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Organic matter water extract, or so-called ‘tea’, may be used to correct nutrient deficiencies in crops or enhance their defense systems. Such tea mixtures are prepared locally by Mediterranean farmers to offset a multitude of constraints, particularly a scarcity of organic manure or high synthetic input costs. However, the diverse range of tea production and usage practices and farmers' underlying rationales have yet to be thoroughly studied. Yet locally they constitute real alternatives that allow farmers to maintain their income levels while reducing reliance on chemical inputs. The main objective of this study was to gain insight into farmers' rationale and practices regarding the production of homemade dry manure tea (HMT) in North Africa, while also highlighting the benefits perceived by farmers. Nearly 50 interviews with farmers were thus conducted in three irrigated cropping areas in Morocco, Algeria and Tunisia. Our results showed that HMT is widely used in intensified family horticultural cropping systems that usually rely on drip irrigation and chemical fertilization. The analysis of farmers' practices revealed that HMT was generally made from aged manure that was pure or consisted of a mixture of sheep, cow or poultry dung. The production protocol varied in terms of drenching techniques, maceration time, container volume and type, and filtration techniques. Farmers applied the derived tea via the drip irrigation system, regularly or with a limited number of applications. The analysis of farmers' rationales and perceptions regarding HMT clearly highlighted that they felt that these practices played a positive role. HMT was considered to improve vegetative growth, yield and, to a lesser extent, soil properties. These benefits could in turn lead to decreased use of synthetic fertilizers by farmers, while boosting their income. The increased understanding of HMT and the underlying rationales showcased in this study could help scientists better analyze and assess these practices in the future. The findings could also facilitate improvement and wider dissemination of these practices to achieve more sustainable irrigation systems in the intensified irrigated cropping areas that abound in North Africa.

28 Pags.- 1 Fig.- 3 Tabls. The definitive version is available at: https://www.tandfonline.com/toc/lpla20/current, Recent trends in peach orchards have focused on intensification and high density plantings using different Prunus rootstock species with different vigor traits. This investigation aims to study the physiological behavior of different Prunus rootstocks in order to identify the most suitable rootstock under warm Mediterranean conditions. Field agronomic performance and foliar nutrient content of the flat peach cultivar ‘Subirana’ grafted on ten different Prunus rootstocks were studied on calcareous soil typical of the Mediterranean area. Ten rootstocks: ‘ADAGAF 04-03’, ‘AGAF 0301-04’, ‘Garnem’, ‘Krymsk® 1’, ‘Krymsk® 86’, ‘PAC 847’, ‘PADAC 04-01’, ‘PADAC 150’, ‘PM 105 AD’, and ‘Rootpac® 70’, were considered. Vegetative growth, chlorophyll SPAD index, leaf mineral status and deviation from the optimum percentage (DOP) index were determined. Leaf chlorophyll content varied depending on the rootstock. ‘PADAC 04-01’ and ‘ADAGAF 04-03’ showed higher chlorophyll index. The lowest SPAD values were observed for the most dwarfing rootstock ‘Krymsk® 1’, which showed visual chlorosis symptoms, and lower leaf mineral contents compared to the other rootstocks. Peach trees on Prunus rootstocks showed differences in leaf macronutrient and micronutrient content. ‘Rootpac® 70’, ‘ADAGAF 04-03’ and ‘PADAC 04-01’ had better adaptation under warm Tunisian conditions but high ΣDOP index. The most invigorating ‘Garnem’ had the highest imbalanced nutritional status, but continues to perform well under warm conditions. Interesting results were obtained with ‘Rootpac® 70’ showing one of the best balanced nutritional values (average ΣDOP index). However, the most dwarfing rootstock ‘Krymsk® 1’ presented the worst adaptation to the studied warm Mediterranean conditions., This research was supported by the Tunisian Ministry of Higher Education and Scientific Research (LR17AGR01, LR16IO02) and by the Bi-lateral Cooperation Project between Tunisia and Spain ‘Compatibilité des porte-greffes Prunus avec les espèces fruitières à noyau’ (Ref. A/5525/06) funded by the Agencia Española de Cooperación Internacional (AECI).

Introduction. Recent management trends in almond orchards have focused on intensification and high-density plantings using Prunus rootstock cultivars with different vigor traits. This investigation aims to prospect precocious detection of adequate scion-rootstock combination for almond. Materials and methods. Five almond cultivars (‘Tuono’, ‘Lauranne’, ‘Soleta’, ‘Belona’ and ‘Guara’) grafted on three peach and plum based rootstocks of different degrees of vigor (‘Garnem’, ‘Rootpac-40’ and ‘Rootpac-20’) were trained in super high-density planting in an experimental orchard. Tree vigor, tree water status, leaf chlorophyll content and quantum yield of photosynthesis system II (PSII) were monitored over two budding seasons. Results and discussion. ‘Garnem’ and ‘Rootpac-40’ were respectively the most and the medium vigorous rootstocks and induced the best tree water status, chlorophyll content and quantum yield of PSII for the tested almond cultivars. Scions grafted on ‘Garnem’ had the highest values of trunk cross-sectional area (TCSA), and almond scions were higher on ‘Garnem’, intermediate on ‘Rootpac-40’ and lower on ‘Rootpac-20’. Scions grafted on ‘Rootpac-20’ seemed to be the most dwarf phenotype. Moreover, ‘Rootpac-20’ performed the lowest values of stem water potential and showed various visual symptoms of chlorosis. Conclusion. Overall, ‘Rootpac-40’ exhibited a medium capacity to control tree vigor and well adapted to Mediterranean soil conditions.

Tolerance to water deficit in diploid (2x) and doubled diploid (4x) ‘Carrizo citrange’ (Citrus sinensis [L.] Osbeck × Poncirus trifoliata [L.] Raf) was investigated. Water deficit was applied for 4 weeks. Physiological parameters, including stomatal conductance (g s), photosynthesis (A), transpiration (E), leaf and soil water potentials (Ψ leaf; Ψ soil), and pot water loss, were monitored throughout the stress. Moreover, ABA, H2O2 contents, and the expression of genes involved in ABA biosynthesis (NCED3), regulation of abscisic acid signaling (ABI1), and coding for a catalase enzyme (CAT2) known to favor H2O2 scavenging were monitored. During the experiment g s, A, and E values were most of the time higher in 2x compared to 4x. During the water deficit period, pot water loss decreased faster in 2x compared to 4x, leading to a faster decrease in all physiological parameters in 2x. The higher sensitivity of 2x compared to 4x was correlated with more numerous thinner roots, higher leaf ABA and H2O2 contents, and with the lower leaf water potential. ABI1 and NCED3 expression was not strictly correlated with the ABA content. However, the higher CAT2 expression in 4x was correlated with the lower leaf H2O2 contents. Therefore, the better tolerance observed in 4x ‘Carrizo citrange’ compared to 2x was associated with more limited water consumption and better and H2O2 scavenging.

Woody perennial species from temperate regions fall dormant during the cold winter season to avoid unfavourable conditions. To break out of dormancy and eventually flower, they must fulfil cultivar-specific chilling and heat requirements. Phenology analysis can clarify the climatic requirements of tree cultivars and thus provide critical information to ensure the future viability of orchards in warm growing regions, where warmer winters are expected as a result of climate change. We used Partial Least Squares (PLS) regression to correlate first bloom dates of 4 local and 3 foreign pistachio ( Pistacia vera L.) cultivars with daily chill and heat accumulation (quantified with the Dynamic Model and Growing Degree Hours Model, respectively) for 18-year records (1997–2016) from Sfax, Tunisia. PLS outputs allowed delineation of the chilling phase, during which high chill accumulation was correlated to early bloom, and the forcing phase, when this was true for high heat accumulation. Both phases showed discontinuities. During September and October, high heat accumulation appeared to first have a bloom-delaying effect, followed by a bloom-advancing effect, indicating that temperature during dormancy induction may affect bloom dates. Chilling requirements were estimated between 32.1 ± 2.3 and 33.3 ± 2.2 Chill Portions and heat requirements between 9974 ± 198 and 12,738 ± 235 Growing Degree Hours. This study revealed limitations of the Dynamic Model, which is often considered the most accurate among commonly used models, in the warm Tunisian climate. High temperatures during the chilling phase had a significant bloom-delaying effect on all pistachio cultivars. Low chill accumulation was related to very low yields and associated with zero production in 1995, 2001 and 2007. Low flowering percentage, high bud fall percentage, long and inhomogeneous bloom, and co-occurrence of several phenological stages on the same branch were symptoms of lack of chill in 2016.

International audience; For grafted plants, salt stress tolerance of the aerial plant part is poorly documented. Thus, we developed a simple, fast and inexpensive method to identify tolerant genotypes. Twigs of 14 mandarin accessions that we previously analyzed as seedlings were cut in solution to prevent embolism and were then evaluated in salt stress condition for a week. Physiological parameters such as gas exchanges, leaf Cl- and Na+, as well as the presence of H2O2 and the activity of enzymes involved in ROS synthesis and detoxification processes were analyzed. One accession known to be tolerant as rootstock was shown to be sensitive with limited Cl- translocation from the solution to the shoot while sensitive accessions when grown as seedlings presented limited wilting symptoms and accumulated large leaf Cl- content. A model is proposed to explain the different strategies of the plant to cope with high toxic ion content. This method allows separation of the root compartment, where ion exclusion mechanisms may exist and have an impact on the salt stress tolerance of the whole plant. (C) 2015 Elsevier GmbH. All rights reserved.