Phytochemical Screening and Assessment of The Antioxidant Activity of Bio-phenols of Olive Oil Mill Wastewater From The Cold Extraction of Olive Oil in Khenchela Region Eastern of Algeria

The objective of this study was to evaluate in vitro the antioxidant activity of polyphenols from olive oil mill wastewater in Khenchela region eastern of Algeria after conducting a phytochemical screening. The extraction of polyphenols was done by the maceration method. The quantitative estimate of the total polyphenols and flavonoids was evaluated by the colorimetric method. Antioxidant activity was evaluated in vitro using three tests DPPH, ABTS and FRAP and ascorbic acid as a reference antioxidant. The results obtained showed that the phytochemical screening carried out allowed us to highlight the presence of polyphenols, flavonoids, tannins and reducing sugars with large quantities, sterols and terpenoids in lesser amounts. The values of total polyphenols and flavonoids were sequential: (925.8 8.1 g GAE/mL) and (45.97 9.5 g QE /mL). The values of the antioxidant activity obtained from the three tests DPPH, ABTS, and FRAP were successively the followings: (IC50: 144.52 1 g/mL), (IC50: 169.6 35.3 g/mL) and (IC50: 248.13 10.1 g/mL). At the end of this study, it appears that OMW polyphenolic extract has an important antioxidant power

Deficit Irrigation Using Saline Water of Fruit Trees under Water Scarcity Conditions of Southern Tunisia

Both water scarcity and salinity are major obstacles for crop production in arid parts of Tunisia and require adoption of strategies aimed at improving water-use efficiency. Field experiments on deficit irrigation (DI) of table olive, orange trees, and grapevines with saline water (2 dS m  1) were conducted in the arid region of M denine, Tunisia. Three irrigation treatments were compared with the farmer’s method (FM) over two years (2013–2014): deficit irrigation (DI75) and (DI50), which received 75% and 50% less water than full irrigation (FI), respectively, and full compensation of the crop evapotranspiration (FI). Measurements included seasonal changes in soil water content, soil salinity, yield, fruit quality, and economic return. Results showed that in-season water limitations, roughly between 700–250 mm, caused significant reductions in yield and fruit weight, but improved the total soluble solids of fruits. Under FI, DI75, DI50, and FM, average yields were 26.6, 20.1, 14.7, and 21.2 t ha  1 for orange, 4.5, 4.0, 3.1, and 3.5 t ha  1 for table olive, and 3.8, 3.4, 3.1, and 3.5 t ha  1 for grapevine, respectively. Soil salinity build up increased linearly with decreasing irrigation water. Irrigation water productivity (IWP), although lowest for FM, was relatively high (3.30–4.30 kg m  3 for orange, 0.65–1.20 kg m  3 for table olive, and 0.74–1.30 kg m  3 for grapevine). Economic evaluation showed that the FI strategy generated the greatest net income (1800–6630 USD ha  1), followed by DI75 (1350–3940 USD ha  1), FM (844–4340 USD ha  1), and DI50 (600–2400 USD ha  1). The results show an important potential for reasonably sustaining farmer’s income under increased water scarcity

Etude de l’effet de l’irrigation avec des eaux magnétisées sur la croissance, le rendement du piment et la salinisation du sol dans un environnement aride

Le présent travail concerne la gestion des eaux salées en irrigation de la culture de piment à travers le pratique de pilotage d’irrigation et l’utilisation de technique de magnétisation afin de réduire les risques de dégradation du sol et d’améliorer la productivité de culture. A cet effet, une expérimentation a été menée dans une parcelle expérimentale située dans la région de Médenine, Tunisie. La culture du piment variété Baklouti a été transplanté sur un sol sableux et irriguée au goutte à goutte avec des eaux ayant une salinité de 7,3 dS/m. Trois traitements d’irrigation ont considérés. Deux traitements magnétiques consistent à traiter l’eau salée par un champ magnétique en utilisant deux magnétiseurs Delta-Water (DW) et Magiko. Dans le troisième traitement (Témoin), l’eau n’a pas été traitée. Les mesures effectuées ont porté sur l’humidité et la salinité du sol, l’indice foliaire (LAI), le poids frais, et la teneur relative en eau durant le cycle de développement de la culture. A la récolte, le rendement et ses composantes (nombre des fruits /plante, poids de fruits/plante) ont été évalués. Les résultats montrent que le pilotage d’irrigation adapté aux conditions réelles maintient l’humidité du sol proche à la capacité au champ pour les trois traitements. Par ailleurs, le pilotage adopté et les quantités des pluies reçues ont permis de réduire la salinité du sol. Les traitements magnétiques améliorent la croissance de la culture avec l’augmentation de l’indice foliaire. L’augmentation de la croissance est due à une amélioration significative de la teneur relative en eau de la culture. Ces techniques résultent, également, en une augmentation du rendement (20 et 22.4 t/ha) et ses composants et une amélioration du calibre des fruits qui atteint 10.3 g pour les plantes traitées par Magiko comparé à 8.8 et 8.3 g, respectivement, pour DW et témoin. Ainsi, l’utilisation du traitement magnétique de l’eau en agriculture pourrait constituer une technique prometteuse dans la valorisation des eaux salées qui reste à confirmer par des expérimentations à long terme et dans différentes condition

Saline water use for vegetable crops production in smallholders farms

Field studies on saline water use (6 dS/m) for carrot, lettuce and pepper production in smallholder's farms were conducted in the arid region of Medenine-Tunisia. The irrigation regimes were full (FI) and deficit (DI-80, DI-60, FI-DI60) irrigated with levels of 100, 80 and 60% of ETc when 40% of total available water in the root zone in the FI treatment was depleted, and farmer method (Farmers). Results show that the greatest values of soil salinity were observed under farmer and DI-60 treatments. Relatively low ECe values were also recorded under FI-DI60 and DI-80 treatments. The highest mean yields of carrot (26.8-28.7-29.5 t/ha), lettuce (42.6-45.8 t/ha) and pepper (22.3-24.4 t/ha) were recorded for the FI treatment who is not significantly different with the FI-DI60 and DI-80 treatments. Compared with FI100, significant reductions in carrot, lettuce and pepper yields were observed under the DI60 and farmers treatments resulting from a reduction in yield components. The farmer’s method increased soil salinity and resulted in an increase of water use of 43-57% for carrot, 26-29% for lettuce and 11.5-16% for pepper. Water productivity (WP) values reflected the differences in yields and varied between 3.4 (Farmers) and 9.7 kg/m3 (DI-80) for carrot, 7.5 and 19.1 kg/m3 for lettuce and 2.4 and 5.5 kg/m3 for pepper across different years and treatments. The soil water balance-based irrigation method (FI) generated the greatest net income compared to the Farmers treatment in carrot, lettuce and pepper productions under arid environment and the lowest soil salinization. FI scheduling technique is suggested for optimizing saline water use for vegetable crops. Under water scarcity, the adoption of the FI-DI60 and DI-80 strategies results in 4.5 to 20% water savings as compared to FI with small impact on salinity in the root zone and yield and net income reductions

Literature review on Water Productivity of date palm trees in Tunisian agro systems

The sustainability of agricultural productivity is closely related to the optimal exploitation of natural resources, namely the efficient water resources management.  The evaluation of the effectiveness of the adopted strategies and the applied practices and systems relies on a number of criteria and parameters of which water productivity indices represent the most relevant criteria. In this context, the present study aims to assess the water productivity for date palm cultivation in Tunisia based on an accurate literature review of the previously published scientific papers and reports related to the different studies carried out in these agro-oases regions of the country for the evaluation of the different indices of water productivity. This review represents the main baseline document highlighting in an exhaustive way the challenging features related to water productivity for date palm agro-systems. The outcome of this review indicates that (i) the cultivated date surface is  expanding, covering more than 58.000 ha with a total production of 355.000 tons in 2021(ii) the distribution of irrigation water is variable and irregular. iii) The reported water supply  for date palm range from 20,000 to 30,000 m3/ha while a number of scientific-based calculations estimate the crop water requirements for regular date palm production is  between 10,000 and 18,000 m3/ha (iv) the efficiency of water conservation techniques is related to numerous in farm factors related to the old traditional surface irrigation systems, to the soil salinization, alkalization and  permeability  loss and to the overexploitation issues of water resources that reaching is growing and may impact the productivity of date palms and sustainability of the production system (v) the estimation of the biophysical water productivity based on the reported data reaching barely  0.66kg/m3. This overview highlights the need for an accurate evaluation of the ecological efficiency of the used management measures to a clear appreciation of the  new strategies and policies to face the current constraints with regard to all different driving forces influencing water productivity both at the macro and micro scale

Influence of Water Stress on Growth, Chlorophyll Contents and Solute Accumulation in Three Accessions of <em>Vicia faba</em> L. from Tunisian Arid Region

In this study, we aim to investigate the physiological and biochemical adaptations of Vicia faba plants to moderate irrigation regime (T1) and describe the effects of water stress on their growth performance and chlorophyll contents. For this reason, three Tunisia accessions (ElHamma, Mareth and Medenine) were studied. An experiment was conducted for one month. Faba bean plants were first grown in a greenhouse and then, exposed to water stress, whereby they were irrigated up to the field capacity (FC) of 0% (control, T0) and 50% of the control (moderate stress, T1). The effect of water stress on physiological parameters showed differences in relation to the accessions studied and the water regime. Relative water content (RWC) of ElHamma accession does not seem to be affected by stress as compared with the control regime. Total chlorophyll content decreases, whereas soluble sugar contents increases for all accessions studied. ElHamma has the highest content. About morphological parameters, bean growth varies according to the ascension and treatment. Hydric stress impedes the growth of the root part and caused a significant reduction in the shoot and root Dry Weight (DW) of the T1-stressed beans, compared to the optimal irrigation (T0)

Assessment of the physio-biochemical performance of Tunisian barley landraces under deficit saline-irrigation during grain filling stage

Salinity is one of the main and important abiotic stresses that adversely affects crop growth, development and production. In this study, two barley (Hordeum vulgare L.) landraces were subjected to three treatments of deficit saline-irrigation (12 dS/cm) (T0 = 100%ETc, T1 = 75%ETc, and T2 = 50%ETc) during grain filling stage. Carbon isotope discrimination (Δ13C) was associated with some physio-biochemical parameters to evaluate barley response to saline conditions. Results of this study showed that deficit saline-irrigation significantly (p < 0.05) decreases Δ13C in both barley landraces. Moreover, photosynthetic rate (A), transpiration (E), stomatal conductance (gs), and instantaneous water use efficiency (iWUE) were significantly affected by treatments. Relative water content (RWC), chlorophyll a, and chlorophyll (SPAD) value were significantly (p < 0.01 and p < 0.001) were affected by deficit saline-irrigation. In addition, phenolic compounds were affected by treatments and landraces (except syringic and p-coumaric acids), and their interactions (except syringic acid). Moreover, high correlations were noticed between Δ13C and physio-biochemical parameters. Results suggested that both barley landraces make a higher iWUE, and a weak variation in phenolic compounds. Moreover, Δ13C associated with physio-biochemical traits can also be good criteria for screening of salt-tolerance of barley during grain filling stage. Taken together, our study suggests that the response to deficit saline-irrigation in barley landraces involves an interplay between various physiological and biochemical mechanisms mainly related to Δ13C

Zinc oxide nanoparticles enhances germination performance of wheat (Triticum durum L.) seeds under individual and combined salinity and copper treatments

In oasis areas, with the depletion of fresh water resources and the use of underground water and industrial wastewater for irrigation, agriculture is under the cumulative harmful effects of multiple abiotic factors such as salinity and heavy metals. Under these conditions, a new strategy to improve crop production is urgently required. Here, we evaluate the potential of zinc oxide nanoparticles (ZnO-NPs) (0, 50 mg/L) to attenuate single and interactive effects of 10-days exposure to salinity (0, 50 mM NaCl) and copper (0, 50 mg/L CuSO4) treatments on the germination performance of wheat (Triticum durum L. Desf., ‘Chili’) seeds. Results showed that, in the absence of ZnO-NPs, exposure to salinity or copper alones significantly (P < 0.05) inhibits the germination process. The combined exposure to salinity and copper, aggravates the inhibitory effects on seeds germination. In contrast, addition of ZnO-NPs significantly improved wheat germination in control conditions, and attenuates the harmful effects of single and combined NaCl and CuSO4. The potential mechanism of the preventive effect of ZnO-NPs might involve a competitive replacement of Cu2+ accumulation by which of Zn2+. It is concluded that ZnO-NPs improves the germination of wheat seeds in oasian lands suffering from hypersalinity and copper soil’s accumulation, thus ameliorates their productivity

Impact of Deficit Irrigation Strategies Using Saline Water on Soil and Peach Tree Yield in an Arid Region of Tunisia

Sustainable fruit orchard development in arid areas is severely affected by the scarcity of fresh water. To mitigate the lack of fresh water, the use of low-quality water for irrigation is becoming a common practice in several margin areas. However, salinity is considered one of the most important environmental constraints limiting the successful crop production. Therefore, the effects of deficit irrigation strategies using saline water (3.1 dS m−1) on soil water content, soil salinity, and yield of commercial peach orchard were investigated. Three irrigation treatments were considered: a Control, full irrigated (FI); and partial root-zone drying (PRD50); and deficit irrigation (DI) strategies irrigated at 50% ETc. These levels of water supply allowed for contrasting watering conditions with clear distinction between irrigation treatments. The differential pattern in soil moisture was accompanied by that of soil salinity with an increase in all FI treatments (16–25%). The results indicated that soil salinity increased with increasing water supply and evaporative demand during the growing season from January (3.2 dS m−1) to August (6.6 dS m−1). Deficit irrigation strategies (DI, PRD50) induced more soil salinity along the row emitter compared to the Control due to insufficient leaching fractions. By the end of the growing season, the soil salinity under long-term saline drip irrigation remained stable (5.3–5.7 dS m−1). An efficient leaching action seemed to be guaranteed by rainfall and facilitated by sandy soil texture, as well as the high evaporative demand and the important salt quantity supplied, which maintain the deficit irrigation strategies as valuable tools for water saving and improving water productivity. The significant water saving of 50% of water requirements induced a fruit yield loss of 20%. For this reason, DI and PRD50 could be reasonable irrigation management tools for saving water and controlling soil salinity in arid areas and on deep sandy soil.The study was supported by Research Agreement Program of Dry Land and Oasis Cropping Laboratory at Arid Regions Institute funded by the Ministry of Higher Education and Scientific Research Tunisia.info:eu-repo/semantics/publishedVersio

Zinc oxide nanoparticles enhances germination performance of wheat (Triticum durum L.) seeds under individual and combined salinity and copper treatments

In oasis areas, with the depletion of fresh water resources and the use of underground water and industrial wastewater for irrigation, agriculture is under the cumulative harmful effects of multiple abiotic factors such as salinity and heavy metals. Under these conditions, a new strategy to improve crop production is urgently required. Here, we evaluate the potential of zinc oxide nanoparticles (ZnO-NPs) (0, 50 mg/L) to attenuate single and interactive effects of 10-days exposure to salinity (0, 50 mM NaCl) and copper (0, 50 mg/L CuSO4) treatments on the germination performance of wheat (Triticum durum L. Desf., ‘Chili’) seeds. Results showed that, in the absence of ZnO-NPs, exposure to salinity or copper alones significantly (P < 0.05) inhibits the germination process. The combined exposure to salinity and copper, aggravates the inhibitory effects on seeds germination. In contrast, addition of ZnO-NPs significantly improved wheat germination in control conditions, and attenuates the harmful effects of single and combined NaCl and CuSO4. The potential mechanism of the preventive effect of ZnO-NPs might involve a competitive replacement of Cu2+ accumulation by which of Zn2+. It is concluded that ZnO-NPs improves the germination of wheat seeds in oasian lands suffering from hypersalinity and copper soil’s accumulation, thus ameliorates their productivity