Mechanical Harvesting Capacity in Sweet Orange Is Increased with an Abscission Agent

Burns, J. C.; Buker, Richard S.; Roka, Fritz

doi:10.21273/horttech.15.4.0758

Cited by 23 publications

(20 citation statements)

References 10 publications

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“…For all of the fruit removal percentages, the mean values under three different driving speeds had similar trends that higher shaking frequencies could remove more fruits, which agree with previous studies reported by Hong et al [27] and Castro-Garcia et al [44] , but the fruit removal percentage changed slightly when the shaking frequency reached 4.7 Hz. Additionally, it was observed that the fruit removal percentage at lower driving speed could be higher, which is similar to the results of previous studies that reasonable shaking duration produces more fruit removal [40,41,45,46] . Shamshiri et al [39] also pointed out that the reduction of driving speed has a negative effect on the efficiency of the harvester and may make uneconomical mechanical harvesting.…”

Section: Fruit Removal and Tree Damage Evaluation 431 Effects Of Shsupporting

confidence: 89%

“…The shaking rod deformation characteristics are not within the scope of this study, but its shaking response could potentially relate to the variable frequency and amplitude [36] . Due to ineffective shaking for fruits harvesting under a low shaking frequency, which has been observed by Ortiz and Torregrosa [41] , all of the subsequent field trials for harvesting efficiency and tree damage assessment were performed with the shaking frequency range from 3.3 Hz to 6.8 Hz, which has been recommended for canopy shakers [45] .…”

Section: Performance Test Of the Shaking Systemmentioning

confidence: 99%

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

Toudeshki

Ehsani

et al. 2018

International Journal of Agricultural and Biological Engineering

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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. 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.

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Section: Fruit Removal and Tree Damage Evaluation 431 Effects Of Shsupporting

confidence: 89%

Section: Performance Test Of the Shaking Systemmentioning

confidence: 99%

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

Toudeshki

Ehsani

et al. 2018

International Journal of Agricultural and Biological Engineering

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“…Mechanical harvesting is often associated with significant losses such as ground loss (20%), mechanical injury to the berries and the plant, removal of immature fruit, and decline in the postharvest quality of the fruit (Takeda et al, 2008;van Dalfsen and Gaye, 1999). The application of fruit-loosening agents that can decrease the force required for fruit detachment can contribute greatly toward enhancing the efficiency of mechanical harvesting (Burns, 2002;Burns et al, 2005).…”

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confidence: 99%

Ethephon and Methyl Jasmonate Affect Fruit Detachment in Rabbiteye and Southern Highbush Blueberry

Malladi¹,

Vashisth²,

Johnson³

2012

horts

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Two abscission agents, ethephon and methyl jasmonate, were investigated in five studies to determine their potential for increasing fruit detachment during harvest in rabbiteye (Vaccinium ashei Reade) and southern highbush (hybrids based largely on Vaccinium corymbosum L. and Vaccinium darrowi Camp.) blueberry. In the first study with a rabbiteye blueberry genotype, T-451, ethephon applications up to 1000 mg·L−1 did not affect fruit drop but reduced fruit detachment force (FDF) by up to 21%. In the second study with two southern highbush blueberry genotypes, ethephon (up to 1500 mg·L−1) and methyl jasmonate (MeJa; up to 10 mm) applications resulted in significant fruit drop in ‘Star’ but neither of the growth regulators affected the fruit detachment characteristics of ‘Farthing’. In a third study with rabbiteye blueberry genotypes, MeJa applications of 10, 20, and 30 mm displayed an increasing linear trend in fruit drop in ‘Climax’ and linear and quadratic trends in fruit drop in ‘Powderblue’. In a fourth study with ‘Powderblue’, MeJa (20 mm) and ethephon (1000 mg·L−1) applications resulted in rapid and significant fruit drop. The fruit drop induced by MeJa in this study was attenuated by the coapplication of aminoethoxyvinylglycine (AVG), an ethylene biosynthesis inhibitor, suggesting that MeJa induced fruit detachment partly through its effects on ethylene biosynthesis. In another study with the southern highbush blueberry genotype, O’Neal, MeJa applications (20 mm) induced significant fruit drop but ethephon (1000 mg·L−1) applications did not affect fruit detachment. Overall, MeJa applications (20 mm or greater) generally induced rapid and extensive fruit abscission, often within 1 day after treatment. Applications of MeJa resulted in leaf yellowing and necrosis of leaf tips and margins, especially at high rates of application (20 mm or greater). Ethephon applications resulted in the abscission of mature and immature berries. Both ethephon and MeJa applications resulted in the detachment of the pedicel along with the fruit. Together, these data suggest that although ethephon and MeJa have the potential to be used as harvest aids in blueberry, the rates of application require further optimization to minimize potential phytotoxicity. Additionally, effective de-stemming of the berries may be essential if these compounds are to be used as harvest aids.

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“…Due to increasing labor costs, the use of mechanical technologies to harvest Florida processing oranges is steadily increasing. Successful mechanical harvesting of orange fruit is enhanced by the use of abscission agents that reduce fruit detachment force and increase the effi ciency of fruit removal during mechanical harvesting (Burns, 2002;Burns et al, 2005). However, most abscission agents not only loosen fruit but also cause leaf abscission (Burns et al, 2003b).…”

mentioning

confidence: 99%

Partial Defoliation Can Decrease Average Leaf Size but Has Little Effect on Orange Tree Growth, Fruit Yield and Juice Quality

Yuan¹,

Alférez²,

Kostenyuk³

et al. 2005

HortSci

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The effects of 2 consecutive years of annual defoliation during the harvest season on fruit size, yield, juice quality, leaf size and number were examined in trees of the midseason cultivar `Hamlin' and the late-season cultivar `Valencia' orange [Citrus sinensis (L.) Osb.]. In `Hamlin', removal of up to 50% of the leaves in late November had no effect on fruit yield, fruit number, fruit size, soluble solids yield, juice °Brix, and °Brix to acid ratio of juice the following year. In `Valencia', removal of 50% of the leaves in late March decreased fruit yield and soluble solids yield but did not affect Brix or the Brix to acid ratio of the juice. Leaf size of new flush was reduced by removal of 50% of the leaves in both cultivars but there was little effect on total canopy size. There were no measured effects of removing 25% of leaves from tree canopies. Thus, canopy growth, fruit yield, fruit quality, and leaf size were not negatively impacted when annual defoliations did not exceed 25% of the total canopy leaf area in `Valencia' and `Hamlin' orange trees for two consecutive years. Overall, fruit weight increased linearly with increasing ratio of leaf area to fruit number, suggesting that fruit enlargement can be limited by leaf area.

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Mechanical Harvesting Capacity in Sweet Orange Is Increased with an Abscission Agent

Cited by 23 publications

References 10 publications

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

Ethephon and Methyl Jasmonate Affect Fruit Detachment in Rabbiteye and Southern Highbush Blueberry

Partial Defoliation Can Decrease Average Leaf Size but Has Little Effect on Orange Tree Growth, Fruit Yield and Juice Quality

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