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The present study aimed to investigate the efficiency of composted municipal solid wastes (MSWs) to reduce the adverse effects of salinity in two forages species, Polypogon monspeliensis (L.) Desf. and Hordeum vulgare L., and their direct effect on plant hormonal status. Plants were cultivated in the greenhouse using pots filled with saline soil (EC = 5.13 dS m −1 ) supplemented with 100 and 150 t ha −1 of MSW compost or without compost that was used as control, and irrigated twice a week with tap water. Biomass production, leaf number and root length were determined at the end of the experiment. We also analyzed contents of potential toxic (Pb 2+ , Zn 2+ , and Cu 2+ ) elements and seven major plant hormones (abscisic acid, ABA; the cytokinins (CKs) zeatin, Z; and zeatin-riboside, ZR; the auxin indole-3-acetic acid, IAA; jasmonic acid, JA; salicylic acid, SA and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid, ACC) in roots and shoots. The application of MSW compost increased shoot biomass in both species up to 47%, as well as the number of leaves per plant and root length. The increase in root growth was apparent in both P. monspeliensis genotypes than H. vulgare . In general, MSW compost addition decreased ACC concentration in the shoots and roots of studied species. By contrast, CKs substantially increased in shoots especially in both P. monspeliensis genotypes. Auxin indole-3-acetic acid concentration was higher in the shoots of P. monspeliensis from the north region than in H. vulgare and P. monspeliensis derived from the south region. It is suggested that increased CK content and its transport from the root to the shoot were probably induced by the basipetal transport of auxin from the shoot to the roots. This study suggested that the MSW supply at moderate doses (100 t ha −1 ) could be highly beneficial for the cultivation of crops such as P. monspeliensis and H. vulgare in saline soils by adjusting plant hormonal balance.

The olive oil content in phenolic compounds depends on the variety of the fruit used for its extraction as well as on the predominant climate conditions in the tree cultivation area. Here, we report on the characterization of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivars Chemlali and Chetoui, grown in three different Tunisian locations, Zaghouan (North), Sousse (Center) and Sfax (South). Chetoui olive oil samples obtained from fruits of olive trees cultivated in Zaghouan and Chemlali olive oil samples obtained from fruits of olive trees cultivated in Sousse were found to have a higher mean total phenol content (1004 and 330 mg/kg, respectively). Olive oil samples obtained from fruits of both cultivars had different phenolic profiles and a higher content in 3,4-DHPEA-EDA when the olive trees were cultivated in Zaghouan. Both olive cultivars were found to have different responses to environmental conditions. Chetoui olive oil showed decreased oxidative stability when the fruits were obtained from olive trees cultivated in the center of Tunisia (34.8 h) and in Sfax (16.17 h). Furthermore, statistical data showed that the phenolic composition and oxidative stability of Chetoui olive oil varied more by location than those of Chemlali olive oils.

The effectiveness of compost supply at several doses (0, 50, 100, and 150 t/ha) to a saline soil was studied using municipal solid waste (MSW) and palm waste (PW) composts. The experiment was carried out in pots under cultivation of Polypogon monspeliensis (halophyte forage species) and Hordeum vulgare (common forage species) and lasted three months. The investigation focused on some selected soil physico-chemical properties, soil microbial biomass, and ten soil enzymatic activities; Arylsulfatase (ARY), dehydrogenase (DEH), β-glycosidase (β-GLU), protease (PRO), urease (URE), invertase (INV), Fluorescein diacetate hydrolase (FDAH), catalase (CAT), acid and alkaline phosphatases (PHO). Both amendments improve markedly the saline soil quality. They ameliorate the physico-chemical properties. The increase of soil pH is regarded as an interesting fact and is usually proportional to the compost application rate. Electrical conductivity increased proportionally to the applied rates. Soil carbon and nitrogen amounts were also improved and the highest raise (7.5-folds) was noted for carbon. According to the substantial increase of the organic matter, levels of measured microbial biomass and several enzyme activities in saline soil were improved. DEH activity which proposed as a measure of overall microbial activity exhibited a significant increase only at dose 2 (100 t/ha). Consequently, One hundred tones of composts per hectare, under which some enzymes exhibited an optimal of activity and metal accumulation can be minimized, appeared an interesting rate for saline soil amendment.

Chetoui and Chemlali olive fruits were stored at two different temperatures (ambient and 5°C) for different periods before oil extraction at 0, 7, 14, 21 and 28 days to investigate the effect of postharvest fruit storage on olive oil quality. Conventional analyses (acidity, peroxide value, specific extinction coefficient at 232 and 270 nm and fatty acid composition) and non conventional analyses (pigments, total phenols, oxidative stability and radical scavenging capacity) were carried out in order to evaluate the oil quality. Results showed that fruit storage at ambient temperature led to the deterioration of the oil parameter qualities such as acidity, K232 and K270 which is more rapidly in Chemlali oils than that of Chetoui cultivar. In the same way, the trend of total phenols, oxidative stability and radical scavenging capacity of the studied olive oils showed a decrease during the fruit storage at ambient temperature. This reduction was more severe in Chemlali olive oils than those of Chetoui cultivar. Storage of fruits at 5°C prevented the fast alteration that is produced in oils extracted from fruits stored at ambient temperature. Key words: Olive storage, oil quality, fatty acids, stability.

The present study focused on the comparison the chemical composition of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivar (Chemlali) grown in four planting densities (156, 100, 69, and 51 trees ha−1). Despite the variability in the triacylglycerols and volatile compounds composition, the quality indices (free fatty acids, peroxide value, and spectrophotometric indices K232and K270) all of the virgin olive oils samples studied met the commercial standards. Decanal was the major constituent, accounting for about 30% of the whole volatiles. Moreover, the chemical composition of the volatile fraction of the oil from fruits of trees grown at the planting density of 156, 100, and 51 trees ha−1was also characterised by the preeminence of 1-hexanol, while oils from fruits of trees grown at the planting density of 69 trees ha−1had higher content of (E)-2-hexenal (20.3%). Our results confirm that planting density is a crucial parameter that may influence the quality of olive oils.

The aim of the present investigation is to discriminate five minor Tunisian olive cultivars ( Hor Kesra , Sredki , Chladmi , Betsijina and Aloui ) by studying their sterol and phenol compositions. This is the first study of the chemical composition of virgin olive oils (VOO) from these cultivars. The majority of analytical parameters presented statistically significant differences ( P Betsijina oil was characterized by high mean values of total phenols (1400 mg kg −1 ) and oxidative stability (113 h). VOOs studied demonstrate that the differences in phenols (min: 253–max: 1400 mg kg −1 ), tocopherol (139–402 mg kg −1 ), sterols (1039–1567 mg kg −1 ), triterpene dialcohols (19.1–32.4 mg kg −1 ) and triacylglycerols profiles may be explained by genetic factors. Results of PCA and HCA analyses show a good discrimination between varieties according to phenol, triacylglycerol and sterol data. These components seem to be an effective tool to discriminate between the varieties.

In the present work, we studied the effectiveness of the predominant halophytes of Soliman sabkha (Tecticornia indica and Suaeda fruticosa) to promote soil biological activities and ecosystem productivity. Soil Arylsulphatese ARY, beta-glucosidase beta-GLU, phosphatase PHO, invertase INV, urease URE, and dehydogenase DES activities in Extra- and Intra-tuft halophytes and plant productivity were assessed. Results revealed a high increase of microbial community and ARY, beta-GLU, PHO, INV URE and DES activities (+298%, +400%, +800%, +350%, +320%, +25% and +759%, respectively) in Intra-tuft rhizosphere as compared to Extra-tuft one, which is likely due to the significant decrease of salinity in the rhizosphere of Tecticornia indica and Suaeda fruticosa. Both perennial plants exhibited high productivities (7.4 t dry weight ha(-1) and 2.2 t dry weight ha(-1), respectively) and Na+-hyperaccumulating capacities (0.75 t Na+ ha(-1) and 0.22 t Na+ ha(-1), respectively), reducing salt constraint and favouring soil fertility. This constitutes a promising alternative to enhance productivity in such a salt-affected biotope by offering suitable microhabitat for annual glycophytes.