H. BEN ZAABZA^1*

A. BEN GARA²

B. JEMMALI²

M. A. FERCHICHI¹

B. REKIK²

¹ Institut National Agronomique 43, Avenue Charles Nicoles 1082-Tunis-Mahrajène Tunisie

² Département des productions animales, Ecole supérieure d’Agriculture de Mateur, 7030, Mateur, Tunisie.

Abstract – A Markov Chain Monte Carlo Bayesian analysis was used on Tunisian dairy cattle data. Data included 14069 lactation records collected from 7139 animals over 16 freshening years from 1997 to 2013. The used model included fixed effects (herd-year, month of calving, and age-parity), a permanent effect, additive genetic effect, and a residual effect. (Co)-variance components were estimated by Bayesian methods. Gibbs Sampling was used to obtain conditional posterior distributions for additive, permanent environmental and residual variances and other genetic parameters. The variance of the residual effects represents the highest average between the three variance components, which is in the vicinity of 1493600 25031, 1833.4 29.391, and 1368.2 22.074, for milk, fat, and protein yields, respectively. Posterior means of heritability were 0.153 0.018, 0.11 0.014, and 0.13 0.016 for the same traits, respectively. Posterior means of repeatability were in the range of 0.342 0.011, 0.252 0.011, and 0.31 0.01 for milk, fat, and protein yields, respectively. The largest genetic correlation (0.94) was observed between milk and protein yields . These results should be useful to implement genetic evaluation for the Tunisian Holstein population. However, results also indicate that there should be additional focus on data recording quality.

Keywords: Markov Chain Monte Carlo, Bayesian Method, Gibbs Sampling, Posterior means, Genetic parameters

K. HAMDI ¹

J. BEN-AMOR ¹

K. MOKRANI ¹

N. MEZGHANNI ²

N. TARCHOUN ¹*

¹ Laboratory of Vegetable crops/ High Agronomic Institute of Chott Mariem, Sousse, Tunisia

² National Genes Bank

Abstract – Tunisia is one of the most important diversity centers for cultivated cucurbits characterized by their adaptation to climatic changes. Many local varieties have resulted from natural or farmers’ selection. The aim of this study was to characterize fifteen local accessions of squash collected from different regions of the country. ‘In situ’ and ‘ex situ’ characterization were undertaken based on 30 parameters related to seeds, growth, flowers and fruit characteristic. This agro-morphological characterization was carried out based on UPOV and IPGRI descriptors. Total sugar, β-carotene pigment, and chemical parameters were also analyzed. Results revealed a considerable genetic variability for most of the agro-morphological parameters. Morphological variation was most apparent in fruit characteristics. In fact, most populations in this study had transverse broad elliptical fruit (75.6%), a medium skin thickness (89.12%), a medium flesh thickness (57.89%) and a big cavity diameter (94.7%). PCA helped to produce a dendrogram which classifies these local varieties into three homogenous groups. Analysis of the biochemical constituents revealed a significant difference between these groups for all the traits, except magnesium content. These results represent the first report on the characterization of squash in Tunisia, which will serve to the management, conservation and use of local genetic resources.

Keywords: squash, local varieties, genetic diversity, characterization.

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R. ENNOURI ¹

S. MILI ^1,2*

¹ Institut National des Sciences et Technologies de la Mer. 28, Rue 2 Mars 1934, 2025 Salammbô, TUNISIA. Tél : 71735848

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

Abstract – In the last decades, marine aquaculture had an important development around the world. In fact, fish farms can generate persistent inorganic elements and nutrients. These element are an essential chemical components of life in the marine environment, but the excessive enrichment, or eutrophication, generate highly undesirable conditions in ecosystem structure and function. The aim of this study was to evaluate the levels of nutrients (Nitrate (NO3, Nitrite (NO2), Ammonium (NH4), Phosphate (PO4), Silicate (Si), Nitrogen (N) in water and Total Organic Carbon (TOC) and Total Nitrogen (TN) in surface sediments from four fish farms (1, 2, 3 and 4) in Hammamet Gulf (Eastern Mediterranean Sea). Measurements and sampling were performed during 2013 at stations inside the farm area and at a reference station (5). Investigated parameters in the water column were nutrient concentrations. Parameters measured in the sediments were total organic carbon and total nitrogen. Nutrients were carried out by Autoanalyzer using the standard colorimetric methods according to Strickland and Parsons (1972). TOC and TN were determined by a CHNS elemental analyzer. The concentration obtained in µmol/l for different element varied between 0.1 and 0.45 for NO2; 0.96 and 2.79 for NO3; 1.75 and 4.07 for NH4; 0.06 and 0.12 for PO4; 1.74 and 4.79 for Si; 11.99 and 13.93 for N and 1.44 and 2.03 for TPO4.  The levels of TOC and TN, from surface sediments below the cages, varied between 2% and 7% and 0.15% and 1.26% respectively. NO2, NO3, PO4 and TPO4 values peaked in water from fish farm1. The highest levels of NH4, Si and N were recorded around fish farm 3. The nutrient level in water column may be related to sources arising from various anthropogenic activities within the study area. Moreover, the spatial variability was due to increasing nutrient concentrations at the localities close to non point sources.

Keywords: Nutrients, fish farms, Gulf of Hammamet

Résumé - Durant ces dernières décennies, l’aquaculture offshore a connu une croissance considérable à travers le monde, ce qui a généré des revenus liés à cette activité et crée des milliers d’emplois directs et indirects. Cependant, les fermes aquacoles peuvent engendrer des rejets de composés chimiques et des nutriments persistants comme les sels nutritifs. Ces derniers sont des éléments essentiels pour la vie des organismes marins, mais un enrichissement intense peut entraîner une eutrophisation du milieu. Dans cette étude nous avons étudié l’impact des fermes aquacoles, implantées dans le golfe de Hammamet (Est de la Méditerranée), à travers l’enrichissement de la colonne d’eau en sels nutritifs (Nitrate (NO3), Nitrite (NO2), Ammonium (NH4), Phosphate (PO4),Phosphore total (PT), Silicium (Si), Azote (N) d’une part et du taux de Carbone Organique Total (COT) et de l’Azote Total (NT) dans les sédiments superficiels d’autre part. L’eau de mer a été collectée durant l’année 2013 à partir des quatre fermes aquacoles (1, 2, 3 et 4) et d’une zone standard (zone témoin : entre les fermes aquacoles).  L’analyse des sels nutritifs a été réalisée à l’aide d’un Autoanalyseur selon la méthode standard colorimétrique (Strickland et Parsons 1972). Le COT et NT ont été déterminés par l’analyseur CHNS. Les valeurs obtenues en µmol/l varient entre 0,1 et 0,45 pour NO2; 0,96 et 2,79 pour NO3 ; 1,75 et 4,07 pour NH4; 0,06 et 0,12 pour PO4; 1,74 et 4,79 pour Si; 11,99 et 13,93 pour N et 1,44 et 2,03 pour TPO4. Les pourcentages du COT et du NT dans les sédiments étudiés varient respectivement entre 2% et 7% et 0,15 % et 1,26 %. Les résultats obtenus montrent que les degrés de NO2, NO3, PO4 et PT présentent un pic pour les échantillons d’eau prélevée au alentour de la ferme 1. Par contre, les teneurs les plus élevées de NH4, Si et N ont été enregistrées au niveau de la ferme 3. Les taux les plus élevés ont été enregistrés au voisinage des fermes relativement anciennes. Cet enrichissement par les sels nutritifs dans la colonne d’eau des quatre fermes étudiées peut être lié à des sources provenant de diverses activités anthropiques dans la zone d'étude et surtout à l’activité aquacole intense dans cette zone.

Mots clés : Sels nutritifs, golfe de Hammamet, fermes aquacoles.

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Caractérisation et typologie des élevages bovins laitiers dans le semi-aride Tunisien (cas de la région de Zaghouan)

M. HAMMAMI¹

R. BOURAOUI¹

H. SELMI²

¹ School of Higher Education in Agriculture, Laboratory of ADIPARA – Mateur, Tunisia

² Institute Sylvo-Pastoral of Tabarka,B.P345 – Tabarka 8110, Tunisia.

Abstract - Faced with an increasing demand for milk and milk products and in an economy open to competition from the external market, the management of livestock systems must undergo a radical transformation in order to optimize the use of All the factors of production in order to ensure a reduction in the cost of production which continues to increase and to guarantee the breeder an acceptable margin. This requires estimating the cost of production and evaluating the performance of dairy farms. It is within this framework that we have conducted this survey among small and medium-sized livestock producers whose objective is to study livestock systems and to have an idea of ​​the profitability of this sector in the governorate of Zaghouan which reflects Conditions and circumstances of breeders throughout the country. The results show that dairy farming makes it possible to obtain an acceptable income for breeders, yet dairy cattle breeding still complains of poor technical and economic performances such as the reproductive and productive poor performance of dairy cows which come first, A lack of experience and training of farmers, particularly in the area of ​​adequate nutrition for cows, which is a real obstacle to the development of the dairy sector.

Keywords: Characterization, dairy cattle breeding, typology, strategy

Résumé - Face à une demande croissante en lait et ses dérivés et dans le cadre d'une économie ouverte à la compétition du marché extérieur, la conduite des systèmes d'élevage doit connaître une transformation profonde dans le sens d'une optimisation de l'utilisation de l'ensemble des facteurs de production afin d'assurer une réduction du coût de production qui ne cesse d'augmenter et garantir à l'éleveur une marge acceptable. Cela exige d'estimer le coût de production et d'évaluer les performances des exploitations laitières. C’est dans ce cadre que nous avons mené cette enquête auprès des petits et moyens éleveurs dont l'objectif est d'étudier les systèmes d'élevage et d'avoir une idée sur la rentabilité de ce secteur dans le gouvernorat de Zaghouan qui reflète les conditions et les circonstances des éleveurs dans tout le pays. Les résultats obtenus montrent que l'élevage laitier permet de procurer des revenus acceptables aux éleveurs, pourtant l'élevage bovin laitier se plaint encore des faibles performances techniques et économiques telles que les mauvaises performances reproductives et productives des vaches laitières qui viennent en premier lieu, un manque d'expérience et de formation des éleveurs, en particulier dans le domaine de la nutrition adéquate pour les vaches, ce qui présente un véritable obstacle au développement de la filière laitière.

Mots clés : Caractérisation, élevage bovin laitier, typologie, stratégie

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A. CHERIF ^*

K. GRISSA-LEBDI

Department of Plant Protection and Post-Harvest Diseases, Laboratory of Entomology-Acarology, National Agronomic Institute of Tunisia, 43 avenue Charles Nicolle, Cité Mahrajène, 1082 Tunis, Tunisia.

Running title: Survey of noctuidae species under Tunisia conditions

Abstract – The male flight activity of the most abundant noctuidae species (Helicoverpa armigera, Spodoptera littoralis, S. exigua and Agrotis segetum) was investigated using sex pheromone delta trap in tomato open field crops. This study was conducted in two Tunisian regions: Zaghouan (Northern half of Tunisia) and Takelsa (North-east of Tunisia) over a three years’ period (2011, 2012 and 2014). The cotton bollworm H. armigera, is considered as the most harmful pest compared to the other species, which can cause several losses. So, development of an appropriate management program is a priority for tomato crop practitioners. This study showed that the four noctuidae species were able to realize up to 5 peaks in the two regions and the tomato of main season was found to be the best for the moth activity than the tomato of late season. For H. armigera, a summer pesticide trial (June, 2014) was conducted by the application of three insecticides in Zaghouan tomato open field plot. The tested insecticides cypermethrin, deltamethrin and H. armigera nucleopolyhedrovirus-based bio-insecticide were significantly effective in reducing the pest population. The bio-insecticide, which may be a new alternative to manage this pest, gave an encouraging result and confirmed the important effect of microbial control agents against lepidopteron species.

Keywords: insecticides, male flight activity, noctuidae species, open field tomato crop, population dynamics.

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Etude des paramètres de performance de trois techniques d’irrigation localisée sous palmiers dattiers dans les oasis de Deguache

L. DHAOUADI ¹

A. BOUGHDIRI ²

I. DAGHARI ³

S. SLIM ²

S. BEN MAACHIA ¹

C. MKADMIC⁴

¹ Regional Research Center for Oasis agriculture of Deguache,Tunisia.

² School of Higher Education of Agriculture in Mateur, Tunisia.

³ National Institute in Agronomy of Tunisia , Carthage University, Tunisia.

⁴ Faculty in Science of Gafsa, Gafsa University,Tunisia

Abstract - The scarcity of irrigation water combined with the effect of climate change and poor management in oases; pose a major threat to the sustainability of the oasis ecosystem. In order to increase the yield of date products while coping with the weather conditions in Tunisia, subsidies were granted to farmers with the aim of practicing water saving techniques and improving the efficiency of use of water, Water in irrigated areas. However, despite these incentives, the productivity of water in irrigation of date palms remains far from predicted. The aim of this work is to identify the best efficient irrigation system under the date palm. It consists mainly of an evaluation of the different irrigation techniques that are currently applied under date palms in the Tunisian oases, namely irrigation by mini diffuser, by bubbling and by underground irrigation. The experiments were carried out within an oasis plot of Deguache. The coefficient of uniformity exceeds 85% for the three localized techniques. The most efficient application of irrigation water was 57% for bubbler irrigation system. The best yield and the best productivity of the water were obtained by the technique of drip irrigation, they were respectively 66 kg / palm and 0.66 kg / m³.

Keywords: Date palm, oasis, localized irrigation, efficiency of application, water use efficiency

Résumé - La rareté des eaux d’irrigation conjuguée à l’effet des changements climatiques et leur mauvaise gestion dans les oasis ; présentent une grande menace pour la durabilité de l’écosystème oasien. Pour augmenter le rendement en produits dattiers tout en faisant face aux aléas climatiques en Tunisie, des subventions ont été accordés aux agriculteurs dans le but de pratiquer des techniques d’économie d’eau et d’améliorer l’efficience d’utilisation de l’eau dans les périmètres irrigués. Toutefois, malgré ces incitations, la productivité de l’eau en irrigation des palmiers dattiers reste loin des prévisions. L’objectif de ce travail est l’identification de la technique d’irrigation la plus efficiente sous le palmier dattier. Il consiste principalement en une évaluation des différentes techniques d’irrigation qui sont actuellement appliquées sous palmier dattier dans les oasis tunisiennes à savoir l’irrigation par mini diffuseur, par barboteur et par l’irrigation souterraine. Les expérimentations ont été menées au sein d’une parcelle oasienne de Deguache. Il s’en sort que le coefficient d’uniformité dépasse 85% pour les trois techniques localisées. La meilleure efficience d’application d’eau d’irrigation (57%), le meilleur rendement et la meilleure efficience ont été obtenus par la technique d’irrigation par barboteur. Ils ont été 66 kg/palmier et 0,66 kg /m³ respectivement.

Mots clés : Palmier dattier, oasis, irrigation localisée, efficience d’application, efficience de l’utilisation de l’eau

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