scholarly journals String Blossom Thinner Designed for Variable Tree Forms Increases Crop Load Management Efficiency in Trials in Four United States Peach-growing Regions

2010 ◽  
Vol 20 (2) ◽  
pp. 409-414 ◽  
Author(s):  
T. Auxt Baugher ◽  
J. Schupp ◽  
K. Ellis ◽  
J. Remcheck ◽  
E. Winzeler ◽  
...  

Hand thinning is a necessary and costly management practice in peach (Prunus persica) production. Stone fruit producers are finding it increasingly difficult to find a workforce to manually thin fruit crops, and the cost of farm labor is increasing. A new “hybrid” string thinner prototype designed to adjust crop load in vase or angled tree canopies was evaluated in processing and fresh fruit plantings in varying production systems in four U.S. growing regions in 2009. Data were uniformly collected across regions to determine blossom removal rate, fruit set, labor required for follow-up green fruit hand thinning, fruit size distribution at harvest, yield, and economic impact. String thinner trials with the variable tree forms demonstrated reduced labor costs compared with hand-thinned controls and increased crop value due to a larger distribution of fruit in marketable and higher market value sizes. Blossom removal ranged from 17% to 56%, hand thinning requirement was reduced by 19% to 100%, and fruit yield and size distribution improved in at least one string-thinning treatment per experiment. Net economic impact at optimum tractor and spindle speeds was $462 to $1490 and $264 to $934 per acre for processing and fresh market peaches, respectively. Case study interviews of growers who thinned a total of 154 acres indicated that commercial adoption of string-thinning technology would likely have positive impacts on the work place environment.

2020 ◽  
Vol 63 (4) ◽  
pp. 857-863
Author(s):  
Haiqian Xing ◽  
Shaochun Ma ◽  
Ming Liu ◽  
Menglong Wang ◽  
Yi Wei ◽  
...  

HighlightsBoth frequency and amplitude were influencing factors in analyzing the fruit removal efficiency and fruit damage.This research focused on tall spindle ‘Fuji’ apple trees, which enriched the study of the variety and architecture resources of apple trees.The advice for shake-and-catch harvesting was based on the analysis of amplitude and frequency from the perspective of energy consumption.Abstract. Almost all fresh-market apples are picked manually, and these apples rank among the most labor-intensive fruit crops to produce. Due to declining labor supply and rising labor costs, fresh-market apple growers are seeking mechanical harvesting solutions. Shake-and-catch is a potential method that has been well studied. However, because of fruit damage, this method cannot be widely used for fresh-market apples. The primary goal of this study was to investigate how the physical properties of the fruit tree and the shaker parameters affect fruit removal efficiency and fruit damage in an effort to help growers find solutions to the above-mentioned issues. A test system was developed, and its performance was evaluated in certain shaking modes. Based on the experimental results, the physical properties of the tree (length and diameter of limb, length and diameter of twig, and apple weight) and the frequency and amplitude of the shaker influenced the effectiveness of fruit detachment. When the amplitude of the shaker was 14.3 mm and the frequency was less than 15 Hz, the length of the twig had the greatest effect on fruit harvesting. However, with increasing frequency and amplitude, the effect of tree properties on fruit harvesting declined, and amplitude had a more significant effect on fruit harvesting than frequency. Moreover, the fruit removal rate reached 91.43% when the amplitude was 14.3 mm and the frequency was 20 Hz. The results of this study contribute to the development of an effective mechanical harvester that is adapted to tall spindle apple trees. Keywords: Amplitude, Apple fresh market, Frequency, Physical properties, Shake-and-catch, Tall spindle.


2018 ◽  
Vol 28 (1) ◽  
pp. 10-16 ◽  
Author(s):  
R. Karina Gallardo ◽  
Eric T. Stafne ◽  
Lisa Wasko DeVetter ◽  
Qi Zhang ◽  
Charlie Li ◽  
...  

The availability and cost of agricultural labor is constraining the specialty crop industry throughout the United States. Most soft fruits destined for the fresh market are fragile and are usually hand harvested to maintain optimal quality and postharvest longevity. However, because of labor shortages, machine harvest options are being explored out of necessity. A survey on machine harvest of blueberries (Vaccinium sp.) for fresh market was conducted in 2015 and 2016 in seven U.S. states and one Canadian province. Survey respondents totaled 223 blueberry producers of various production sizes and scope. A majority (61%) indicated that their berries were destined for fresh markets with 33% machine harvested for this purpose. Eighty percent said that they thought fruit quality was the limiting factor for machine-harvested blueberries destined for fresh markets. Many producers had used mechanized harvesters, but their experience varied greatly. Just less than half (47%) used mechanical harvesters for fewer than 5 years. Most respondents indicated that labor was a primary concern, as well as competing markets and weather. New technologies that reduce harvesting constraints, such as improvements to harvest machinery and packing lines, were of interest to most respondents. Forty-five percent stated they would be interested in using a modified harvest-aid platform with handheld shaking devices if it is viable (i.e., fruit quality and picking efficiency is maintained and the practice is cost effective). Overall, the survey showed that blueberry producers have great concerns with labor costs and availability and are open to exploring mechanization as a way to mitigate the need for hand-harvest labor.


Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 245
Author(s):  
Yixin Cai ◽  
Fumiomi Takeda ◽  
Brian Foote ◽  
Lisa Wasko DeVetter

Machine harvesting blueberry (Vaccinium sp.) alleviates labor costs and shortages but can reduce fruit quality. Installation of softer catching surfaces inside modified over-the-row harvesters (modified OTR) and adjusting harvest intervals may improve fruit quality and packout. The objective of this study was to determine the effect of harvest interval on fruit quality of fresh market northern highbush blueberry (Vaccinium corymbosum L.) harvested using a modified OTR. ‘Liberty’ blueberry bushes were harvested by hand or using a modified OTR at 3-, 10-, and 14-day intervals in 2019 and at 7-, 11-, and 14-day intervals in 2020. Hand-harvested ‘Liberty’ had greater packout and firmness than machine-harvested fruit. Machine harvesting at the 3-day interval in 2019, and the 14-day interval in 2020 reduced packout from 70–80% to 60% and 54%, respectively. In 2019, machine harvesting at a 3-day interval overall resulted in fruit with greater firmness, higher titratable acidity (TA), and lower total soluble solids (TSS) and SS/TA, compared to other harvest intervals. In 2020, the 7-day machine-harvest interval had a greater TA and lower TSS/TA, compared to the 11- and 14-day intervals. Overall, modified OTR machine-harvest intervals can be extended to 10–11 days for fresh market northern highbush cultivars such as ‘Liberty’ grown in northwest Washington.


HortScience ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 239-245 ◽  
Author(s):  
Gabino H. Reginato ◽  
Víctor García de Cortázar ◽  
Terence L. Robinson

Several field experiments to assess the effect of tree size and crop load on fruit size and yield efficiency were conducted in cling peach and nectarine orchards of different harvest seasons in Chile. Trees were randomly selected in each orchard and then hand-thinned at the beginning of pit hardening to a wide range of crop loads. The fraction of above-canopy photosynthetically active radiation (PAR) intercepted by the canopy (PAR i) was determined at harvest. All fruits were counted and weighed and average fruit weight calculated. Crop load and yield were normalized by tree size measured by intercepted PAR i. For each orchard, the relationship between crop load and fruit size or crop load and yield efficiency was assessed by regression analysis. Fruit size distribution was calculated from fruit size adjusted for fruit load assuming a normal fruit size distribution and valued according to shipment date and price obtained from a Chilean export company. Using crop load as a covariate, fruit size adjusted for crop load was compared for nectarine and peach cultivars. Fruit size adjusted for fruit load and yield efficiency was greater with late season cultivars than the early or midseason cultivars. Predicted crop value (PCV), normalized in terms of PAR intercepted, was calculated for all the cultivars. Large differences in predicted crop value were found for early, midseason, and late ripening nectarines. Early and late ripening cultivars had the highest predicted crop value, especially at lower crop loads and larger fruit sizes. The early season cultivars had high crop value as a result of higher fruit prices, whereas the late season cultivar had high crop value as a result of higher production. With cling peaches, the early season cultivar ‘Jungerman’ had a lower predicted crop value than the late season cultivars ‘Ross’ and ‘Davis’. For cling peaches, the highest PCV was achieved at a relatively high crop load with high yield and small fruit size.


2011 ◽  
Vol 21 (5) ◽  
pp. 593-598 ◽  
Author(s):  
Tyler G. Berkey ◽  
Anna Katharine Mansfield ◽  
Steven D. Lerch ◽  
James M. Meyers ◽  
Justine E. Vanden Heuvel

Crop load management treatments were applied to ‘Seyval Blanc’ grapevines (Vitis hybrid) as a 2 × 2 factorial design: no shoot thinning (ST)/no cluster thinning (CL) (i.e., control), ST combined with CL (ST + CL), ST only, and CL only. All treatments reduced yield and crop load (yield/pruning weight) in 2009 and had a smaller impact in 2010 due to the carryover effect of previous year treatments on crop potential. Soluble solids were improved by up to 3.2% by the ST + CL treatment in 2009, but were not impacted by treatments in the second year when the range of yield was smaller and the ripening conditions more favorable. Rank sum analysis for the 2009 vintage indicated that wines produced from the CL treatment were preferred by the sensory panel compared with the control wine, but there were no differences in consumer preference for wines produced in the 2010 season. Grower preferred price in 2009 (required to compensate the grower for labor costs and lost yield) increased from $556/t in the control to $824/t in the CL treatment, an increase which could be justified by the demonstrated consumer preference for the CL wine. Grower preferred price was $1022/t in the ST + CL treatment in 2009, a price increase that was not justified by a demonstrated consumer preference for the wine. In 2010, grower preferred price ranged from $541/t for the control to $610/t for the ST + CL treatment, an unjustified increase based on the lack of demonstrated consumer preference for the wines.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1147c-1147
Author(s):  
J. Anthony Hopfinger ◽  
Donald W. Shaffner ◽  
Eric D. Cubberley

Both Cacl2 and Nutrical (a trihydroxyglutarate chelate) were foliarly applied at rates of 1.8 and 5.5 Cacl2/ha/season and 1.5 and 4.5 l/ha/season, respectively. Applications were made starting at shuck split and repeated at 2 week intervals until harvest. Neither calcium treatment had an effect on fruit size and size distribution. Fruit size was directly related to crop load. Calcium chloride application had the most pronounced effect on increasing the red over-color of `Cresthaven' peaches with Nutrical intermediate compared to the control. The high rate of Nutrical increased flesh calcium levels at harvest by 75-100 PPM. Instron Texture Profile Analysis indicated that any calcium treatment significantly increased the hardness of the peach. Nutrical at 4.5 l/ha/season improved hardness 2-fold compared to the controls. The improved hardness was maintained throughout the 6 week storage period.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1122e-1122
Author(s):  
B. D. Horton

Cultivars of fresh market peaches (Prunus persica, L. Batsch) vary in the duration for maximum yields in the shipping stage (firm ripe) from once-over harvests. A cultivar having many firm ripe fruit with few green and over ripe at a given time has a narrow maturity range. It can be picked fewer times, facilitate mechanical once-over harvests and reduce spray costs. Fruit were harvested from small trees or scaffold branches of large trees at 2- to 3-day intervals as once-over harvests on 4 dates to estimate maturity range and duration of the maximum firm ripe fruit. Fruit of 3 cultivars were graded by color into maturity stages: 1) green, 2) firm ripe, and 3) over ripe. `Loring' had 82% firm ripe sorted in the 1st 3 harvests in 1987 and 1988. `Redskin' had 83% firm ripe in the 2nd and 3rd harvests in 1987. `Redglobe' had 85% marketable in the 2nd and dropped to 75% in the 3rd harvest in 1987. `Redhaven' had about 80% firm ripe in the 1st 3 harvests in 1988. Results indicate that the duration of narrow maturity ranges of `Loring' and `Redhaven' would permit them to be harvested over about 5 days with high yieids in the firm-ripe stage.


2017 ◽  
Vol 9 (1) ◽  
pp. 332-337
Author(s):  
Rimpika Rimpika ◽  
N. Sharma ◽  
D.P. Sharma

The present investigation was carried out on 12-year old trees of nectarine (Prunus persica (L.) Batsch var. nucipersica) cultivar May Fire raised on wild peach seedling rootstocks, Farmer’s orchard at Kotla- Barog in District Sirmour during the years 2014 and 2015. In this experiment, experimental trees were subjected to seventeen different treatments;T1: Pruning to retain 60 fruiting shoots tree-1 (control), T2: Pruning to retain 50 fruiting shoots tree-1, T3: Pruning to retain 40 fruiting shoots tree-1 ,T4: NAA 40 ppm, 2 WAPF (week after petal fall) ,T5: Ethrel 300 ppm, 2 WAPF, T6: GA3 100 ppm, 4 WAPF, T7: GA3 200 ppm, 4WAPF, T8: GA3 100 ppm, 6 WAPF T9: GA3 200 ppm, 6 WAPF, T10: Pruning to retain 50 fruiting shoots tree-1 + NAA 40 ppm (T4), T11: Pruning to retain 50 fruiting shoots tree-1 + Ethrel 300ppm (T5), T12: Pruning to retain 50 fruiting shoots tree-1 + GA3100 ppm (T6), T13: Pruning to retain 50 fruiting shoots tree-1 + GA3 100 ppm (T8),T14: Pruning to retain 40 fruiting shoots tree-1 + NAA 40 ppm (T4), T15: Pruning to retain 40 fruiting shoots tree -1 +Ethrel 300 ppm (T5),T16: Pruning to retain 40 fruiting shoots tree -1 + GA3 100 ppm (T6), T17: Pruning to retain 40 fruiting shoots tree -1 + GA3 100 ppm (T8), pertaining to alternative approach to chemical thinning, chemical thinner were more effective in improving the production of superior grade fruits than reducing the crop load directly by pruning or indirectly by GA 3 (Gibberellic Acid) treatments. Treatments with NAA (naphthalene acetic acid) at 40 ppm when applied two weeks after petal fall reduced the crop load to the greatest extent and improve the yield of superior grade fruits and increase the leaf to fruit ratio and decrease the fruit drop. Pruning to retain 40 fruiting shoots tree-1 + NAA 40 ppm, 2WAPF increased the shoot growth (160.80, 170.20cm), tree height (3.70,4.50 cm), tree spread (2.84,3.60), leaf area (42.71, 40.63 cm) during both the year. However, effect of chemical were less pronounced on trees subjected to severe pruning.


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 561F-562
Author(s):  
Stephen M. Southwick

Commercially grown apricots (Prunus armeniaca), peaches (Prunus persica), nectarines (Prunus persica), plums (Prunus salicina and Prunus domestica), and pluots (Prunus salicina × Prunus armeniaca) have a tendency to produce high numbers of flowers. These flowers often set and produce more fruit than trees can adequately size to meet market standards. When excessive fruit set occurs, removal of fruit by hand-thinning is common to ensure that fruit size meets market standards. Over the years there have been numerous attempts to find chemical or physical techniques that would help to reduce costs associated with and improve efficiencies of hand-thinning; however, using alternate strategies to hand-thinning have not been widely adopted in stone fruit production. In the past 10 years, through the continuing efforts of scientists throughout the world in public and private institutions and business, it appears that there are chemical sprays capable of reducing the need for hand-thinning in stone fruit. Management of flowering by reducing the number of flowers on apricot, peach, nectarine, plum, and prune has shown promise under climatic conditions such as those found in the San Joaquin Valley of California. By applying gibberellins during May through July, flowers in many stone fruit cultivars can be reduced in the following season. The reduction in flower number does not generally lead to an increase in fruit set. As a result, fruit numbers are reduced, the need for hand thinning can be reduced, and in some cases eliminated. There are risks associated with reducing flower number before climatic conditions during bloom or final fruit set are known. However, given the changes in labor costs and market demands, especially in the developed world, the benefits may outweigh the risks. The application and implications of these summer gibberellin applications toward reducing flower numbers will be discussed as it relates to commercial stone fruit growing.


HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 512-514 ◽  
Author(s):  
Richard P. Marini

Mature `Norman'peach [Prunus persica (L.) Batsch] trees were dormant pruned to retain a range of fruiting shoots per tree (71 to 250) during 3 years from 1997 to 1999. About 40 days after bloom each year, fruits on all trees were thinned to similar crop loads, so only the number of fruits per shoot varied. Fruit set and number of fruits removed by hand thinning were positively related to number of fruiting shoots retained per tree. Number of fruits harvested per tree was not related to number of shoots per tree, whereas average fruit weight at thinning and at harvest, and crop value per tree were negatively related to the number of shoots retained per tree. These results indicate that commercial peach producers should consider modifying pruning and thinning strategies. Rather than retaining a large number of fruiting shoots per tree and hand thinning to distribute fruits every 15 to 20 cm along each fruiting shoot, producers should first determine the number of fruits that trees of a given cultivar can adequately size and then perform the thinning operation to obtain the desired crop load. The number of fruiting shoots retained per tree during pruning should be one-fifth to one-seventh of the number of fruits desired per tree, so that five to seven fruits per fruiting shoot are retained after hand thinning.


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