Il settore dell'olivicoltura da tavola in Italia: situazione e prospettive

The Italian table olive industry is almost completely located in the southern regions: Sicily and Apulia together account for about 2/3 of the entire national production. ‘Nocellara del Belice’,‘Nocellara etnea’, ‘Bella di Cerignola’ and ‘Ascolana tenera’ are the leading cultivars together with a large number of other local traditional varieties, often utilised for a double purpose (table olives and oil production). Although Italy is nowadays largely dependent (for about 60%) onto import from other Countries (mainly Spain, Greece and Morocco) the domestic production has been declining in the last thirty years and currently accounts for about 3-4% of the total world production against a value of about 10% of the period 1980/85. Nevertheless, some interesting examples of specialized production concentrations are still represented by the producing areas of the ‘Nocellara del Belice’, ‘Bella di Cerignola’ (syn. ‘Bella della Daunia’) and ‘Ascolana tenera’ which recently received the DOP (protected designation of origin) recognition. In this paper, besides the overall review of the Italian varietal platform and a brief description of the main cultivars, the advantages and the opportunities offered by the application of specialized cultural techniques are discussed, with special emphasis on the positive role of a more appropriate and wide diffusion of irrigation (including RDI) and chemical fruit thinning. Potential of other cultural techniques such as fertilization, pruning and pest and disease control are also reviewed with reference to the possible role in fruit quality enhancement together with the needs for further development of the entire table olive industry and the R&D involved

Influence of propagation techniques on growth and yield of olive trees cultivars ‘Carolea’ and ‘Nocellara Etnea’

The vegetative and productive performance of micro-propagated olive plants in comparison with grafted and own-rooted plants was evaluated in southern Italy. Two cultivars of Olea europaea L. ‘Carolea’ and ‘Nocellara Etnea’, were planted in 1997 at two-row spacings: 6 m 3 m and 6 m 6 m. Percentage of flower bud differentiation, fruit weight, yield, pruning material and trunk diameter were measured on each plant of the experimental plot. Plants came into flowering the second year after planting with significant differences between cultivars. Micro-propagated ‘Nocellara Etnea’ plants came into bearing as early as the second year, whereas grafted plants had no bearing. Eight years after planting, cumulated yield of ‘Nocellara Etnea’ plants was almost double as compared to the ‘Carolea’ plants. Yield from micro-propagated plants was slightly higher with respect to grafted plants in ‘Nocellara Etnea’, but fruit weight was significantly lower. Micro-propagated ‘Carolea’ plants have shown a similar percentage of flower buds but a very low cumulated yield in the period of the trial, due to poor fruit set. In general, vegetative growth was significantly higher on plants with lower crop level. Our results have shown that micro-propagated plants did not exhibit any juvenile trait as, for instance, delay in flowering. In vitro propagation can thus be a rapid and a powerful olive propagation technique. Further investigations are however necessary to check if the main phenological differences observed (average fruit weight and poor fruit set) are somehow due to genetic modifications induced by in vitro propagation

The influence of mychorrizae on the vegetative growth of five Olea europaea cultivars

The artificial mychorrization, in nursery phase, becomes useful particularly when the populations of native fungi are not present or have been reduced by intensive agricultural practices. We show preliminary results on the effects of mychorrizic symbiosis induced in five cultivars of Olea europaea: Carolea, Coratina, Maiatica of Ferrandina, Leccino and Tondina. During the experimentation, self-rooted cuttings, approximately 500 per each cultivar, were inoculated, in correspondence of the two transplants in pot, with: Glomus intraradices, Glomus spp., Glomus spp. + Trichoderma sp. + bacteria. The plants have been grown, according the ordinary management techniques, guaranteeing an optimal water status and apporting limited fertilization. The percentage of mychorrizic colonization has been high, with values to 100%, while the intensity of mychorrization results variable, from 20 to 50%. Destructive and not-destructive biometric measurements were carried out to estimate eventual variations in terms of plant growing rate and stored dry matter. Altogether, in the first eighteen months, all the inoculated treatments showed greater increments, from 8 to 20%, than controls; Glomus intraradices determined the best result, +20%. However, a strong interaction inoculo-cultivar emerges; Maiatica cultivar, in fact, reached higher stem diametrical increments, +20%, with the Glomus spp.; Carolea cultivar, +11%, and Coratina, +33%, with the Glomus spp. + Trichoderma sp. + bacteria; Leccino and Tondina confirmed the efficiency of Glomus intraradices, +29% and +24%, respectively

Soil management affects carbon dynamics and yield in a Mediterranean peach orchard

A field trial was conducted over a seven-year period, in Mediterranean peach orchard. The aims were (i) to explore the effects of alternative soil-management practices (Amng) on soil and litter carbon (C) reserves, (ii) to monitor the seasonal and (iii) spatial variations of soil CO2 flushes. The alternative management included no tillage, retention of all aboveground biomass and application of imported organic amendments (15 t ha−1 y−1 fresh weigh). Locally conventional management (Lmng) served as the control: i.e. tillage, mineral fertilisation, removal of prunings. The mean total annual C inputs were 4.2 and 2.4 t ha−1 in Amng and Lmng, respectively. Spatial and temporal variations in CO2 soil emissions over a 20 m2 plot (×2) were assessed (Li-6400, LI-COR, USA) on the assumption that root topography and microbial activity declined systematically with distance from the row line. Under Amng practices soil C significantly increased up to 1.78% against 1.38% at Lmng block. The C stored as litter and dead wood in Amng, was 16-times that in Lmng. On a whole-season basis, CO2 losses were 20% higher in Amng than in Lmng. Soil CO2 emissions were mostly from the in-row, with the inter-row emissions being lower, especially due to reduced soil-water content during the drier months. It is concluded that despite a higher CO2 soil emissions, alternative management techniques will partially offset atmospheric CO2 rise through increased soil C reserves, and that spatial variability of emissions must be taken into account if the accuracy of estimates of large-scale emissions are to be improved

Long-term consequences of tillage, organic amendments, residue management and localized irrigation on selected soil micro-flora groups in a Mediterranean apricot orchard

In semi-arid Mediterranean environments, the loss of soil fertility can be avoided through the optimization and innovation of low environmental impact agricultural techniques. Such ‘innovative’, suitable agricultural management practices can have positive effects on soil microbial communities. The aim of the present study was to explore the effects of two different agricultural systems (‘innovative’ and ‘conventional’) on the diversity of important groups of microorganisms related to soil fertility, such as fungi, actinomycetes, Pseudomonas spp., Bacillus spp., Azotobacter spp., proteolytic and ammonifying bacteria. The study was carried out in an apricot orchard located in Southern Italy. Since 2003, half of the orchard was managed adopting no-tillage, cover crops, compost application, drip irrigation, winter pruning and limited mineral fertilization, whereas the other half was subjected to ‘conventional’ management. Soil samples were randomly collected from the superficial soil layer in four different orchard positions: innovative along the inter-rows (IIR) and under drip emitters (IUE), and conventional along the inter-rows (CIR) and under drip emitters (CUE). Higher populations of total bacteria, actinomycetes and proteolytic bacteria were induced by IIR treatment, whereas Pseudomonas spp., Azotobacter spp. and ammonifying bacteria showed increased populations in IUE. No differences between the treatments were found for total fungi and Bacillus spp. The higher inputs of organic matter of innovative plots caused an increase in the microbial groups responsible for nitrogen metabolism in well-watered zones (IUE), and higher activities of decomposer and humus-forming microorganisms in IIR. Results show that suitable agricultural practices can have positive effects on microbial activities and complexity, which in turn influence soil fertility

IDENTIFICATION OF TIE-RODS TENSILE AXIAL FORCE IN CIVIL STRUCTURES

This paper is concerned with the problem of identifying the tensile axial force of metallic tie-rods used in civil structures. Tie-rods are generally used to transfer a tensile force between different structural elements. Specifically in civil structures, they are often used to unburden the lateral load exercised by the vaults and arcs on walls or columns, in ancient monumentalmasonry buildings as well as in modern concrete/iron constructions. A direct measure of this force is impossible and the tension is an unknown variable, as are the boundary conditions expressed by the constraints. Thus, in such a scenario, the characteristic equation has no analytical solutions. The paper proposes an experimental technique developed to identify, in situ, the tensile force on the rod. The identification method uses the first modal frequencies of the structure, identified by measuring the frequency response functions (FRFs) with instrumented hammer excitation. The frequencies are used to characterize some correlation indexes that change according to the variation in the tensile axial force of the rod. An FEM code numerical model allows to identify where the change in correlation indexes along the tie-rod could be greatest, in order to arrange a suitable measurement set up. Then the numerical model provides an evaluation of the tensile force corresponding to the set of correlation indexes identified. An estimation of the error in the identification of the force is given by a reasonable interval of stiffness of the constraints. The technique has been tested on laboratory system. © The Society for Experimental Mechanics, Inc. 2014