I handle of the irrigation and the poda in plantations of olive grove in fence

More recent still is a system of crop of the olive grove where the density increases spectacularly, happening of the 100 and 300 olivos/has to 1.500-2.000 olivos/has. In this new type of plantations, calls in fence or superintensivas, the olivos form to an axis and the distances between trees vary of 1,35 to 2 m. This does that, after three years of growth, form continuous fences that they are collected by machines cabalgadoras.

Plantation olive grove in fence in Finca The Order, variety arbequina.

The first experience of olive grove in fence realizar in Italy, but the commercial plantations of fence arose in Spain in 1993 extending to other countries like Portugal, France, Italy, Morocco, Chile, Tunisia or United States. Since, the increase in the number of hectares planted has gone in increase being able to estimate that in the actuality can find around the 100.000 has. In Spain concentrates 50% of the world-wide total of olive groves in fence. The success of this system resides in two big advantages in front of systems less intensive: the fast entrance in production and the mechanisation of the operations of crop, mainly recolección and poda. This reduces drastically the hand-held need of own work of the traditional crop and that constitutes ones of the greater economic problems for the sustainability of this crop.

However, this olivicultura of high density presents a series of inconvenient as they are the high costs of implantation together with some technical conditionings like the require of varieties little vigorosas, plots of crop of some dimensions, little rugged, in irrigation and with availability of machinery. To this add him that the handle of the crop is more complicated mainly regarding the control of the vigour that is a critical appearance of the system that conditions the maintenance of the productivity and therefore the profitability and useful life of the plantation.

Inside the costs of maintenance of the olive grove, the recolección, the irrigation and the poda are those that suppose a greater percentage inside the economic balance total of the exploitation with 75% of the total of the costs. Whereas the recolección this practically resolved with the utilisation of machines cabalgadoras that speed up this work and reduce his cost, a good management of the irrigation and the poda are key points of success of this system.

The CICYTEX-Finca The Order carries working from the year 2009 in irrigation in olive grove in fence and from the year 2011 in strategies of podas semimecánicas and totally mechanised in these systems and has of preliminary information on the handle of these two works of crop.

For a correct use of the water of irrigation is important to know so much the needs hídricas of an olive grove, like the sensitivity to the fault of water in each phase of crop and like this can design the best strategy of irrigation that make compatible production, quality and profitability and obtain the potential maximum of this resource.

On the one hand, it is necessary to differentiate between plantations in learning and plantations adults for the design of the correct strategy. When we find us with young plantations in learning is important to favour the growth of the trees to reach the before possible the full production. In traditional and intensive plantations of olive grove recommends the use of an irrigation with total needs for the first years of the crop and desaconseja totally apply strategies of irrigation deficitarias. However, in the case of the olive grove in fence, reaches a high percentage of interception of radiation a lot before that in the others systems, by what the use of irrigations deficitarios in the first years could be an interesting option. The aim is to achieve a good productivity and a control of the vigour of the fence that is one of the greater problems of these systems with varieties no adapted entirely to freamers of plantation so extremely intensive.

Regarding the different sensitivity to the fault of water according to the cycle of the crop can distinguish 3 very clear-cut phases:

• Phase I: it initiates with the brotación of the tree (first of March), continuing with the flowering-cuajado of fruit to finalise with the hardening of the bone of the olives (first of July).
• Phase II: it comprises the period from hardening of bone and finalises to the start of September (10-15 days before envero).
• Phase III: it covers from start of September until the harvest (November).

The phase II is the less sensitive period to the fault of water and where greater cuts in irrigation can realizar without going down the production of the olive grove and save big quantity of water when being the period of elder sues hídrica. By the contrary, the phase I and III are sensitive periods to the fault of water since a cut of discharge, even light, would go down the final production of the crop although it can have some advantages that suits to value: a cut in the water applied with insufficient doses to cover the needs of the crop would control the vegetative growth (phase I) and would increase the performance graso of the olives in phase III.

In the CICYTEX- Finca The Order, have tested different strategies of irrigation deficitario in olive groves in fence in learning during the first 4 years of development obtaining results very interesting with the employment of a light deficit in these first stadiums. The use of dose of irrigation 40% inferior to a strategy of irrigation to cover the needs of the olive grove (4.000 m3/has to average in the 4 first years for total irrigation), did not suppose a loss of productivity in the plantation with productions surroundings to the 10.000 kg/has to average, with the advantage of a greater control of the vegetative growth (7,8% less than volume of glass) and therefore less intensity in podas of learning quantified in 16% less. This strategy of irrigation deficitario controlled applied with a different percentage according to the phases of crop taking advantage of the maximum the periods but and less sensitive to the fault of water and was of the 75-40-65% for the phases I, II and III respectively, considering the values porcentuales with regard to the needs of the olive grove. However, it did not achieve increase the performance graso at the end of the crop, for which it is necessary to apply treatments more severe that involves a loss in production of olive.

In olive grove can differentiate 3 types of poda according to the development of the plantation: podas of learning, of production and of renewal.

The poda of learning is used to realizar in the 3 first years after the implantation and consists in keeping the tree in a central axis with the respective tied each 20 cm to the tutor. The only intervention of poda that has to realizar is the one to leave 1/3 free of the inferior part of the free tree of branches.

When splitting of the third year begin to realizar poda of production. This consists in a poda of recess or ‘topping' to keep the tree in height, a poda lateral to avoid an excessive width of the fence and finally a poda of the skirts or ‘Skirting' to delete branches bajeras that prevent the treatments herbicides and that besides is a zone that the machine of recolección does not collect.

• The poda of recess or topping realizar mecánicamente with bar of rotary presses and sharp disks to a height between 2,5-2,7 m to avoid the sombreamiento of the sides of the fence (freamers of plantation around 3,5 m of street) and to keep the suitable dimension for the pass of the cabalgadora in the recolección of the olive. The period is used to to be in winter (February) although it can be interesting realizar it in summer (August) or even in both periods (2 times to the year). This is a subject that interests to tune by means of works of investigation and experimentation to check that period or frequency is the most correct to use.

• The poda lateral consists so much in keeping a width of the fence adapted for the machine of recolección (100-120 cm) like keeping the central axis and avoid that the olive grove go back improductivo by an excessive sombreamiento internal give the fence. This type of poda is used to to realizar manually due to the fact that the lateral interventions are used to to be few and consist in deleting branches with big dimensions directed to the street. Even so, the cost that supposes this type of poda can elevate the costs of production and every time are more the olivicultores that are opting by a total mechanisation of the poda. The machinery would be the same that the used for the topping but with a vertical orientation and to a distance of some 20 cm of the axis of the tree. This type of poda is used to to realizar on a face of the fence (poda by faces), keeping the another without touching to ensure production, and deleting the another to the following year (poda to 50%) or each two years (25%) depending on the recovery of the fence. Also it can do by streets with a machinery with two arms of disks. In this case it would happen in a street of each two (50%), each three (33%) or one of each four (25%).
• Regarding the poda of branches bajeras or Skirting is used to to do mecánicamente with machines trimmers of basses that join up to the leading part of the tractor or with cortadoras of manual fence to a height between 50-60 cm of the floor.

The total mechanisation of the poda or the use of a system combined semi-mechanical (manual in the sides and mechanical in height and bajeras) supposes important savings in the costs of this operation of crop in 90% and 65% in peonadas regarding a poda totally manual desaconsejada in these systems. Although with the first type the hand-held saving of work is considerable, the podas are not selective and it will be necessary to value productively speaking the length and maintenance of the feasibility in these plantations.

Finally, the poda of renewal only will be precise in case that the olive grove of fence leave to be productive because of an evil handle or aging of the crop. In this case they are miscellaneous the options to be followed all they valid and to choose to criterion of the agriculturalist:

To) Renewal by means of podas consistent in cutting the trunk of the fence being the best solutions tested to some 5-10 cm of the floor.

b) Elimination of a tree of each two and transform the the superintensivo in an intensive olive grove.

c) Start the plantation and realizar a new.

In the CICYTEX- Finca The Order is realizar an essay testing different strategies of poda of production in an olive grove in fence from his 4º year from plantation (2011-2013). The strategies employed consist in three podas semimecánicas and a poda totally mechanised. Between the semimecánicas the only difference is the period and frequency of the the poda of recess or topping, being the poda lateral manual and the one of the zones bajeras mechanised in all the cases.

The first strategy 'P1' consists in a poda topping in winter, whereas 'P2' was in summer and 'P3' in winter and summer. The poda totally mechanised 'P4' consists in a topping in winter, poda lateral mechanised to 25% by faces and poda mechanised of the skirts. The results after three years of experience show that the productions only went slightly inferior in the poda 'P3' (topping winter-summer) whereas in the rest of treatments was similar. However, they exist indications that the content graso miscellaneous with the strategies of poda employed showing 'P3' and 'P4' the greater contents grasos that translated in a greater production of oil of the trees with poda totally mechanised (P4) and compensated the production of oil in the treatment 'P3' (2 topping). These data are promising regarding the total mechanisation of the crop although it is necessary to study these strategies of poda to longer to see if they sustain in the time and do not wane the productions by the use of podas no selective.

Conclusions

Can conclude regarding the handle of irrigation and poda in olive grove that the use of strategies of irrigation deficitarias light (>40% of an irrigation according to total needs) result very advisable in olive groves in fence of learning since they keep the productivity and control the vigour during the learning of the fence. Regarding the podas of production, the total mechanisation of this operation can result extremely interesting since it supposes a saving in costs of crop. Keeping the productivity of the fence, so much in the strategies of irrigation as in the ones of poda, is necessary to evaluate the effect to half and long term.

Gratitudes

This work has been funded by the INIA (RTA2008-00033-C 02-00), CICYTEX and by the FEDER.