scholarly journals Thinning Tall Spindle Apple Based on Estimations Made With a Hand-thinning Gauge

2013 ◽  
Vol 23 (6) ◽  
pp. 830-835 ◽  
Author(s):  
Thomas M. Kon ◽  
James R. Schupp
Keyword(s):  
Branch Length ◽  
Fruit Weight ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Adjustment Factor ◽  
Cross Sectional ◽  
Crop Load ◽  
Crop Density ◽  
Whole Tree ◽  
June Drop

Trials were conducted in 2009 and 2010 to evaluate the use of a hand-thinning gauge [Equilifruit; Institut National de la Recherche Agronomique (INRA), Montpelier, France] on three cultivars of apple (Malus ×domestica) trees trained to tall spindle. Hand-thinning treatments were applied after June drop to trees with supra-optimal crop loads. Three hand-thinning treatments were applied using the hand-thinning gauge: 1) thinning to ≈6 fruit/cm2 branch cross-sectional area (BCSA) (F value), 2) subtracting the delta value [Δ (an adjustment factor to increase or decrease the number of fruit per BCSA] from the F value (F − Δ), and 3) F − 2Δ. These treatments were compared with a control and a traditional hand-thinning heuristic of spacing a solitary fruit every 7 to 8 inches of branch length. Use of the hand-thinning gauge generally improved fruit weight and maintained whole tree yields when compared with the control. Hand-thinning based upon traditional fruit-spacing heuristics reduced crop density and increased final fruit weight of apple, but significant reductions in yield were observed in two of four studies when compared with the control. We find the hand-thinning gauge a useful tool in adjusting final crop load of apple.

scholarly journals Cropping Efficiency of Young `Fuji' Apple Trees

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 886A-886
Author(s):  
Preston K. Andrews ◽  
Margaret L. Collier
Keyword(s):  
Vegetative Growth ◽  
Fruit Size ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Apple Trees ◽  
Cross Sectional ◽  
Crop Load ◽  
Previous Season ◽  
Crop Density ◽  
Fuji Apple

Effects of crop load and time of thinning on productivity of young `Fuji'/M.9 apple trees were tested by hand blossom (B) or fruit (F) thinning to two crop densities (fruit number/trunk cross-sectional area). Heavy (H) crop densities resulted in higher yields in both 2nd and 3rd leaf than light (L) crop densities. Time of thinning had no effect on yields in either year. In the 2nd leaf, fruit size was largest from trees B thinned to L crop densities, and smallest from trees F thinned to either crop density from mid-June through harvest. Both 1° and 2° vegetative growth were greatest in noncropped trees, intermediate in trees with L crops, and least in trees with H crops. Noncropped 2nd-1eaf trees had the highest flowering indices (flower clusters/100 total buds) the following spring and H cropped trees had the lowest. The flowering index was higher when trees were B thinned in the 2nd leaf than when F thinned. In the 3rd leaf, fruit size was largest when borne on weak upright shoots, intermediate on spurs, and smallest on 1-year-old terminal wood. Fruit on spurs had the highest incidence of sunscald (17%) and fruit on weak upright shoots the lowest (8%). Previous-season crop densities affected current-season's vegetative and fruit growth.

scholarly journals A Statistical Model to Estimate Potential Yields in Peach before Bloom

2003 ◽  
Vol 128 (3) ◽  
pp. 297-301 ◽  
Author(s):  
Carlos Miranda Jiménez ◽  
J. Bernardo Royo Díaz
Keyword(s):  
Prunus Persica ◽  
Predictive Ability ◽  
Frost Damage ◽  
Fruit Weight ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Potential Yield ◽  
Cross Sectional ◽  
Yield Efficiency ◽  
Crop Density

Spring frosts are usual in many of Spain's fruit-growing areas, so it is common to insure crops against frost damage. After a frost, crop loss must be evaluated, by comparing what crop is left with the amount that would have been obtained under normal conditions. Potential crop must be evaluated quickly through the use of measurements obtainable at the beginning of the tree's growth cycle. During the years 1997 through 1999 and in 86 commercial plots of peach and nectarine [Prunus persica (L.) Batsch], the following measurements were obtained: trunk cross-sectional area (TCA, cm2), trunk cross sectional area per hectare (TCA/ha), estimated total shoot length per trunk cross-sectional area (SLT, shoot m/cm2 TCA), crop density (CD, amount of fruit/cm2 TCA), fruit weight (FW, g), yield efficiency (YE, kg of fruit/cm2 TCA), yield per tree (Y, kg fruit/tree) and days between full bloom and harvest (BHP, days). CD and average FW were related to the rest of the variables through the use of multiple regression models. The models which provided the best fit were CD = SLT - TCA/ha and FW = SLT + BHP - CD. These models were significant, consistent, and appropriate for all three years. The models' predictive ability was evaluated for 32 different plots in 2001 and 2002. Statistical analysis showed the models to be valid for the forecast of orchards' potential yield efficiency, so that they represent a useful tool for early crop prediction and evaluation of losses due to late frosts.

scholarly journals Statistical Model Estimates Potential Yields in `Golden Delicious' and `Royal Gala' Apples before Bloom

2004 ◽  
Vol 129 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Carlos Miranda Jiménez ◽  
J. Bernardo Royo Díaz
Keyword(s):  
Frost Damage ◽  
Fruit Weight ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Land Area ◽  
Flower Buds ◽  
Cross Sectional ◽  
Crop Density ◽  
Golden Delicious ◽  
Flower Density

Spring frosts are usual in many of Spain's fruit-growing areas, so it is common to insure crops against frost damage. After a frost, crop loss must be evaluated, by comparing what crop is left with the amount that would have been obtained under normal conditions. Potential crop must be evaluated quickly through the use of measurements obtainable at the beginning of the tree's growth cycle. During the years 1998 and 1999 and in 62 commercial plots of `Golden Delicious' and `Royal Gala' apple (Malus ×domestica Borkh.), the following measurements were obtained: trunk cross-sectional area (TCA, cm2), space allocated per tree (ST, m2) trunk cross-sectional area per hectare (TCA/ha), flower density (FD, number of flower buds/cm2 TCA), flower density per land area (FA, number of flower buds/m2 land area), cluster set (CS, number of fruit clusters/number of flower clusters, percent), crop density (CD, number of fruit/cm2 TCA), fruit clusters per trunk cross-sectional area (FCT, number of fruit clusters/cm2 TCA), fruit clusters per land area (FCA, number of fruit clusters/m2 land area), fruit number per cluster (FNC), average fruit weight (FW, g), average yield per fruit cluster (CY, g), yield efficiency (YE, fruit g·cm-2 TCA), and tree yield (Y, fruit kg/tree). FCT and average CY were related to the rest of the variables through the use of multiple regression models. The models which provided the best fit were FCT = FD - TCA/ha - FD and CY= -FCA - FCT. These models were significant, consistent, and appropriate for both years. Predicted yield per land area was obtained by multiplying TCA/ha × FCT × CY. The models' predictive ability was evaluated for 64 different plots in 2001 and 2002. Statistical analysis showed the models to be valid for the forecast of potential yields in apple, so that they represent a useful tool for early crop prediction and evaluation of losses due to late frosts.

scholarly journals A Method for Quantifying Whole-tree Pruning Severity in Mature Tall Spindle Apple Plantings

HortScience ◽  
2017 ◽  
Vol 52 (9) ◽  
pp. 1233-1240 ◽  
Author(s):  
James R. Schupp ◽  
H. Edwin Winzeler ◽  
Thomas M. Kon ◽  
Richard P. Marini ◽  
Tara A. Baugher ◽  
...  
Keyword(s):  
Leaf Area ◽  
Fruit Size ◽  
Titratable Acidity ◽  
Severity Index ◽  
Cross Sectional Area ◽  
Soluble Solids ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross ◽  
Whole Tree

Pruning is the cutting away of vegetation from plants for horticultural purposes. Pruning is known to reduce apple tree size, increase fruit size and quality, and decrease yield. Methods for studying the effects of varying degrees of severity of pruning on a whole-tree basis have used qualitative descriptions of treatments rather than repeatable whole-tree quantitative metrics. In this study, we introduce a pruning severity index calculated from the sum of the cross-sectional area of all branches on a tree at 2.5 cm from their union to the central leader divided by the cross-sectional area of its central leader at 30 cm from the graft union. This limb to trunk ratio (LTR) was then modified by successively removing the largest branches of ‘Buckeye Gala’ to achieve six severity levels ranging from LTR 0.5 to LTR 1.75, with lower values representing more extreme pruning with less whole-tree limb area relative to trunk area. Pruning treatments were applied for three consecutive years and tree growth and cropping responses were observed for the first 2 years. With increasing pruning severity the following characteristics increased after seasonal growth: number of renewal limbs, number of shoots, shoot length, number of shoot leaves, shoot leaf area, final fruit set, fruit size, yield of large fruit, crop value from large fruit, soluble solids, and titratable acidity. The following characteristics decreased: limb age, number of secondary limbs, number of spurs, number of spur leaves, spur leaf area, the ratio of spur leaf area to shoot leaf area, fruit count per tree, yield, yield efficiency, crop value from small fruit, overall crop value, and sugar:acid ratio. The LTR provides a measurable way to define and create different levels of pruning severity and achieve consistent outcomes. This allows a greater degree of accuracy and precision to dormant pruning of tall spindle apple trees. The use of the LTR to establish the level of pruning severity allows the orchard manager to set crop load potential through regulation of the canopy bearing surface. This metric is also a necessary step in the development of autonomous pruning systems.

scholarly journals Yield, PFD Interception, and Crop Load Relationships in `Royal Gala' Apples

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1010A-1010
Author(s):  
Victor Garcia de Cortazar ◽  
Gabino Reginato
Keyword(s):  
Central Zone ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Data Set ◽  
Crop Load ◽  
Average Fraction ◽  
High Production ◽  
Simple Equations ◽  
Tree Fruits

Three different parameters were tested to estimate yield in `Royal Gala' apples. These are: a) parameters related to crop load—fruits per tree, fruits per cm2 of branch cross-sectional area, and fruits per hectare; b) parameters related with PFD interception: average fraction of PFD intercepted, total PFD intercepted during the season; and c) combination of the parameters a) and b). The data set was composed of measurements of PFD interception once a month and of yield components on various commercial apple orchards of the variety `Royal Gala' in the central zone of Chile between 2003 and 2006. The orchards were managed for high production, but there were differences of plantation distance, age, and size between them. Also, inside the orchard there were differences between trees. For the trees studied, there were variations of a factor of 10 for crop load, branch cross-sectional area, and tree size estimated as fractional interception of PFD at the beginning of the season. In spite of the big differences between trees, simple equations were fitted between yield and load parameters with coefficients of determination >0.95. Research funded by FONDECYT-Chile grant 1930695.

scholarly journals Statistical Model Estimates Potential Yields in Pear Cultivars `Blanquilla' and `Conference' before Bloom

2003 ◽  
Vol 128 (4) ◽  
pp. 452-457 ◽  
Author(s):  
Carlos Miranda Jiménez ◽  
J. Bernardo Royo Díaz
Keyword(s):  
Frost Damage ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Land Area ◽  
Flower Buds ◽  
Potential Yield ◽  
Cross Sectional ◽  
Yield Efficiency ◽  
Crop Density ◽  
Flower Density

Spring frosts are usual in many of Spain's fruit-growing areas, so it is common to insure crops against frost damage. After a frost, crop loss must be evaluated, by comparing what crop is left with the amount that would have been obtained under normal conditions. Potential crop must be evaluated quickly through the use of measurements obtainable at the beginning of the tree's growth cycle. During 1996 and 1997 and in 95 commercial plots of `Blanquilla' and `Conference' pear (Pyrus communis L.), the following measurements were obtained: trunk cross-sectional area (TCA, cm2), space allocated per tree (ST, m2), trunk cross-sectional area per hectare (TCA/ha), flower density (FD, number of flower buds/cm2 TCA), flower density per land area (FA, number of flower buds/m2 land area), cluster set (CS, number of fruit clusters/number of flower clusters, %), crop density (CD, number of fruit/cm2 TCA), fruit clusters per trunk cross-sectional area (FCT, number of fruit clusters/cm2 TCA), fruit clusters per land area (FCA, number of fruit clusters/m2 land area), fruit number per cluster (FNC), average fruit weight (FW, g), average yield per fruit cluster (CY, g), yield efficiency (YE, fruit g·cm-2 TCA), and tree yield (Y, fruit kg/tree). CS and average CY were related to the rest of the variables through the use of multiple regression models. The models that provided the best fit were CS = TCA/ha - FA and CY = -FA - FCT. These models were significant, consistent, and appropriate for both years. Predicted yield per land area was obtained by multiplying FA × CS × CY. The models' predictive ability was evaluated for 46 different plots in 2001 and 2002. Statistical analysis showed the models to be valid for the forecast of orchards' potential yield efficiency, so that they represent a useful tool for early crop prediction and evaluation of losses due to late frosts.

scholarly journals Growth and productivity characteristics of Japanese plum cultivars

2017 ◽  
Vol 62 (2) ◽  
pp. 133-141
Author(s):  
Dragan Milatovic ◽  
Dejan Djurovic ◽  
Gordan Zec
Keyword(s):  
Fruit Set ◽  
Fruit Weight ◽  
Cross Sectional Area ◽  
High Yield ◽  
Tree Trunk ◽  
Sectional Area ◽  
Cross Sectional ◽  
Yield Efficiency ◽  
Japanese Plum

Growth and productivity characteristics including: initial and final fruit set, yield per tree, trunk cross-sectional area, yield efficiency and fruit weight were studied in ten cultivars of Japanese plums in the Belgrade area for the period of three years (2013-2015). Initial fruit set ranged from 5.6 to 44.4%, and the final fruit set from 2.6 to 23.36%. The high yield per tree (over 10 kg) was obtained in cultivars ?Obilnaja? and ?Morettini 355?, whereas the low yield (under 5 kg) was obtained in cultivars ?Strival?, ?Black Amber?, ?Early Angeleno? and ?Autumn Giant?. The lowest vigor was observed in the cultivar ?Golden Plum?, and the highest in the cultivar ?Strival?. The majority of cultivars had a very large fruit (over 50 g). The yield was strongly positively correlated with initial and final fruit set (r = 0.84**; r = 0.92**, respectively). Fruit weight was moderately negatively correlated with initial and final fruit set (r = -0.67*; r = -0.63*, respectively).

scholarly journals Tree and Fruit Growth of `Napoleon' Cherry in Response to Rootstock and Planting Method

HortScience ◽  
1990 ◽  
Vol 25 (2) ◽  
pp. 176-178 ◽  
Author(s):  
Anita N. Miller ◽  
Porter B. Lombard ◽  
Melvin N. Westwood ◽  
Robert L. Stebbins
Keyword(s):  
Fruit Weight ◽  
Cross Sectional Area ◽  
Fruit Growth ◽  
Sectional Area ◽  
Cumulative Yield ◽  
Cross Sectional ◽  
Yield Efficiency ◽  
Canopy Volume ◽  
Tree Holes ◽  
Planting Method

`Napoleon' grafted onto Colt, F/12-1, and MxM60 rootstock were planted into three types of tree holes: augered; backhoed, and backhoed plus fumigation. The auger treatment resulted in lower yields, smaller trunk cross-sectional area (TSCA), and smaller canopy volume when compared to backhoed holes. Fumigation had no significant effect. Trees on Colt rootstock were more precocious, had a smaller TCSA and canopy volume, greater cumulative yield efficiency, and, in 1987, the smallest fruit weight. The yield efficiency of Colt was the highest until 1988, when it was surpassed by MxM60, but was still similar to F/12-l. Yields were highest on trees of MxM60 in 1987 and 1988.

scholarly journals Early Performance of Four Apple Cultivars on Mark and M.26 Rootstocks

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 792F-793
Author(s):  
James R. Schupp
Keyword(s):  
Malus Domestica ◽  
Fruit Size ◽  
Cross Sectional Area ◽  
Planting Density ◽  
Sectional Area ◽  
Cross Sectional ◽  
Crop Load ◽  
Apple Cultivars ◽  
Early Performance ◽  
Plot Design

To evaluate the interactions between cultivar and rootstock, four apple (Malus domestica Borkh.) cultivars, `Pioneer Mac', `Marshall McIntosh', `Ginger Gold', and `Empire' on two rootstocks, M.26 and Mark, were planted in a split-plot design. After 5 years, `Pioneer Mac' and `Ginger Gold' had larger trunk cross-sectional area (TCSA) on M.26 than on Mark. `Marshall McIntosh' and `Empire' had larger TCSA on Mark than on M.26. Precocity, expressed as both number of flower clusters and yield, was greater for trees on Mark for all cultivars except `Ginger Gold', which had greater flower cluster numbers and yield on M.26. Fruit size was variable from year to year, depending on crop load; however, `Pioneer Mac' and `Ginger Gold' usually produced the largest fruit, while `Empire' consistently produced the smallest fruit—'Ginger Gold' appears to be incompatible on Mark. The results of this study demonstrate that cultivar × rootstock interactions can be significant and need to be considered when rootstock and planting density recommendations are made.

TRUNK GROWTH OF APPLE TREE AS AFFECTED BY CROP LOAD

1980 ◽  
Vol 60 (4) ◽  
pp. 1383-1391 ◽  
Author(s):  
D. H. WEBSTER ◽  
G. L. BROWN
Keyword(s):  
Linear Relationship ◽  
Linear Function ◽  
Apple Tree ◽  
Cross Sectional Area ◽  
Tree Size ◽  
Size Increase ◽  
Sectional Area ◽  
Apple Trees ◽  
Cross Sectional ◽  
Crop Load

Increase in mean trunk circumference (ΔC, cm) of 8- to 17-yr-old McIntosh/M.7 apple trees was a linear function of mean crop load (K, kg/cm2). A linear relationship between ΔC and K implies that, for a given initial tree size, increase in trunk cross-sectional area will be nearly linear with yield.

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