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In Portugal, olive (Olea europaea L.) groves with the traditional tree density of around 100 trees ha -1 require an urgent reduction in production costs in order to survive. This requirement becomes imperative at the present state of low prices of olive oil in the world market. The authors have been studying, since 1997, a mechanised alternative to the expensive and labour intensive manual pruning practice (Dias et al., 2012), (Dias et al., 2008), (Peça et al., 2002). Three treatments were followed in field trials:T1 - manual pruning with a chain saw, performed in 1997, 2006 and 2011;T2 - mechanical pruning, performed by a tractor mounted cutting bar provided with 6 circular disc-saws, in 1997, 2006 and 2011. In 2011 the mechanical pruning was followed by a manual pruning complement to eliminate the great diameter suckers from the central part of the canopy; T3 - mechanical pruning, as in T2, followed by a manual pruning complement in 1997, 2006 and 2011. In 1997 and 2011 the manual pruning complement was done immediately after the mechanical pruning. In 2006 only mechanical pruning was done and the manual pruning complement intervention was done in the following year (2007). The effect of the above treatments on olive yield was evaluated at an annual basis for 15 years. The main results showed that over the first 9 years period mechanical pruning (T2) revealed a higher accumulated yield. However, over the following 6 years period, the yield obtained by the mechanical pruning treatment (T2) was a lower than the yield of the other two treatments, which showed to be similar. Following this results a pruning strategy was put forward based on mechanical pruning, complemented by manual pruning. The manual pruning complement should always be evaluated on a case by case basis, although this study points that it could be performed after the second or third mechanical pruning intervention.

Olive producing countries invested largely in high density groves varying from 200 to 550 trees per hectare for which no efficient totally mechanized harvesting methodology and technology is available. Continuous canopy shaking is the obvious approach, not only increasing working capacity but also overcoming the problem of scarce and expensive labour. The equipment available today follows the over-the-row concept for which tree growth is a limitation. Large over-the-row olive harvesters, mainly of South American and Australian design, are too heavy and expensive, hardly suitable to the difficult wet soil conditions encountered in the Mediterranean countries. The side-row concept is the obvious alternative. Furthermore it tends to be simpler and less expensive, meaning lower purchase running costs. In 2009 a research project was set to develop such technology. The equipment comprises two symmetrical harvesters that follow a tree row one at each side. Each harvester is a trailed type structure towed by a farm tractor which also drives the harvest hydraulic power pack. A second operator controls the harvest through electro-hydraulic controls. A vibratory rotor with flexible rods detaches fruits which are collected at a catching platform. Fruits are conveyed to a temporary storage bag which is hydraulically lowered to the ground when full. The row side of the harvester is bordered along the edge by flexible synthetic interface with the tree trunk. The prototype was given a two harvesting campaign trial and the basic concept is now set. This paper gives an account of the project and describes the technical challenges for the next stage of translating the prototype into a viable product for the market.

Air and soil temperatures have often been used as driving variables in numerous crop growth and development models as well as in those referred to soil like mineralization, evaporation or transpiration. Temperatures (and moisture) profiles above and beneath soil surface change when a vegetation cover above a bare soil is introduced. The aim of this work was to evaluate (a) the soil thermal behavior in two olive orchards (Olea europaea), both grown on soils with little profile development (Regosol and Cambisol) and subject to drip irrigation but with different spacing between trees, and (b) the air thermal profile over olive rows. Experiments were performed from April to June 2012 in Southern Portugal. Soil and air temperatures were measured by thermocouples. The two orchards changed spatial distribution of soil surface temperature, soil temperature profiles and air temperature within the canopy, either on a daily or hourly basis. Olive tree spacing and irrigation affected both the soil thermal behavior and air thermal profiles. Tree spacing affected the horizontal gradients established along the interrows (intensity and rhythm). Irrigation reduced hourly and daily mean soil surface temperatures and daily thermal amplitudes and increased damping depths in both profiles. Along the row, the effect of shading seems to overlap that of irrigation in an hourly basis.