Long-Term Evaluation of the Influence of Mechanical Pruning on Olive Growing

In Portugal, olive (Olea europaea L.) groves with the traditional tree density of around 100 trees ha -1, necessitate increasing pruning costs every year. As a result farmers tend to lengthen pruning intervals. With the purpose of studying a mechanised alternative to the expensive, labor-intensive manual pruning practice, the authors established in 1997 field trials with the following three treatments: i) manual pruning with a chain saw; ii) mechanical pruning, performed by a tractor mounted cutting bar provided with 6 circular disc-saws; and iii) mechanical pruning, as in the mechanical pruning treatment, followed by a manual pruning complement. The effect of the above treatments on olive production and on harvesting efficiency was evaluated every year for 8 yr. The harvesting was performed by a trunk shaker, and the remaining non-detached fruits were collected manually. The pruning rate of mechanical pruning (487 trees hour-1man-1) was substantially higher than the values of manual pruning and mechanical+manual pruning, which were the same (20 trees hour-1man-1). Over the 8-yr period, mechanical pruning had an average yield of 36,4 kg tree-1 year-1 which was significantly higher than the 30,1 kg tree-1 year-1 of manual pruning and no significantly different from the 34,1 kg tree-1 year-1 of mechanical+manual pruning. The shaker efficiency was significantly influenced by the year, ranging from 72% to 96%; no significant differences were found between treatments in terms of harvesting efficiency. These tests indicate that after mechanized pruning (horizontal cut at the uppermost part of the canopy) trees can be kept for at least 8 years without any significant loss in olive yield per tree and no effect in harvesting efficiency, therefore reducing costs. Selective manual complement to the mechanized pruning, performed in the same year, does not provide any further advantages in olive yield nor in shaker performance and consequently increasing production costs

Influence of umbrella pine (Pinus pinea L.) stand type and tree characteristics on cone production

Most umbrella pine (Pinus pinea L.) stands are managed as agroforestry systems, whose main production is fruit, due to the edible and highly nutritious kernels, and are frequently associated to natural or seeded pastures and grazing. The stands have low density, in order to enhance crown growth and fruit production. Nevertheless, cone production, both with regard to number and weight, varies greatly between stands, trees and years. In this study were selected three agroforestry systems, representative of umbrella pine stands whose main production is fruit, and one stand representative of the timber production system, where fruit is the secondary production. It was evaluated the variability in cone production as a function of the tree’s diameter at breast height and crown diameter and the individual tree’s competition status. The results indicate that stands managed in agroforestry systems with lower competition and individuals with larger diameter at breast height and crown diameter tend to produce more and heavier cones per tree. The first two principal components of the principal component analysis explain 84 % of the variance in cone production, trees’ dimensions and competition index. Tree competition status has a negative impact on production per tree

Performance of the “Oli-Picker” olive harvester in Trás-os-Montes region of Portugal

Trunk and bough shakers are common equipment for olive harvesting. Not surprising information concerning their performance is available. For less usual equipment like canopy shakers, however, there is lack of information relative to their field work. This paper deals with the performance of an “Oli-picker” harvester which is basically a rotor device brushing the canopy, mounted on a structure making possible it to work anywhere, inside or around the olive tree crown, detaching olives. This paper presents results from two years of observation in olive orchards of Trás-os-Montes (northeast of Portugal), including the methodologies of work followed in the field and the work rates found

Contribuição para a optimização da data de início de colheita mecânica de azeitona

O equipamento de colheita de azeitona não recolhe frutos que se encontram no chão devido à queda natural, bem como os que permanecem na árvore após a vibração. O olivicultor quererá que qualquer destas fracções seja a menor possível, o que remete a questão para a crucial decisão da data de início da colheita

Prototype of a side-row Continuous Canopy Shaking Harvester for Intensive Olive Orchards

Olive producing countries worldwide 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. Trunk shaking is not an adequate option due to lack of space and intense strain in labour and machinery. Continuous canopy shaking is the obvious approach, not only increasing working capacity but also overcoming the problem of scarce and expensive labour. Continuous canopy shaking harvesting equipment available today are adapted over-the-row grape or coffee-beans harvesters. Recently purposely built, rotor type, 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. Tree growth is a limitation for the over-the-row concept. These harvesters may be used for a considerable number of harvest campaigns in groves of the limited growth Arbequina cultivar, but only up to the third production year in groves based on normal growth local cultivars. Tree growth limitation can only be adequately dealt with the side-row concept. Furthermore the side-row concept tends to be simpler and less expensive, meaning lower running costs. In 2009, the SIDE-ROW CONTINUOS CANOPY SHAKING FRUIT HARVESTER project was set to develop such technology. This paper describes a prototype and gives an account of the different stages of its development. The equipment comprises two symmetrical harvesters that follow a tree row one at each side. Each harvester is based on a trailed type structure towed by a farm tractor which also drives, through its power-take-off, the hydraulic power pack that ensures hydraulic energy for most of the hydraulic actuators. An operator in the control station controls the harvest through electro-hydraulic controls. A vibratory rotor with flexible rods is used for engaging and shaking the fruit bearing branches. Each harvester also comprises a catching platform with conveyors belts delivering fruits 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. After two harvesting campaigns the basic concept is now set. Minor detail solutions will be addressed in 2013. Investors are now being attracted to finance pre-series machines intended for durability tests which will define the product for the market

Estudo comparativo do desempenho de três sistemas de colheita mecânica de azeitona

Ao longo de três anos, foi realizado trabalho experimental em olivais com densidades de plantação compreendidas entre 100 e 150 árvores por hectare, utilizando três sistemas de colheita mecânica de azeitona, que permitiram obter resultados de capacidade de trabalho (árvores por hora). Nos três sistemas, para o destaque dos frutos foi usado o mesmo vibrador de troncos. A diferença está na recolha dos frutos derrubados: no sistema (A) foi realizada manualmente; no sistema (B) foi efectuada com um enrolador de panos montado em tractor; no sistema (C) utilizou-se um apara-frutos. Os resultados obtidos nos ensaios de campo, permitem (1) apontar as limitações de cada um dos sistemas e (2) sendo conhecida a capacidade de trabalho do sistema que recolhe manualmente a azeitona, estimar para os mesmos olivais e condições de trabalho, os valores de capacidade de trabalho dos sistemas que recolhem a azeitona mecanicamente

Mechanical versus manual harvest of Pinus pinea cones

Umbrella pine cone production is an important forest non-wood product in Portugal,especially in the region of Alcácer do Sal, where it plays an important role to the local development. Traditionally umbrella pine cones are manually harvested, increasing production costs and, above all, with very high accident risk to the workers. The development of equipment for mechanical harvesting started in Italy in the 1980's. Studies report different values for harvesting efficiency and tree damage, the latter in terms of immature cones and branches detached. In this study a trunk shaker was used to evaluate mechanical harvesting both in terms of efficiency and tree damage induced by trunk vibration. In comparison to the manual process, time required for mechanised harvesting was about 1/15th of the time. The results revealed a mechanical harvesting efficiency higher than 86% with negligible tree damage. Inter-annual harvest efficiency variability was also observed

Influência da vibração ao tronco ou às pernada na capacidade de trabalho e nos custos da colheita mecânica de azeitona

Ensaios de campo realizados em Trás-os-Montes e no Alentejo mostram como a capacidade de trabalho e custos de operação são afectados quando em consequência da geometria e dimensão das oliveiras há necessidade de efectuar a vibração à pernadas, em vez da mais expedita vibração ao tronco. Os resultados obtidos são úteis para uma tomada de decisão, particularmente por parte dos agricultores possuidores de olivais menos adaptados, que tenham como objectivo adoptar a colheita mecânica

Influence of trunk or bough shaking on the performance and costs of mechanical harvesting of olives

Field trials carried out in Portugal showed the penalty to be paid, both in terms of work rate and costs, whenever, due to tree geometry and size, trees had to be bough shaked rather than the normal trunk shaking. If an olive orchard with trees requiring two bough shakings could be adapted to an entirely trunk shaking orchard, simulation shows an increment between 9% and 33% in the work rate at harvesting and a reduction between 4% and 22% in harvesting cost per kilogram of olive, assuming a 4000 trees size orchard. The data collected is regarded to be very useful for decision support, particularly for those farmers owning less adapted olive orchards, aiming to adopt mechanized harvesting

Assessment of a Side-Row Continuous Canopy Shaking Harvester and Its Adaptability to the Portuguese Cobrançosa Variety in High-Density Olive Orchards

The olive tree is an important crop in Portugal, where different levels of intensification coexist. The traditional olive orchards present profitability problems, mainly due to harvesting, so there has been a drastic reconversion towards high-density or super-high-density olive orchards. The latter present major constraints due to very specific needs for their use, being practically destined for new orchards. Consequently, the possibility of using systems based on canopy shakers in high-density olive orchards with local varieties is promising. The objective of this work is to evaluate a prototype canopy shaker for the harvesting of high-density olive orchards of the Portuguese variety ‘Cobrançosa’. The evaluation is based on the study of canopy shaking in order to adapt canopy training and the adaptability of the machine. For this purpose, the vibration of 72 points of the tree canopy was recorded and a qualitative assessment of the harvest was carried out. Differences were found between the different zones according to the direction of the forward movement of the harvester and the distance to the trunk. These differences were associated with the values obtained for fruit detachment, and a greater quantity of fruit was harvested in the areas of the canopy in contact with the rods