Of the 193,000 ha of sweet oranges [ Citrus sinensis (L.) Osbeck] grown commercially for juice in Florida ( Anonymous, 2008 ), 12,153 ha or ≈7% are mechanically harvested ( Florida Department of Citrus, 2008 ). The most common mechanical
Robert C. Ebel, Jacqueline K. Burns, Kelly T. Morgan and Fritz Roka
Kelly T. Morgan, Smita Barkataky, Davie Kadyampakeni, Robert Ebel and Fritz Roka
). Advantages of mechanical harvesting include reduced harvesting costs by 20 to 40 cents per box, which reduces the dependence on seasonal laborers thereby making the harvesting procedure relatively easier and cost-effective. In the past 50 years, there has
Ana Morales-Sillero, Pilar Rallo, María Rocío Jiménez, Laura Casanova and María Paz Suárez
as 69% of the total direct eligible costs. This has led to the removal of a considerable number of olive groves and to the development of mechanical harvesting methods in traditional table olive farms ( Ferguson et al., 2010 ; Rallo et al., 2013a
Jim E. Wyatt
Removing a portion of the foliage of zucchini squash without reducing yield would increase the efficiency of mechanical harvest since less plant material would be passed through the harvester. Pruning 50% of the leaves and petioles at either first or second harvest had no effect on third harvest fruit yield. Primary or secondary fruit growth rates were not affected by leaf removal. Presence of a primary fruit reduced the number of secondary fruit developing to marketable size but the rate of secondary fruit development was similar on plants with one, two, or three fruit. The maximum fruit to develop at one time in this planting was two per plant. Following one or two hand-harvests of zucchini squash, mechanical harvest efficiency will be increased after removal of 50% of the leaves and maturation of two marketable fruit per plant.
Juan Carlos Melgar, Jill M. Dunlop, L. Gene Albrigo and James P. Syvertsen
Successful mechanical harvesting of perennial fruit crops requires efficient, economical harvesting systems that do not shorten a tree's productive life or diminish fruit quality relative to hand harvesting ( Roka et al., 2000 ). Although most of
D.M. Glenn, D.L. Peterson and S.S. Miller
This study evaluated the total and marketable yield of three peach cultivars [Prunus persica (L.) Batsch. `Autumnglo', `Harvester', and `Redhaven'] when mechanical pruning and harvesting systems were used and trees were grown under three irrigation regimes. All cultivars were trunk-shaken using an experimental inertial shaker on an over-the-row (OTR) shake–catch harvester. `Autumnglo' also was hand-harvested at all irrigation regimes. Fruit damage was not significantly affected by irrigation. A significant source of fruit damage was pruning debris that remained in the canopy after hedging and became lodged in the fruit-conveying system, resulting in cultivar effects on fruit damage. Total yield of firm-ripe fruit was similar among cultivars in 1987 and 1988. However, `Autumnglo' trees had a higher percentage of marketable fruit than `Redhaven' or `Harvester' in 1987 and 1991. Mechanical harvesting appeared to accelerate the decline of `Autumnglo' as shown by tree deaths and greater symptom expression of Prunus necrotic ringspot virus. The potential for a single mechanical harvest of peaches is limited because of the difficulty in managing the ripening window, the high potential for fruit damage, and the possibility of accelerated tree decline for disease-susceptible cultivars.
B. Buckley, W.A. Mulkey, J.D. Griffins, K.C. Peel, T. Talbota and W. Russell
Four southernpea cultivars were evaluated for fresh market mechanical harvest at Calhoun, Chase, and Ruston, Louisiana. The cultivars were 'Encore', 'Royal Cream', 'Queen Anne', and 'Texas Pinkeye'. In addition, 'Early Acre' and breeding lines AR87-435 and AR91-135 were also evaluated at Chase. The marketable yield from mechanical harvest ranged from 1075 kg·ha-1 for 'Royal Cream' at Calhoun and Ruston to 1855 kg·ha-1 for 'Encore' at Calhoun and Chase. Low concentrated maturity was the main factor limiting marketable yield. The percent mature pods at harvest was near 55 for most cultivars. Yield efficiency of mechanical harvest vS. hand harvest was above 75% for most cultivars. The percent trash resulting from machine harvest ranged from 6 for AR91-135 to 24 for 'Queen Anne'.
Mechanically harvested pickling cucumbers are a once-over destructive harvest system. Gynoecious hybrids are planted at high populations to obtain high yields and to concentrate maturity. Population, row width, plant spacing, and uniform emergence all affect yield and maturity. 65,000 plants/acre in 26 inch rows were found to optimize yield and provide the highest percentage of fruit at the desired uniform size.
Juan Carlos Melgar, Jill M. Dunlop and James P. Syvertsen
Mechanical harvesting of citrus fruit for juice processing from large-scale commercial plantings in Florida has economic advantages ( Roka et al., 2008 ) over hand-harvesting, especially when adequate seasonal labor is not available ( Brown, 2005
Kuo-Tan Li* and James P. Syvertsen
Mechanical harvesting of citrus trees by trunk or canopy shakers can cause leaf and twig removal, bark injury and root exposure. Such problems have restricted the adoption of mechanical harvesting in Florida citrus. We assessed physiological responses of citrus trees that were mechanically harvested with a linear-type trunk shaker, operating at 4 Hz, 70.8 kg mass weight, and 6.5 cm displacement, for 10 or 20 seconds. We measured fruit recovery efficiency, leaf and shoot removal, mid-day stem water potential, leaf gas exchange, and leaf fluorescence emission of mature `Hamlin' and `Valencia' orange trees under restricted or normal irrigation. Shaking treatments effectively removed 90% to 94% of fruit without bark damage. Compared to harvesting by hand, trunk shaking removed 10% more leaf area and twigs, and caused some visible exposure of fibrous roots at the soil surface. There were no significant treatment differences on mid-day stem water potential, leaf gas exchange, and leaf photosystem efficiency. Excessively shaken trees for 20-30 seconds can temporary induce stress symptoms resembling that in trees without irrigation. Trees may have benefited from the low levels of leaf and twig loss after trunk shaking that compensated for any root loss. Long-term effects of trunk shaking will be assessed by tree growth, return bloom, subsequent yield, and carbohydrate reserves.