Canopy Shaker Research Articles

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.

Simulation study and field experiments on the optimal canopy shaking action for harvesting Camellia oleifera fruits

With the increasing cultivation scale of Camellia oleifera in China, the demand on the mechanical harvesting machinery is very urgent. Inefficient fruit harvesting has become a bottleneck hindering the development of Camellia oleifera industry. In order to achieve high fruit harvesting percentage and low detachment percentage of the flower buds, a canopy shaking mechanism is proposed for massively harvesting Camellia oleifera fruits which applies the reciprocating linear motion of multiple beating-bar arrays to the tree canopy. The multiple beating-bar arrays driven by the eccentric disk can generate comb-brushing effects on the tree canopy. Three kinds of Camellia oleifera tree architecture were modelled and their dynamics were simulated by finite element analysis. Their modal analysis results show that the low-order natural frequencies of the Camellia oleifera trees with different canopy shapes are very close. According to harmonic response analysis, the low-frequency excitation is used to harvest Camellia oleifera fruit. The orthogonal experiments were carried out on the canopy shaker prototype with the motor speed, reciprocating stroke and duration of vibration as the influencing factors, and the fruit harvesting percentage and the detachment percentage of the flower buds as the evaluation indices. The results show that the same optimal parameter combination can be used for three kinds of Camellia oleifera tree architecture, in which the motor speed is 360 r/min, the reciprocating stroke is 80 mm and the duration of vibration is 8 s. The average fruit harvesting percentage is 72.3% and the average detachment percentage of the flower buds is 13.9%.

Suitability of two dwarfing citrus rootstocks for ‘Salustiana’ orange trees grown under super-high-density conditions with mechanical harvesting

ABSTRACT Even though super-high-density plantation systems could maximise yield per acre and induce an early entry production, a few research studies have been conducted on citrus crops in the Mediterranean Basin. In this study, we assessed the suitability of ‘Salustiana’ orange trees (Citrus sinensis) on two dwarfing rootstocks [Forner-Alcaide 418 (FA418) and Forner-Alcaide 517 (FA517)] under super-high-density plantation systems. Tree growth, yield and fruit quality of ‘Salustiana’ on both citrus rootstocks were evaluated. Furthermore, the suitability of mechanical harvesting was evaluated using an over-the-row continuous canopy shaker for this citrus plantation system. For this last purpose, the effects of mechanical harvesting on fruit detachment and fruit harvested and tree damage were analysed. The results showed that ‘Salustiana’ orange on FA517 obtained a better response than on FA418 in terms of vegetative growth, effective yield and fruit quality under super high-density conditions, also displaying a better response to mechanical harvesting with a high detachment efficiency of fruits. It emphasised the relevance of proper mechanical pruning to reduce the tree damage and improve the detachment efficiency by this canopy shaker. Thus, although the over-the-row canopy shaker requires some technical improvements, it showed a high potential for harvesting super-high-density citrus crops for the juice industry.

Performance evaluation of lateral canopy shakers with catch frame for continuous harvesting of oranges for juice industry

Citrus is mainly oriented to fresh consumption, and harvesting is usually performed manually. However, the high cost of harvesting and the low availability of labour can compromise the profitability of the crop when it is destined to juice industry. The development of citrus mechanical harvesting for industrial processing is conditioned to reach a high fruit removal efficiency, with a reduced damage to both fruit and trees. The current machines available are very large, requiring extensive plantations with long rows of trees to be efficient. In this study, two lateral canopy shakers equipped with a catch frame were evaluated to harvest independently both sides of the hedge on intensive citrus plantations with the main objective of determining their performance and feasibility. The lateral canopy shakers tested were three tractor-drawn machines, one commercial machine and two prototypes. The tested machines reached a mean value of 78% of fruit removal. Besides, the prototypes, equipped with a catch frame, were able to recover a mean value of 70% of yield. Although the results were promising, for achieving an efficient result, the application of this harvesting technology still requires a process of improvement, and the adaptation of both the machine and the plantation. The machines should reduce the amount of post-harvest ground fruit (5.9%-10.4%). Tree damages generated by the contact of the catch frame with the trunk and the metal rods with main branches were the most relevant. Therefore, it is still necessary to increase the ground speed of the machinery and improving the design of the rods, regulating the rod penetrating deep in the canopy to improve the fruit recovery and limit the damage caused to the trees. Keywords: harvester, mechanical harvesting, fruit removal, tree damage, Citrus sinensis L. Osbeck DOI: 10.25165/j.ijabe.20201303.4998 Citation: Sola-Guirado R R, Castro-Garcia S, Blanco-Roldan G L, Gil-Ribes J A, Gonzalez-Sanchez E J. Performance evaluation of lateral canopy shakers with catch frame for continuous harvesting of oranges for juice industry. Int J Agric & Biol Eng, 2020; 13(3): 88–93.

Evaluation of Olive Pruning Effect on the Performance of the Row-Side Continuous Canopy Shaking Harvester in a High Density Olive Orchard.

In 2009, the Side-Row Continuous Canopy Shaking Harvester project was set to develop such technology. The prototype comprises two symmetrical harvesters trailed by a farm tractor. Each harvester has a vibratory rotor with flexible rods, a catching platform with conveyors belts delivering fruits to a temporary storage bag. The removal efficiency of canopy shakers are influenced by factors like shaking frequency, ground speed as well as the dimension and shape of olive canopy. In 2014 authors started a trial to evaluate the influence of pruning in olive yield and in the performance of the Side-Row Continuous Canopy Shaking Harvester. The trial was established in an irrigated olive orchard of Picual cultivar planted in 1996 with the array 7 m x 3.5 m. In a randomised complete block design with three replications, four treatments are being compared leading to 12 plots with 30 trees/plot. The treatments under study are: T1—manual pruning using chain saws, in 2014 and 2017; T2—mechanical pruning: topping and hedging the two sides of the canopy, followed by manual pruning complement to remove wood suckers inside the canopy, in 2014 and 2017; T3—mechanical pruning: topping the canopy parallel to the ground and hedging southeast side of the canopy in 2014 and 2017; topping the canopy in July 2015 (summer pruning); hedging northwest side in winter 2016; T4—mechanical pruning: topping and hedging the two sides of the canopy in 2014 and 2017; topping the canopy in July 2015 (summer pruning). Regarding to olive yield per tree, significant differences were found among treatments on different years. However, no significant differences were found regarding the average olive yield per tree, over the period of 2014–2017. Regarding to the olive removal efficiency, only in 2016, significant differences were found among treatments on different years. No significant differences were found regarding the average of the olive removal efficiency, over the period of 2014–2017.

Performance evaluation of lateral canopy shakers with catch frame for continuous harvesting of oranges for juice industry

Citrus is mainly oriented to fresh consumption, and harvesting is usually performed manually. However, the high cost of harvesting and the low availability of labour can compromise the profitability of the crop when it is destined to juice industry. The development of citrus mechanical harvesting for industrial processing is conditioned to reach a high fruit removal efficiency, with a reduced damage to both fruit and trees. The current machines available are very large, requiring extensive plantations with long rows of trees to be efficient. In this study, two lateral canopy shakers equipped with a catch frame were evaluated to harvest independently both sides of the hedge on intensive citrus plantations with the main objective of determining their performance and feasibility. The lateral canopy shakers tested were three tractor-drawn machines, one commercial machine and two prototypes. The tested machines reached a mean value of 78% of fruit removal. Besides, the prototypes, equipped with a catch frame, were able to recover a mean value of 70% of yield. Although the results were promising, for achieving an efficient result, the application of this harvesting technology still requires a process of improvement, and the adaptation of both the machine and the plantation. The machines should reduce the amount of post-harvest ground fruit (5.9%-10.4%). Tree damages generated by the contact of the catch frame with the trunk and the metal rods with main branches were the most relevant. Therefore, it is still necessary to increase the ground speed of the machinery and improving the design of the rods, regulating the rod penetrating deep in the canopy to improve the fruit recovery and limit the damage caused to the trees. Keywords: harvester, mechanical harvesting, fruit removal, tree damage, Citrus sinensis L. Osbeck DOI: 10.25165/j.ijabe.20201303.4998 Citation: Sola-Guirado R R, Castro-Garcia S, Blanco-Roldán G L, Gil-Ribes J A, González-Sánchez E J. Performance evaluation of lateral canopy shakers with catch frame for continuous harvesting of oranges for juice industry. Int J Agric & Biol Eng, 2020; 13(3): 88–93.

The vibration behaviour of hedgerow olive trees in response to mechanical harvesting with straddle harvester

Understanding tree behaviour under mechanical harvesting is very important for orchard management and machine design. The objective of this work is to determine the dynamic response of trees, in a hedgerow arrangement, to a straddle harvester with canopy shaker. Forty-four points were measured in random trees at different heights above the ground. The main vibration parameters in the time and frequency domains were analysed. The transmission range of acceleration between machine rods and trees was 58%, vibrating at a similar frequency of 7.8 Hz. The acceleration values registered in the main direction of rod movement were higher than both in the direction of the hedgerow and vertically. The rods of the harvester are in direct contact with the tree canopy 62% of the tree's vibration time. The resultant acceleration values show a temporal distribution similar to a Gaussian curve but distribution throughout the total vibration time shows that only 49.2% of these values are lower than 50 m s−2 and 93.3% are lower than 300 m s−2. The analysis of vibration time in a range gives more information about the impact of shaking. The tree responded differently at different canopy heights in terms of acceleration RMS and peaks, identifying two zones.

Vibration Monitoring of the Mechanical Harvesting of Citrus to Improve Fruit Detachment Efficiency.

The introduction of a mechanical harvesting process for oranges can contribute to enhancing farm profitability and reducing labour dependency. The objective of this work is to determine the spread of the vibration in citrus tree canopies to establish recommendations to reach high values of fruit detachment efficiency and eliminate the need for subsequent hand-harvesting processes. Field tests were carried out with a lateral tractor-drawn canopy shaker on four commercial plots of sweet oranges. Canopy vibration during the harvesting process was measured with a set of triaxial accelerometer sensors with a datalogger placed on 90 bearing branches. Monitoring of the vibration process, fruit production, and branch properties were analysed. The improvement of fruit detachment efficiency was possible if both the hedge tree and the machinery were mutually adjusted. The hedge should be trained to facilitate access of the rods and to encourage external fructification since the internal canopy branches showed 43% of the acceleration vibration level of the external branches. The machine should be adjusted to vibrate the branches at a vibration time of at least 5.8 s, after the interaction of the rod with the branch, together with a root mean square acceleration value of 23.9 m/s2 to a complete process of fruit detachment.

Fruit abscission pattern of ‘Valencia’ orange with canopy shaker system

Fruit detachment can occur due to natural causes or be mechanically performed by a combination of mechanical stresses that cause tissue breakage in the plant. Forced abscission should not coincide with natural abscission zones (AZ). Abscission zones are very important in citrus harvesting both in terms of the destination market and of the possible damage caused to the tree or fruit. The objective of this study is to determine the abscission pattern of sweet oranges with a canopy shaker and compare it with other detachment systems. Five plots of Valencia oranges were tested during the 2017 and 2018 harvesting seasons, using a commercial tractor-drawn canopy shaker. The diameter, weight and breakage type were evaluated in the cases of natural fall, snap method, mechanical harvesting with canopy shaker, and pull test. Breakage type AZ-C predominated in natural fall (89.0%) and the snap method (79.5%). Similarly, AZ-A predominated for the canopy shaker (58.8%) and pull test (45.3%). Mechanical action on the fruit produced peel tear by breaking the flavedo, which reached highest frequency in the snap method (7.6%). Peel tear breakage required a mean fruit detachment force value of 99.3 N, higher than the average abscission values for AZ-C (88.7 N) and AZ-A (66.6 N). The fruit that remained on the tree after canopy shaker harvesting showed lower mean values of fruit detachment force (16.3%) than the pre-harvest fruit. The frequency of fruit with calyx with the canopy shaker and snap methods was similar, with a mean value of 36%.

Design and evaluation of a two-section canopy shaker with variable frequency for mechanical harvesting of citrus.

Canopy shaking is one of the most commonly used techniques for mechanical harvesting of citrus fruits in orange juice industry. However, tree damage and low harvesting efficiency are the top concerns of growers in adopting the existing harvesting equipment on a large scale. The purpose of this research was to develop a novel canopy shaking system to minimize tree damage and maximize fruit removal for mechanical citrus harvesting. In this study, a two-section canopy shaker composing of top and bottom shaking systems mounted on two rotating drums was proposed and developed. It was configured with two sets of flexible bow-shaped shaking rods in a staggered distribution, which can shake the top and bottom zones of the tree canopy independently. The shaking system was designed based on a linked crank-rocker mechanism. Kinematic simulation analysis was conducted to verify the quick return characteristics and differential properties of this mechanism. Vibration test showed that the frequency of the shaking rod could be adjusted within a range of 1.1-8.8 Hz related to hydraulic motor speeds. The field tests of the shaking system with an average frequency of 4.7 Hz achieved a fruit removal percentage of 82.6% and tree damage rate of 5.4% under a tractor speed of 3 km/h. By contrast, the combined shaking frequency of 4.7 Hz & 4.1 Hz of the canopy shaker produced less tree damage with a percentage of 3.9%. This study indicated that the two-section canopy shaker with an optimized frequency combination could be adaptable to the different zones of the tree canopy, and obtain lower tree damage and higher fruit removal percentage. Keywords: two-section canopy shaker, crank-rocker mechanism, variable frequency, fruit removal percentage, tree damage rate, citrus mechanical harvesting DOI: 10.25165/j.ijabe.20181105.4445 Citation: Pu Y J, Toudeshki A, Ehsani R, Yang F Z. Design and evaluation of a two-section canopy shaker with variable frequency for mechanical harvesting of citrus. Int J Agric & Biol Eng, 2018; 11(5): 77–87.

Innovative circular path harvester for mechanical harvesting of irregular and large-canopy olive trees

The harvesting process of the olive tree is mainly performed by manual means, because traditional olive orchards (the main planting typology) are formed of irregular, large-canopy trees that are very difficult to harvest mechanically. For that reason, the cost of harvesting is very high, and it threatens the future of these plantations whose conversion to other more modern layouts is not always possible due to several limitations. The introduction of a harvester may represent the technological change that is the key factor for improved competitiveness. The main purpose of this work was to develop a harvester based on canopy shaker technology for work on irregular, large trees in a circular path. The design of the harvester was based on a determination of tree geometry, together with tree training. Field tests were used to determine machine-tree interaction, and to evaluate the removal, catch frame and driven systems. The proposed innovation allowed the fully mechanical harvest of previously planted trees with a removal efficiency of over 84%, achieving an effective field capacity of 0.21 hm2/h. Although the results so far have been promising, further improvements are advisable in machine and tree adaptation. Keywords: olive tree, olive fruit, canopy shaker, harvester, machinery design DOI: 10.25165/j.ijabe.20181103.3265 Citation: Rafael R. Sola-Guirado, Gregorio L. Blanco-Roldan, Sergio Castro-Garcia, F.J. Castillo-Ruiz, Jesus A. Gil-Ribes. Innovative circular path harvester for mechanical harvesting of irregular and large-canopy olive trees. Int J Agric & Biol Eng, 2018; 11(3): 86–93.

Vibration analysis of the fruit detachment process in late-season ‘Valencia’ orange with canopy shaker technology

The mechanical harvesting of juice oranges can be achieved by the application of forced vibration to the tree canopy to detach fruit. Among the available harvesting technologies, canopy shaker systems have the advantage of working without stoppages between trees, with rods that penetrate the tree canopy generating low-frequency, high-amplitude movement. The objective of this work is to analyse the fruit detachment process to improve the design and management of canopy shaker systems, reducing the risk of damage to tree and fruit during the mechanical harvesting process. Three different canopy shaker systems were used to remove oranges in a well-adapted intensive orchard during the harvesting period. The fruit detachment process was recorded with a triaxial accelerometer sensor with a datalogger inserted into each tested fruit. Fruit movement displayed a similar frequency value as harvester rods (4.1–4.9 Hz), while the resultant acceleration depended on the interaction of the tree-machine system (38.8–60.4 m s−2). The fruit detachment event occurrence required a vibration time ranging between 1.45 and 5.75 s, which can limit the machine's maximum speed. After the detachment event, fruit presented a short mean time (0.28 s) with no contact with other fruit, branch or machine. The vibration of fruit during the harvesting process was greater, in terms of maximum acceleration, after the detachment event (527.6 m s−2) than before (401.0 m s−2). The use of a catch frame to collect fruit and of padding material in the machinery are fundamental measures to reduce the damage caused to fruit with canopy shaker technologies.

Selection and experimental evaluation of shaking rods of canopy shaker to reduce tree damage for citrus mechanical harvesting

Canopy shaking system is one of the research hotspots for large-scale mechanized fruits harvesting. Shaking rods considered as one of the essential components of canopy shaker are responsible for transferring mechanical energy from shaking mechanism to different regions of tree canopy. This transfer depends on the characteristics of the shaking rods that directly strike the tree canopy. In order to evaluate the effects of the shaking rods on tree damage level and fruit removal percentage, three kinds of shaking rods with different materials or shapes were selected. Based on the results of bending deformation tests, it was proven that the rigid shaking rod (R1) with the material of Polyvinyl Chloride (PVC) did more resistance against producing bending deformation in comparison with the other two types of shaking rods with the material of Polyamide Nylon 12 (PA). By contrast, the position close to the free end of the flexible shaking rod was easier to be deformed by less external force. In addition, dynamic analysis and vibration performance tests indicated that the rigid shaking rod could produce stronger vibration with higher shaking frequency of 4.8 Hz and maximum acceleration of 31.4 m/s2. Finally, the results of field trials indicated that the flexible bow-shaped shaking rod (R3) has a better widespread performance to achieve comparative higher fruit removal percentage up to 82.6% while producing lower tree damage rate of 5.36%. This study demonstrates that the materials or shapes of the shaking rod could significantly influence the fruit detachment rate and tree damage level. This study would provide an essential reference for the application of shaking rods for canopy shaker. Keywords: citrus harvester, shaking rod, canopy shaker, bending deformation, tree damage, fruit removal DOI: 10.25165/j.ijabe.20181102.4126 Citation: Pu Y J, Toudeshki A, Ehsani R, Yang F Z, Abdulridha J. Selection and experimental evaluation of shaking rods of canopy shaker to reduce tree damage for citrus mechanical harvesting. Int J Agric & Biol Eng, 2018; 11(2): 48–54.

Simulation study on the effects of tine-shaking frequency and penetrating depth on fruit detachment for citrus canopy-shaker harvesting

The overall low detachment percentage in citrus mechanical harvesting is a concerning problem. Studies of the effects of tine-shaking frequency and penetrating depth on fruit detachment for citrus canopy-shaker harvesting have not been reported to date. The objective of this study was to examine how tine-shaking frequency and penetrating depth affect fruit detachment based on simulation and pertinent field experiments for a citrus canopy shaker that inserts a row of shaking tines into the tree canopy. According to evaluation of the branch/stem elasticity, density, and fruit detachment force, a cantilevered limb model, including a periodic shaking force, was constructed to simulate the shaking process in citrus canopy shaking. Simulation results demonstrated a positive correlation between the shaking frequency and maximum stress at the fruit end of the stem, and a 5 Hz shaking frequency found to be sufficient for fruit removal. It was also observed that the penetrating depth ensured that, when shaking spot was close to the junction of the limb and stem, the maximum stress increased at the fruit end of the stem. Field trial results agreed with the simulation results, with both simulation and experiments indicating highly significant effects (p < 0.01) from both the tine-shaking frequency and penetrating depth on fruit removal. The simulation method used here can be utilized for improvements in canopy-shaker applications.

Selection and experimental evaluation of shaking rods of canopy shaker to reduce tree damage for citrus mechanical harvesting

Canopy shaking system is one of the research hotspots for large-scale mechanized fruits harvesting. Shaking rods considered as one of the essential components of canopy shaker are responsible for transferring mechanical energy from shaking mechanism to different regions of tree canopy. This transfer depends on the characteristics of the shaking rods that directly strike the tree canopy. In order to evaluate the effects of the shaking rods on tree damage level and fruit removal percentage, three kinds of shaking rods with different materials or shapes were selected. Based on the results of bending deformation tests, it was proven that the rigid shaking rod (R1) with the material of Polyvinyl Chloride (PVC) did more resistance against producing bending deformation in comparison with the other two types of shaking rods with the material of Polyamide Nylon 12 (PA). By contrast, the position close to the free end of the flexible shaking rod was easier to be deformed by less external force. In addition, dynamic analysis and vibration performance tests indicated that the rigid shaking rod could produce stronger vibration with higher shaking frequency of 4.8 Hz and maximum acceleration of 31.4 m/s2. Finally, the results of field trials indicated that the flexible bow-shaped shaking rod (R3) has a better widespread performance to achieve comparative higher fruit removal percentage up to 82.6% while producing lower tree damage rate of 5.36%. This study demonstrates that the materials or shapes of the shaking rod could significantly influence the fruit detachment rate and tree damage level. This study would provide an essential reference for the application of shaking rods for canopy shaker. Keywords: citrus harvester, shaking rod, canopy shaker, bending deformation, tree damage, fruit removal DOI: 10.25165/j.ijabe.20181102.4126 Citation: Pu Y J, Toudeshki A, Ehsani R, Yang F Z, Abdulridha J. Selection and experimental evaluation of shaking rods of canopy shaker to reduce tree damage for citrus mechanical harvesting. Int J Agric & Biol Eng, 2018; 11(2): 48–54.

Shaking Functionality Evaluation of Four Different Types of Citrus Canopy-Shaker Tines

Abstract. The shaking functionality of different types of shaking tines for citrus canopy shakers was evaluated. Shaking responses were simulated using ANSYS/LS-DYNA, and a tractor-mounted experimental shaking machine developed for conducting field trials. Straight nylon, bent nylon, straight PVC, and straight steel tines were used as shaking rods and, in experiments, accelerometers placed at branches and fruit to detect vibrational acceleration. Simulation results indicated that tine materials affected the vibrational response of trees and the acceleration peaks of branches and limbs exerted by a steel tine were ~2.0 times as high as exerted by a nylon tine. Both simulation and experimental results demonstrated that the tine bending stiffness had a positive effect on the generated acceleration. Tree injuries caused by a straight nylon tine were much less than by other tines. The results suggested that a shaking tine should have high stiffness, but its surface should be soft. These simulation and experiment methods can be used for improving canopy shaker applications. Keywords: Citrus harvest, Canopy shaking, Shaking functionality, Trial.

An innovative circular path harvester for mechanical harvesting of irregular, large-canopy olive trees

The harvesting process of the olive tree is mainly performed by manual means, because traditional olive orchards (the main planting typology) are formed of irregular, large-canopy trees that are very difficult to harvest mechanically. For that reason, the cost of harvesting is very high, and it threatens the future of these plantations whose conversion to other more modern layouts is not always possible due to several limitations. The introduction of a harvester may represent the technological change that is the key factor for improved competitiveness. The main purpose of this work was to develop a harvester based on canopy shaker technology for work on irregular, large trees in a circular path. The design of the harvester was based on a determination of tree geometry, together with tree training. Field tests were used to determine machine-tree interaction, and to evaluate the removal, catch frame and driven systems. The proposed innovation allowed the fully mechanical harvest of previously planted trees with a removal efficiency of over 84%, achieving an effective field capacity of 0.21 hm2/h. Although the results so far have been promising, further improvements are advisable in machine and tree adaptation. Keywords: olive tree, olive fruit, canopy shaker, harvester, machinery design DOI: 10.25165/j.ijabe.20181103.3265 Citation: Rafael R. Sola-Guirado, Gregorio L. Blanco-Roldan, Sergio Castro-Garcia, F.J. Castillo-Ruiz, Jesus A. Gil-Ribes. Innovative circular path harvester for mechanical harvesting of irregular and large-canopy olive trees. Int J Agric & Biol Eng, 2018; 11(3): 86–93.

Design and evaluation of a two-section canopy shaker with variable frequency for mechanical harvesting of citrus

Design and evaluation of a two-section canopy shaker with variable frequency for mechanical harvesting of citrus

Automated system for real time tree canopy contact with canopy shakers

Most crops destined for industrial transformation employ mechanical harvesters that have been developed satisfactorily by adapting the tree to the machine features. Not all fruit trees can be adapted, and this is the case in traditional olive orchards, where canopies are very irregular and a complex harvesting system is necessary to adapt to different tree geometries and sizes. Lateral canopy shakers have arisen as an alternative system, the use of which is spreading as they allow continuous integral harvesting of several crops such as citrus fruit or, more recently, the olive. Contact between the shaker and the canopy is a key harvesting factor that must be studied. Manually positioning several shaker heads at different heights to follow the tree contour during continuous harvesting is a tedious task for an operator and may decrease potential efficiency. However, automation of shaker contact with the canopy may increase harvester efficiency. Two automatic systems composed of several electronic devices were developed and incorporated into a harvester with several shaker heads. The first system controlled canopy contact based on measuring the distance between the shaker and the tree contour. The second system measured the variation of the shaker mechanism’s hydraulic pressure in order to adjust the position of each head relative to the canopy. Both systems were compared to manual control by studying removal efficiency, harvesting efficiency, debris production and percentage of shaking time within the control intervals. Results determined the suitability of automatic harvesting systems with an increase of 5.9% in removal efficiency based on the criterion of tree resistance to shaking, with no significant differences in tree damage and an increase in field capacity ha h-1 person-1. Laser LED may be a valid technology for measuring the distance to canopy in real time and gave satisfactory results but a decrease of 7.9% in removal efficiency compared to manual sighting. The bottom, middle and top of the tree present different patterns in the harvesting process, and as resistance mode adjusts control intervals to the different patterns, it may provide a closer fit to follow than distance mode. Further improvements are required to enhance harvesting efficiency by connecting automation between the removal system and the catch frame.

Pruning systems to adapt traditional olive orchards to new integral harvesters

Olive harvesting and pruning are two operations that highly influenced olive growing costs and competitiveness. Both operations should be related to reach an efficient orchard management. Tree structure should be adapted to selected harvesting method, but it also has to be in accordance with tree and orchard features. This research attempts to assess how traditional olives could be adapted to harvesting with canopy shakers, measuring different parameters for pruning and harvester performance. For this purpose, two pruning tests were conducted in 'Picual' and 'Hojiblanca' traditional olive orchards during four years. Three pruning treatments were pruned to adapt tree canopy to different harvesting systems. Harvesting was performed using two different canopy shakers. Harvesting efficiency and debris production were measured as descriptive variables to analyze harvester performance. On the one hand, pruning fresh weight was highly variable between years, however trunk shaker pruning provided higher amount of yearly pruning dry weight while canopy shaker pruning generated higher accumulated pruning dry weight. On the other hand, canopy shaker pruning provided higher harvesting efficiency than other pruning systems for pre-commercial harvester. With regard to debris production, it was highly variable, although it provided significant differences between both cultivars. Finally, pruning and harvesting operations should be related to choose an efficient harvesting system and to adapt the trees to the harvester and vice versa. This rule should be taken into account to carry out an adequate mechanization of an olive orchard.