**7.1. Ripening physiology of drupes**

60 Olive Germplasm – The Olive Cultivation, Table Olive and Olive Oil Industry in Italy

pneumatic combs(De Simone & Tombesi, 2006; Tombesi et al., 2008).

shoots within the canopy becomes a rule.

eliminate shoots and suckers.

(unpublished data).

**7. Harvesting** 

volume of the canopy, while in the second case, the pruning will have the aim of bringing up the external wall of the canopy longer and pending fruiting shoots, to facilitate harvesting with

Pruning must be carried out at the end of winter, before the restart of vegetative growth. It must be avoided after the harvest, because it reduces the cold resistance of the plants and does not allow wounds to heal, favoring diseases from fungi or other parasites. Traditionally in late summer a second pruning is performed on adult plants to eliminate suckers inside the plants, with special reference to the vase shape, where the formation of

In profitable olive orchards pruning mechanization is essential to reduce management costs and regain timeliness in working, even though it penalizes the productive efficiency of trees. To balance the economic needs of management there are several ways to carry out mechanical pruning that should not be performed simultaneously on the entire plant. To ensure a good production of fruiting branches the canopy that remains after pruning should not excessively reduced. Mechanical pruning can be applied alternately in different years and/or rows by carrying out topping and hedging, reserving annual hand pruning to

Several experiments have been performed in different types of olive orchards in order to study the feasibility of mechanical pruning (Giametta & Zimbalatti, 1997; Ferguson et al., 1999; Ferguson et al., 2002; Peça et al., 2002; Tombesi et al, 2008; Dias et al., 2008; Farinelli et al., 2009). In our experience**,** the technical-economical convenience of pruning mechanization, also considering equipment integrated with pneumatic combs for olive harvesting, was evaluated. The results showed the good effectiveness of the pruning equipment in terms of cutting quality and working capacity (Pascuzzi et al., 2007; Toscano 2010a ). Other trials have been carried out to assess the performances and the effects of mechanical pruning, that was performed both with toothed disks and scissor blades pruning machines. Both resulted in great efficacy and work productivity; nevertheless, the first ones are more efficient for woody vegetation, up to 10 cm diameter, while the second ones work better on thin branches, even though it can cut woody branches up to 5 cm diameter

In olive grove management, the harvest is the other most expensive practice, together with pruning. Harvesting systems, can be considered rational only when they can reconcile the operation costs with the necessity to pick up the maximum yield in respect of the product quality. In the past, the availability of low cost manpower with a manual harvest allowed the satisfaction of these two demands, but the low availability and increase of the cost of labor, have made such operations excessively onerous, and applicable only to table olives.

Manual harvest can be improved using hand-held pneumatic combs to detach the olives from the plant that assuage the work, and give maximum flexibility in terms of harvesting

time, and increase the operators productivity, but it is time-consuming and costly.

The olive tree fruits (Olea europaea L.) are oval or round drupes, of variable weight according to the cultivar, the yield, the nutritional and health state of the tree. The drupe is constituted by the external exocarp (peel), by the fleshy mesocarp (pulp) and by the internal stone (pit). Fruit development and ripening are a combination of biochemical and physiological changes that occurred during maturity of fruit. The development process is characterized by changes in size, weight, composition, color, flavor and physical proprieties of the fruit (Connor & Fereres, 2005) and is critical for final yield and oil quality. Oil accumulation, which occurs from pit hardening to harvesting may be early or late depending on the variety, generally it starts in the northern hemisphere from the month of August and continues up to November-December, subsequently the increase of oil content in the drupes is apparent being due to water reduction.

The maturation of olives also varies depending on the crop load, environmental conditions, which are subject to strong annual variations, soil moisture, and cultural practices. At harvest, within a tree, not all the fruit are at the same ripening stage, in fact this parameter also depends on the position of the fruits.

For the olives to be used for the oil extraction, the harvest must have been carried out at the beginning of the ripening phase of fruits, at veraison, when the pulp changes its color from green to purplish red. This stadium corresponds to the maximum oil yield per hectare, since, even if subsequently a slight increase in the oil content of the drupes is had, the loss

for natural fruit drop undoes the advantage. In many instances the oil quality also decreases. An early harvest allows the production a good oil, rich in antioxidants and aromatic flavors, that confers resistance to oxidation, and a "fruited" taste. Instead, oils obtained from olives harvested at an advanced ripening stage are less intense, less bitter with a lower percentage of mono-unsaturated and saturated fatty acids and a higher percentage of poly-unsaturated fatty acids, that penalize its stability.

Cultivation Techniques 63

mechanization. Soil management, plant structure, fertilizer, irrigation, pruning and mechanical harvesting must be chosen according to variety and environmental features. The paper provides useful indications on the introducing of the cover crop to better soil

Moreover, olive trees respond very strongly to irrigation and take advantage of very low volume of water also with regulated irrigation deficit. With regards to olive pruning, this cultural practice must be managed rationally based on the harvesting system and both these techniques (pruning and harvesting) must be done mechanically to reduce the running costs

*Agricultural Research Council - Olive Growing and Oil Industry Research Centre, Rende (CS), Italy* 

Financial support for this study was provided by the Italian Ministry of Agriculture, Food and Forestry Policy through the project GERMOLI "Salvaguardia e valorizzazione del

AA.VV. (1989). Paolo Sequi (a cura di), Chimica del suolo,. Pàtron (ed.),Bologna, Italy. Agabbio, M. (1978). Influenza dell'intervento irriguo sul ciclo produttivo dell'olivo. Nota II: Influenza del regime idrico sulla biologia fiorale e sui caratteri morfo - qualitativi dei

Angelakis, A.N.; Marecos do Monte, M.H.F.; Bontoux, L. & Asano, T.(1999). The status of wastewater reuse practice in the Mediterranean basin: need for guidelines. *Water Res.*

Aparicio, R. & Luna, G. (2002). Characterisation of monovarietal virgin olive oils*. Eur. J.* 

Arrivo, A.; Bellomo, F. & D'Antonio, P. (2006). Raccolta meccanica dell'oliveto

Bacelar, E.A.; Santos, D.L.; Moutinho-Pereira, J.M.; Gonçalves, B.C.; Ferreira, H.F. & Correia, C.M. (2006). Immediate responses and adaptative strategies of three olive cultivars under contrasting water availability regimes: changes on structure and chemical

Bacelar, E.A.; Moutinho-Pereira, J.M., Gonçalves, B.C.; Ferreira, H.F. & Correia, C.M. (2007). Changes in growth, gas exchange, xylem hydraulic properties and water use efficiency

composition of foliage and oxidative damage. *Plant Sci* 170: 596–605.

*National Research Council - Institute for Agricultural and Forest Systems in the Mediterranean,* 

management in order to control erosion and maintain soil fertility.

Caterina Briccoli Bati, Elena Santilli and Pietro Toscano

GERMoplasma OLIvicolo delle collezioni del CRA-OLI".

frutti. Studi Sassaresi. Sez. III. Vol. XXV: 266-272.

for better crop competitiveness.

**Author details** 

Ilaria Guagliardi

**9. References** 

10: 2201–2217.

*Lipid Sci. Tech.* 104: 614–627.

superintensivo. *Inf. Agrario*, 1, pp. 68-71.

*(ISAFOM), Rende (CS), Italy* 

**Acknowledgement**

With regards to the harvesting method, oils with excellent quality can be produced with both manual and mechanical harvesting, as long as the drupes are intact and healthy.

For table olives harvesting is carried out manually from the plant, to avoid damage to the fruits that would consequently depreciate their market value. In some cases harvesting in the olive-grove is done in different steps as a consequence of the ripening scale, or performed at the same time and the sub-size fruits are sent to the crusher for oil extraction. To facilitate the harvest it is necessary that the plants are of a contained dimension, and with suitable forms that assemble the fruits on the outside of the canopy and on lean shoots.

In table cultivars for green fruit processing the harvest is done when the peel color changes to light green, that corresponds to the beginning of pulp softening and the maximum content of sugars, fundamental during tanning, for the fermentation process that follows sweetening, with lye or brine. For the olives destined for tanning to black, the harvest must be effected when the pulp is also colored, based on the physiological maturation of the fruits.

The most important parameters to determine the stage of maturation of the drupes are the fruit separation force and the development of natural fruit drop. Before the natural fall of olives there is an attenuation of the force with which they are attached to branches and shoots. These physiological changes do not occur simultaneously on all the drupes of the same tree but occur with a certain scaling. Therefore, the decrease of the attachment strength of the fruit and the drop of the first fruits are the most important indices of the final stage of ripening. These indices are easily determined and able to predict with sufficient reliability the time to start harvesting.

The optimal time of harvest can be, further, defined as one in which there is a high amount of fruit on the plant capable of being detached by the machines in considerable percentages and with a high content in good quality oil when ripening the pulp becomes less consistent (Farinelli et al., 2006).
