breeding is an activity managed by men at 69%. In spite of its socioeconomic importance, it is always associated with others activities. The contribution of this breeding in the family income can exceed in certain cases more than 75 %. Feed resources deﬁciencies and animal health were declared as the main constraints at 90% of the breeders. All the considered physical measurements showed a variation for the various studied sheep and goat populations. At the small ruminants, the color of the dress is very varied present several motives and sometimes difficult to identify. The variability observed by the characters allows envisaging a plan of selection of breeds meeting the needs of breeders.

Keywords: Characterization, breeding practices, morpho-biometry, Small ruminants, Mauritania

Category: Volume spécial (Conférence CSIEA 2017)
Hits: 10422

Threshold-based spraying decision programs for the tomato leafminer, Tuta absoluta on tomato greenhouse

M. BRAHAM¹*, A. BENSALEM¹

¹ LABORATORY OF ENTOMOLOGY AND INSECT ECOLOGY, CENTRE DE RECHERCHE EN HORTICULTURE ET AGRICULTURE BIOLOGIQUE DE CHOTT-MARIEM, UNIVERSITY OF SOUSSE.

Abstract - The tomato leafminer miner, Tuta absoluta (Meyrick) (Lepidoptera, Gelechiidae) is an important insect pest of greenhouse tomatoes, Lycopersicon esculentum in Tunisia. The damages are severe and caused huge economic losses. Because no threshold levels are available for T. absoluta, many growers are applying chemicals at a calendar-based interval in which up to 20 sprays are provided. In order to diminish pesticide applications and to preclude damages to leaves and fruits, the implementation of a threshold level for optimum timing of chemical applications is required. A study was conducted in Saheline region of Tunisia to compare 8 alternative strategies for the control of the tomato leafminer, Tuta absoluta under greenhouse during two tomato cropping seasons in 2010 and 2011. The intervention protocols (strategies) included (1) ST1 = density of 1-4 galleries or larvae per plant , (2) ST2 = density of 5-8 galleries or larvae per plant, (3) ST3 = 9-16 galleries or larvae per plant (4) ST4= superior to 16 galleries or larvae per plant, (5) ST5 =systematically sprayed with chemicals, (6) ST6= systematically sprayed with organic product (spinosad), (7) ST7 unsprayed (control) and (8) ST8 = Sprayed alternatively with conventional chemical and plant extracts. The alternatives were evaluated with (1) the density of T. absoluta biological stages (eggs-pupae) in tomato leaves, (2) the percentage of larval mortality and (3) the fruit quality (the percentage of infested fruits). Results demonstrate the good performance of spinosad (ST6) in the reduction of fruit infestation. There is a difference between ST1, ST2, ST4 and ST5 regarding the larval density suggesting shifting from systematically chemical spray to spraying when population densities reach more than 16 galleries or larvae per plant (ST4). The strategy 8 (combination chemical – organic sprays) seems to be better than Strategy 5 (chemical control only) suggesting the need to integrate plant extracts as soft insecticides in the integrated pest management of the tomato leafminer.

Keywords: Tuta absoluta, tomato greenhouse, threshold level, insecticide sprays, plant extract, Tunisia.

Category: Volume spécial (Conférence CSIEA 2017)
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Study of fish populations in the Sidi Saâd dam by means of multimill nets: application in fisheries management

Étude des peuplements piscicoles dans le barrage de Sidi Saâd moyennant des filets multimailles : application en aménagement des pêcheries

S. MILI^1*, R. ENNOURI², H. LAOUAR³, M.CHHIBI⁴, N. ROMDHANE⁵

¹ Unité de recherche : Exploitation des milieux aquatiques, Institut Supérieur de Pêche et d’Aquaculture de Bizerte, BP 15, 7080 Menzel Jemil, Tunisie.

² Institut National des Sciences et Technologies de la Mer, 28, rue 2 mars 1934 Salammbô, 2025, Tunis, Tunisie.

³ Centre Technique d’Aquaculture, 5, rue du Sahel Montfleury, 1009 Tunis, Tunisie.

⁴ Faculté des Sciences de Bizerte, 7021 Bizerte, Tunisie.

⁵ Direction Générale de la Pêche et de l’Aquaculture, 30, Rue Alain Savary, 1002, Tunisie.

Abstract - The study of fish populations in reservoirs is essential for sustainable management of the freshwater fisheries. The sampling technique used was based on the European standard CEN prEN 14757. This technique (multi-mesh gillnets) was adapted to Tunisian dams. A stratified random sampling was implemented according to the depth and area of the dam. Samplings were conducted in Sidi Saad in April 2015 and April 2016. In 2015, the fish communities were composed by 5 species: roach, rudd, carp, barbell and mullet (Liza ramada) and only carp, barbell and mullet are caught in 2016. The numeric yield was important in 2016 (200 ind / 1000m² net) more than 2015 (113 ind / 1000m² net). Weight yield was high in 2016 (29.9Kg / 1000m² net) and it was around 2015 (18.1Kg /1000m²net). The majority of catches were obtained at depths less than 3m. Populations of freshwater fish in Sidi Saad reservoir show a strong deficit of predatory, forage fish and autochthon fish. This reservoir has a well balanced and abundant population of mullet. Diversity indices indicate a little diversity in this dam. Additionally, in this survey we identified an alarming decrease of the stock of barbell and lack stock of eels. Sidi Saad reservoir required a support from fisheries managers.

Keywords: Fish populations, Sidi Saad reservoir, multi-mesh gillnets, management, fisheries.