AHLEM MAAROUFI¹

HASSEN ABDELHAFIDH ¹

NOUREDDINE KMICHA²

TAREK AYOUB²

MOHMED ALI TRABELSI².

¹Ecole Supérieure d’Agriculture de Mograne, Université de Carthage. Tunisia.

²Commissariat Régional au Développement Agricole de Zaghouan. Tunisia.

Abstract - Irrigated agriculture has been analysed in Tunisia in recent years because of its high-water consumption and its apparent inefficiency. Several possibilities for water policy have been debated, in particular the pricing of irrigation water. This paper aims to contribute to this discussion by addressing the irrigation water demand and testing the effects of water costs, production value, inputs expenditures, and crop production acreages. Limited surface water supplies, increased pumping costs, and a growing concern over declining groundwater levels are identified as key economic and environmental challenges facing the Nadhour region in Tunisia. The goal of this study is to develop and apply an econometric analysis to examine the expected effect of water price (cost) and others factors on water use. Data area are collected by a survey conducted nearby 140 farmers in the public and private perimeters at Nadhour region in the north of Tunisia. The price elasticity of irrigation water demand and other elasticity were also estimated using Ordinary Least Squares facilitated SPSS.13. main findings show that irrigation water demand is less responsive to water price changes. Thus, the estimated elasticity is -0.655. Results also show that irrigated area and vegetable acreage are the most determinants of water demand. It’s showed too, that water, seeds and mechanization are complementary inputs. The results of this study indicate that the economic value of water used. Based on the findings, this paper recommends that emphasis should be put on effective and efficient use of water in order to improve its productivity. Various water management strategies should be practiced to boost up the water productivity. Furthermore, if possible, restrict crops cultivation to only rainy season by making more effective use of rainfall. Decision maker can apply a seasonal water pricing.

Keywords: Water Demand Elasticity, Water Pricing, Irrigation, Water scarcity, Arid area.

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W. ABDEDAYEM^1,4

S. BEN M’BAREK ^2,4

A. SOUISSI ¹

M. LARIBI^1,4

C. ARAAR^1,4

H. KOUKI⁴

M. FAKHFAKH³

A. YAHYAOUI^4,5

¹National Agronomic Institute of Tunisia (INAT), 43 Avenue Charles Nicole, 1002 Tunis, Tunisia.

²Regional Field Crops Research Center of Beja (CRRGC) BP 350, 9000 Béja, Tunisia

³Comptoir Multiservices Agricoles, 82, Avenue Louis Brailles, Tunis Belvédère, Tunis, Tunisia

⁴CRP Wheat Septoria Precision Phenotyping Platform, Tunis, Tunisia

⁵International Maize and Wheat Improvement Center (CIMMYT) km. 45 Carretera México-Veracruz El Batan, Texcoco, Estado de México, CP 56130

Abstract - Variety mixture, a sustainable disease management approach based on functional diversity, is regaining considerable attention by many research groups studying different pathosystems. In this respect, few studies focused on the wheat-Zymoseptoria tritici pathosystem. Z. tritici, commonly known as the causal agent of Septoria tritici blotch (STB) disease, poses a serious and persistent challenge to durum wheat production where chemical control has become the main control measure available to farmers in Tunisia. In this study, we investigated STB disease progression and the physiological traits behavior during wheat growth stages in two-way mixtures and individual components. Three durum wheat varieties (Monastir, INRAT100 and Karim) with different levels of resistance to STB were assessed in two-way mixtures in various proportions and in four replicates during the cropping season 2018-2019. Disease assessment after heading stage showed that adding 25% or 50% of resistant variety to the susceptible pure stand resulted in a significant disease reduction. However, the efficacy of added 25% of a resistant variety in decreasing the disease seems to be variety dependent. Mixtures with 25% of ‘Monastir’ showed better performance than those with 25% of ‘INRAT100’. Varietal physiological evolution of the canopy showed that STB severity level was negatively correlated to chlorophyll content, normalized difference vegetation index and leaf relative water content. This demonstrates that certain physiological traits can be suitable for screening for resistance to Septoria tritici blotch within-field diversity through the use of variety mixtures.

Keywords: Zymoseptoria tritici, durum wheat, variety mixtures, disease progression, physiological traits, sustainable disease management.

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SONIA MANSOURI¹

TEBER HAJJI²

SANA MEDIMAGH¹

ALI FERCHICHI³

¹Field Crop Laboratory, National Agronomic Research Institute of Tunisia / University of Carthage, Tunisia

² Department of Biology, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunisia

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

Abstract - The aim of this paper was to investigate the fatty acid composition of pearled barley flour by using the GC-MS analysis and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test. Seven (7) Tunisian barley cultivars were initially pearled at 20% (w/w) of grain weight corresponding to the outer layers; the residues (80%, w/w) which correspond to the internal fractions were milled at little particles size of 0.1mm of diameter, and were assessed for their fatty acid content. Results suggest that twenty-six (26) fatty acids were identified and confirmed by GC-MS analysis were found for all cultivars. All extracted fractions have an important feature of high level of linoleic acid (46.16 % for ‘Lemsi’ variety), oleic acid (25.45 % for Rihane variety), palmitic acid and α-linolenic acid (omega 3) methyl esters. These results contribute to enhancing the value of pearled barley flour as a good source of unsaturated and essential fatty acids which serve as functional food ingredients and dietary supplements.

Keywords: Hordeum vulgare, pearling, fatty acids, GC-MS

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Caractérisation de l'élevage caprin en milieux forestiers du Nord-Ouest Tunisien

I. MEKKI¹

S. SMETI¹

O. SLIMENI¹

Y. YAGOUBI¹

F. SADANI²

M. MAHOUACHI³

N. ATTI¹

¹Université de Carthage, INRAT, Labo PAF, Ariana 2049 Tunisie

²Université de Carthage, ESAM, Mateur, Bizerte Tunisie

³Université de Jendouba, ESAK, Le Kef Tunisie

Abstract-In the Tunisian northwest, goat farming faces several constraints (climate hazards, anthropogenic activities, socio-economic changes and crop development). These factors lead to a decline in food resources. The objective of this work, based on a survey of 31 breeders, is to know and understand how farmers in forest regions maintain livestock activity. Principal components analysis resulted in the identification of four livestock systems.

- Sheep-goat breeding in purely forest pasture: These farms are characterized by a mixed goat-sheep breeding with a goat population of 26 heads on average while the sheep herd is only 10 heads. These farms are characterized by a purely forest pasture whose floristic composition is predominantly cork oak.

- Exclusively goat-breeding in alternating pasture: These farms practice alternating grazing, on fallows when the land is not flooded and the forest whose floristic composition based on oak during rainy days.

- Goat breeding associated with cattle farming: Goat and sheep herds of these groups graze only a few rainy days during the winter in the Aleppo pine forest. These herds graze fallows and receive concentrate reserved for cattle herds.

- Multi-active breeding: Breeding on this type of farm is more modern, breeder integrate steaming, flushing, separation of males from females. The breeder in this group apply the supplementation of the kids and sell them at a higher live weight and higher prices than the farms of the other groups.

Key words: system characteristics, forest pasture, goats, mountainous regions

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Etat de la fertilité des sols et de la nutrition minérale du palmier dattier (Variété Deglet Nour) dans la région du Djérid

ZOUGARI-ELWEDI BOUTHEINA^1,2 

SANAA MUSTAPHA²

¹Centre Régional de la Recherche en Agriculture Oasienne (CRRAO), Route de Tozeur Km1, Degache 2260, Tunisie.

²Université de Carthage. Laboratoire des Sciences Horticoles, Institut National Agronomique de Tunisie, 43, Av. Charles Nicole, 1082. Tunis Mahrajène Tunisie.

Abstract - Date palm cultivation (Deglet Nour variety) is one of the most important agricultural activities in the Djerid region (South west of Tunisia). Despite the importance of this activity, average yields of date palms remain low compared to average global yields. Our objectives were therefore to study the state of soil fertility and the mineral nutrition of the date palm.

Our study focused on 9 traditional palm groves, chosen in the Djerid region (Tozeur, Degache and Nefta). For each palm grove, 3 date palms were selected and fertilized by the same amounts of mineral and organic manure to minimize variations in the mineral content of the plant.

Physico-chemical analyzes have shown that the soils of the experimented palm groves have a coarse texture and are characterized by their alkalinity (pH> 7), low availability of organic matter (OM <1%), and low cation exchange capacity (CEC<5.3) and therefore a low chemical reservoir to retain cations. Comparison of the effective contributions with the estimated withdrawals of the year makes it possible to say that the contributions are lower than the calculated levies for nitrogen (N), phosphorus (P), potassium and Calcium (Ca).

These results allow us to hypothesize that there are other factors (climate, cultivation techniques, presence of beneficial microorganisms that naturally exist in the soil, ...) that play an important role in improving soil fertility and mineral nutrition of the date palm.

Keywords: Soil fertility, mineral nutrition, intake, sampling, date palm.

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Caractérisation génétique d’une collection de 16 accessions d’orge (Hordeum vulgare L.) à l’aide des marqueurs moléculaires de type SSR

SALEM MARZOUGUI¹²

¹Pôle Régional de Recherche Développement Agricoles du Nord-Ouest semi-aride à El Kef, Institution de la Recherche et de l'Enseignement Supérieur Agricoles (IRESA), Tunisie

² Laboratoire des grandes cultures, INRAT, Tunisie

Abstract – In barley breeding programs, information on genetic dissimilarity and population structure is very important for the conservation of genetic diversity and therefore the development of new cultivars. This study aimed to assess the genetic variation of Tunisian barley (Hordeum vulgare L.) accessions using SSR-type molecular markers. A total of 30 alleles were detected in 11 SSR markers. The number of alleles per locus ranged from 2 to 4 with an average of 2.7 alleles per locus detected from the 16 barley accessions and the average polymorphic information content (PIC) value was 0.54. Analysis of the population structure with the STRUCTURE software identified 4 subpopulations with allele frequencies ranging from 0.0119 to 0.0597 and a fixation index (Fst) ranging from 0.29 to 0.43. The higher the allelic frequency, the more there is a differentiation between individuals of the same subpopulation. Analysis of the genetic diversity of the barley collection will facilitate cultivar development and efficient use of genetic resources.

Keywords: Barley, Genetic diversity, Molecular Markers, Alleles, Fixation Index

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