scholarly journals Estimating Apple Fruit Size Distribution from Early-season Fruit Diameter Measurements

HortScience ◽  
2019 ◽  
Vol 54 (11) ◽  
pp. 1947-1954
Author(s):  
Richard P. Marini ◽  
James R. Schupp ◽  
Tara Auxt Baugher ◽  
Robert Crassweller
Keyword(s):  
Size Distribution ◽  
Fruit Size ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Regression Equations ◽  
Full Bloom ◽  
Actual Distribution ◽  
Early Season ◽  
Large Size ◽  
Fruit Diameter

In three experiments, diameters of apples representing 7% to 30% of the fruit on a tree were measured at ≈60 days after full bloom. Using previously published regression equations, the early-season fruit diameter values were used to estimate apple fruit weight at harvest (FWH). At harvest, all fruit on sample trees were weighed and the distributions of estimated FWH for fruit measured early in the season were compared with distributions of the actual FWH for whole trees. Actual FWH was normally distributed for only one of the three experiments. Although the estimated mean FWH averaged for the 10 trees was within 9% of the actual mean FWH for all three experiments, the distribution of estimated FWH differed significantly from the actual distribution for all three experiments. All fruit were then assigned to appropriate commercial fruit sizes or box counts (number of fruit/19.05 kg). Fruit size tended to peak on the same four box counts for the estimated and actual populations, but the estimated populations had too few fruits in the small- and large-size box counts. Using early-season estimates of FWH, commercial apple growers and packers can predict fairly accurately the percentage of the crop that will fall into the peak box counts, but a more accurate early-season estimate of the fruit size distribution will likely require measuring 50% of the fruit on a tree.

scholarly journals 683 Contributions of Early Season Environment and Crop Load to Apple Fruit Development

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 516D-516
Author(s):  
C.J. Stanley ◽  
D.S. Tustin
Keyword(s):  
Cell Division ◽  
Fruit Size ◽  
Cell Number ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Full Bloom ◽  
Crop Load ◽  
Early Season ◽  
Growth Partitioning ◽  
Load Conditions

Many factors contribute to final apple fruit size. Researchers have studied these factors and have developed models, some very complex. Results from many New Zealand regions over several years suggest that early season temperature along with crop load are the key factors driving final fruit size. Accumulated growing degree days from full bloom to 50 days after full bloom (DAFB), accounted for 90% of the variance in fruit weight of `Royal Gala' apples at 50 DAFB under nonlimiting low-crop-load conditions. In turn, fruit weight at 50 DAFB accounted for 90% of the variance in final fruit size at harvest under the low-crop-load conditions. We hypothesise that a potential maximum fruit size is set by 50 DAFB, determined by total fruit cell number, resulting from a temperature-responsive cell division phase. Under conditions of no limitations after the cell division phase, we suggest that all cells would expand to their optimum size to provide the maximum fruit size achievable for that cell number. Factors which affect growth partitioning among fruits, e.g., higher crop loads, would reduce final fruit size, for any given cell number, when grown in the same environment. In Oct. 1999, four different crop loads were established at full bloom on `Royal Gala' trees (M9 rootstock) in four climatically different regions. In Hawkes Bay, similar crop loads were established at 50 DAFB on additional trees. Hourly temperatures were recorded over the season. Fruit size was measured at 50 DAFB and fruit will be harvested in Feb. 2000. These data should provide fresh insight and discussion into the respective roles of temperature and competition during the cell division fruit growth phase on apple fruit size.

scholarly journals EFFECTS OF HYDROGEN CYANAMIDE ON APPLE AND PLUM FRUIT THINNING

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 690a-690
Author(s):  
Esmaeil Fallahi ◽  
Brenda R. Simons ◽  
John K. Fellman ◽  
W. Michael Colt
Keyword(s):  
Malus Domestica ◽  
Fruit Set ◽  
Fruit Size ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Full Bloom ◽  
Hydrogen Cyanamide ◽  
Fruit Thinning ◽  
Prunus Salicina

Influence of various concentrations of hydrogen cyanamide (HC) on fruit thinning of `Rome Beauty' apple (Malus domestica Borkh.), `Friar,' and `Simka' plums (Prunus salicina Lindley) were studied. A full bloom application of HC at all tested concentrations decreased `Rome Beauty' apple fruit set and yield, and increased fruit weight. Hydrogen cyanamide at 0.25% (V/V) resulted in adequate apple thinning, indicated by the production of an ideal fruit weight. Prebloom and full bloom applications of HC at greater than 0.75% reduced plum fruit set and yield in `Friar.' Full bloom application of HC at 0.25% to 0.50% showed a satisfactory fruit set, yield, and fruit size in `Friar' plum. Full bloom application decreased fruit set and yield in `Simka' plum. Hand thinning, as well as chemical thinning, is recommended for plums.

scholarly journals Effect of Concentration and Time of Accel Application on Cropping of Selected Cultivars

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 765B-765 ◽  
Author(s):  
Jerome Hull ◽  
Martin J. Bukovac ◽  
Brent L. Black
Keyword(s):  
Size Distribution ◽  
Fruit Size ◽  
High Volume ◽  
Fruit Weight ◽  
Yield Reduction ◽  
Early Application ◽  
Time Of Application ◽  
Significant Yield ◽  
Spray Volume ◽  
Fruit Diameter

The effect of Accel concentration and time of application on fruit size and yield was studied using `Delicious' (Redchief), `Empire', `Jonathan', and `Gala'. High-volume sprays of Accel were applied at 25 to 150 mg·liter–1 to `Delicious' and `Empire' at king fruit diameter (KFD) of 5 to 20 mm. `Jonathan' and `Gala' were treated at KFD of 5 to 20 mm with 10 to 40 g/A. The effect of spray volume (500 to 2000 liters·ha–1) and surfactant (Regulaid) was studied using `Jonathan'. Response was indexed by yield and fruit size distribution at harvest. Although yield in `Delicious' was reduced with all concentrations of Accel, the percentage of fruits in the larger-size classes (3”+) was not significantly increased. In contrast, with `Empire', Accel reduced fruit load similar to hand-thinning (HT) and percentage of large fruit equaled or exceeded that of the HT treatment. Increasing concentration of Accel was related to an increase in fruit size; early application (5 mm KFD) was more effective than late (10, 20 mm KFD) application. There was no significant effect of spray volume or Regulaid. Increasing Accel rate (10 to 20 g/A) resulted in significant yield reduction and increase (4% to 9%) in mean fruit weight in `Gala'.

scholarly journals 166 Influence of Crop Level on Growth and Quality of `Braeburn' Apple Fruit

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 418E-419
Author(s):  
P.I. Garriz ◽  
G.M. Colavita ◽  
H.L. Alvarez
Keyword(s):  
Fruit Size ◽  
Growing Season ◽  
Apple Fruit ◽  
Full Bloom ◽  
Cross Sectional ◽  
Crop Load ◽  
Commercial Crop ◽  
Source Sink ◽  
Fruit Diameter

Crop load and the genetic biological carrying capacity (source–sink relationships) determine the potential for fruit size development on apple; however, the environment within which the fruit grows attenuates this potential. The effects of different crop loads on the growth pattern and the progress of maturity in apples were evaluated at the Comahue National Univ., Argentina (lat. 38 56'S long 67 59'W), during the 1998–99 growing season. Our experiment was conducted on 6-year-old `Braeburn'/Malling Merton 111 apple (Malus domestica Borkh.) trees spaced 4.0 × 2.3 m and trained to palmette leader. Treatments were 1) light crop load (LC), 2.5 fruit/cm2 trunk cross-sectional area (TCSA), 2) moderate crop load (MC), 6.5 fruit/cm2 TCSA (standard commercial crop load) and 3) high crop load (HC), minimum 8 fruit/cm2 TCSA, no fruit removed from tree. Whole trees were hand-thinned 19 days after full bloom (DAFB). Fruit diameter (FD) was taken at two weekly intervals (n = 24 per date and treatment) and maturity indexes were determined at harvest. Analysis of variance was used and mean separations were computed with Student's t test. From 38 DAFB until harvest, fruit size was significantly reduced (P < 0.01) in the HC trees, indicating that they were source-limited during growth. At 166 DAFB, FD was 7.48, 7.14, and 6.89 cm for the LC, MC and HC treatments, respectively. Adequate carbon was apparently available to support a commercial crop load since no differences were found between LC and MC trees. Crop level influenced flesh firmness; at 173 DAFB, it was significantly lower in HC trees than MC and LC trees (84.33, 92.51, and 91.57 N, respectively). These results suggest some goals of thinning for ensuring sizable `Braeburn' fruit.

scholarly journals 184 Timing of Benzyladenine Application as a Chemical Thinner of `Empire' Apple

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 455d-455 ◽  
Author(s):  
V. E. Emongor ◽  
D. P. Murr
Keyword(s):  
Fruit Quality ◽  
Ethylene Production ◽  
Fruit Set ◽  
Fruit Size ◽  
Fruit Weight ◽  
Seed Number ◽  
Full Bloom ◽  
Apple Trees ◽  
Effective Time ◽  
Fruit Diameter

Benzyladenine (100 or 200 mg.litre-1) was applied to mature Empire/M.26 apple trees as dilute sprays 2, 4, 9, 11, 13, 15, 17, 20, 25, 27, 29 or 31 days after full bloom (DAFB). The most effective time of thinning was 25-29 DAFB (king fruit diameter 8.94-13.91 mm), and the thinning response to BA concentration was linear. Benzyladenine (BA) did not reduce fruit set when king fruit diameter was less than 5.35 mm, but BA significantly increased fruit weight, diameter (D), length (L) and L:D ratio compared to unsprayed controls and later BA treatments. BA - treated fruitlets had higher ethylene production, 24 hours and 7 days after spraying compared to untreated controls. We suggest that the response of apple fruitlets to BA applied as a thinner is mediated by ethylene. High fruit quality was obtained when BA was applied at 17-31 DAFB. Timing of BA sprays had no effect on seed number, though BA significantly increased seed number, fruit size, weight and L:D ratio. These results suggest that BA has the potential to substitute for the use of carbaryl as a thinner of apples in Ontario orchards.

scholarly journals Sampling Apple Trees to Accurately Estimate Mean Fruit Weight and Fruit Size Distribution

HortScience ◽  
2019 ◽  
Vol 54 (6) ◽  
pp. 1017-1022
Author(s):  
Richard P. Marini ◽  
James R. Schupp ◽  
Tara Auxt Baugher ◽  
Robert Crassweller
Keyword(s):  
Size Distribution ◽  
Fruit Size ◽  
Vertical Axis ◽  
Fruit Weight ◽  
Tree Canopy ◽  
Apple Trees ◽  
True Value ◽  
Vertical Sections ◽  
Fruit Diameter ◽  
Normally Distributed

Canopies of ‘Gala’ and ‘Fuji’ trees, trained to the vertical axis, were divided into eight vertical sections, each representing 12.5% of the tree canopy. The diameter of all ‘Gala’ fruit and fruit weight for all ‘Fuji’ fruit were recorded for each canopy section. Fruit size from most canopy sections was normally distributed and distributions were similar for most sections. Therefore, fruit size distribution for a tree can be estimated by harvesting fruit from two sections of a tree, representing 25% of the canopy. For small trees in intensive plantings, with canopy diameters less than 2.0 m, average fruit diameter or fruit weight estimated from all fruit collected from 25% of the canopy may provide estimates within 7% of the true value.

scholarly journals Physico-chemical characteristics of pomegranate accessions from the Kurdistan region, Iraq

2018 ◽  
Vol 63 (4) ◽  
pp. 355-366
Author(s):  
Saadatian Mohammad ◽  
Paiza Abdurahman ◽  
Kanar Salim ◽  
Pershang Younis ◽  
Hewen Abdurahman ◽  
...  
Keyword(s):  
Fruit Size ◽  
Chemical Properties ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Total Phenolic ◽  
Kurdistan Region ◽  
Fresh Weight ◽  
Fruit Length ◽  
Physico Chemical ◽  
Fruit Diameter

Some physico-chemical properties of ten pomegranate accessions collected from different districts in the Kurdistan region of Iraq were investigated in this paper. Considerable correlations between the characteristics studied were found and valuable pomological traits were observed. Cluster analysis showed the homonyms between some pomegranate accessions. Principle component analysis reported that the component describing the greatest variability also positively correlated with fruit weight, total aril weight, total peel weight, volume of juice, total soluble solids (TSS), fruit length, fruit diameter, pH, aril length, and 100-seed fresh weight, but negatively correlated with titratable acidity (TA). Fruit weight was firmly correlated with total aril weight, total peel weight, volume of juice, TSS, aril length, 100-seed fresh weight, fruit length and fruit diameter. The volume of juice was correlated with TSS, aril length, 100-seed fresh weight, fruit length, fruit diameter and it was observed that with an increase in the fruit size, the volume of juice increased as well. The correlation between total phenolic compounds and antioxidant capacity was not observed. The associations found among physical and chemical traits suggest that consumers should use large fruits with large arils so that they have more juice. Thus, ?Choman?, ?Raniyeh? and ?Halabja? were juicier than other accessions.

Thinning Golden Delicious apples with pre-bloom naphthalene acetic acid and later carbaryl sprays

1984 ◽  
Vol 24 (126) ◽  
pp. 453 ◽  
Author(s):  
KM Jones ◽  
TB Koen ◽  
RJ Meredith
Keyword(s):  
Acetic Acid ◽  
Fruit Size ◽  
Fruit Weight ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Golden Delicious

A trial in southern Tasmania examined the thinning effects of naphthalene acetic acid (NAA) on Golden Delicious apples. The NAA was applied at pink bud or balloon blossom at 12, 18 and 24 ppm, with or without carbaryl at 1800 ppm applied 10 d after full bloom. Carbaryl was also applied alone 10 and 20 d after full bloom, and a hand thinned treatment was included. The higher concentrations of NAA did the most thinning but only the hand-thinned and 24 ppm NAA at balloon blossom with carbaryl treatment thinned enough to produce the required fruit size. The NAA sprays at balloon blossom thinned considerably more than those at pink bud. Neither NAA nor carbaryl alone was as effective as the combination. Reduction of fruit numbers increased mean fruit weight from 101 g in the control to 149 g in the 24 ppm NAA at balloon blossom with carbaryl. There was no evidence that increasing the concentration of NAA reduced mean fruit weight. This trial demonstrates that the effect of balloon stage sprays of NAA combined with later carbaryl sprays on Golden Delicious is similar to that achieved by the normal practice of spraying with NAA 7-14 d after full blossom, followed by carbaryl at 20 d. Reduction from 128 fruit/ 100 blossom clusters in the control to 76 after spraying at balloon blossom is still outside present aims of 30-50 fruit and is not considered to be severe enough thinning to assure adequate fruit size.

Control of pudding spot in Crofton apple

1992 ◽  
Vol 32 (4) ◽  
pp. 503
Author(s):  
KM Jones ◽  
SA Bound ◽  
MJ Oakford ◽  
TB Koen
Keyword(s):  
Acetic Acid ◽  
Fruit Size ◽  
Fruit Weight ◽  
The Other ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Apple Trees ◽  
Low Incidence ◽  
Thinning Effect

Regularly cropped Crofton apple trees in southern Tasmania were thinned using sprays of naphthalene acetic acid (NAA) at 10 mg/L or ethephon at 200 mg/L at balloon blossom (BB), full bloom (FB), 10 days after full bloom (DAFB) or 20 DAFB. These treatments were compared with hand thinning and an unthinned control. Ethephon had a uniformly mild thinning effect (about 30% compared to control), except at 10 DAFB, where no thinning occurred. NAA was inconsistent, thinning well at BB (50%), overthinning at both FB (85%) and 10 DAFB (88%), and underthinning at 20 DAFB (similar to the control). Ethephon applied at BB and FB increased both mean fruit weight (12 and 22%) and fruit size (28 and 79%), but later applications did not. NAA applications generally resulted in increased mean fruit weight and size, except for the 20 DAFB treatment, which was similar to the control. All ethephon treatments had a low incidence (43%) of pudding spot similar to the controls and hand-thinned treatments. Most NAA treatments showed significantly higher levels of pudding spot than the other treatments. It is concluded that ethephon is a more predictable thinner for Crofton than NAA, and its use to control pudding spot is recommended.

scholarly journals Regulating Budbreak, Flowering, and Fruit Maturity in Sweet Cherry (Prunus avium L.) cv. `Bing' by Surfactant and Nitrate Applications

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 603e-603
Author(s):  
K.G. Weis ◽  
S.M. Southwick ◽  
J.T. Yeager ◽  
W.W. Coates ◽  
Michael E. Rupert
Keyword(s):  
Sweet Cherry ◽  
Prunus Avium ◽  
Fruit Set ◽  
Fruit Size ◽  
Calcium Nitrate ◽  
Potassium Nitrate ◽  
Fruit Weight ◽  
Full Bloom ◽  
Fruit Maturity ◽  
Flower And Fruit Development

The years 1995 and 1996 were low chill years in California with respect to stone fruit dormancy. Advancing reproductive budbreak and flowering was accomplished in `Bing' cherry (Prunus avium) by single-spray treatments of a surfactant {a polymeric alkoxylated fatty amine [N,N-bis 2-(omega-hydroxypolyoxyethylene/polyoxypropylene) ethyl alkylamine]} and potassium nitrate in combination when applied at “tightbud,” ≈ 42 days (1 Feb. 1995) before full bloom and with surfactant and potassium nitrate in combination when 10% green calyx was apparent, 33 days before full bloom. Applying 2% surfactant (v/v) + 6% potassium nitrate (w/v) was most effective in advancing bloom, speeding progression through bloom, and advancing fruit maturity when applied at tightbud stage. Surfactant (2% or 4%) applied with 25% or 35% calcium nitrate (w/v) on 2 Feb. 1996 significantly advanced full bloom compared to nontreated controls. Fruit maturity (1995) was somewhat advanced by surfactant–nitrate treatments, but fruit set and final fruit weight were equivalent among treatments. No phytotoxicity was noted in foliage or fruit. In California, marginal and insufficient winter chilling often causes irregular, extended, or delayed bloom periods, resulting in poor bloom-overlap with pollenizers. As a result, flower and fruit development may be so variable as to have small, green and ripe fruit on the same tree, making harvest more time consuming and costly. Data indicate that this surfactant, in combination with a nitrogenous compound, has potential to advance reproductive budbreak and advance maturity in sweet cherry without reducing fruit set or fruit size. Advancing the ripening time of sweet cherry even 2 to 3 days can increase the price received per 8.2-kg box by $10 to $20.

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