scholarly journals Crop Load Affects Mineral Concentrations and Incidence of Bitter Pit in `Cox's Orange Pippin' Apple Fruit

1992 ◽  
Vol 117 (3) ◽  
pp. 373-376 ◽  
Author(s):  
I.B. Ferguson ◽  
C.B. Watkins
Keyword(s):  
Inverse Relationship ◽  
Fruit Size ◽  
Apple Fruit ◽  
Postharvest Storage ◽  
Crop Load ◽  
Fruit Maturity ◽  
Bitter Pit ◽  
Mineral Concentrations ◽  
Storage Disorders

Apple fruit (Malus domestics Borkh. cv. Cox's Orange Pippin) were harvested in four orchards from trees growing under the same conditions but differing in crop load. Regardless of fruit size, apples from light-cropping trees had lower Ca and higher K concentrations and more bitter pit than did fruit from trees with heavy crop loads. The inverse relationship between Ca concentration in the fruit and the incidence of bitter pit also varied according to crop load and could affect the ability to predict incidence of bitter pit from Ca measurements. Differences in fruit maturity that would influence bitter pit incidence were not associated with crop load. The enhanced susceptibility to storage disorders, such as bitter pit, in fruit of all sizes from light-cropping trees suggests the need to handle fruit from such trees differently for postharvest storage.

scholarly journals EFFECTS OF ROOTSTOCK ON `DELICIOUS' APPLE FRUIT PROPERTIES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1147a-1147
Author(s):  
Wesley R. Autio
Keyword(s):  
Mineral Composition ◽  
Fruit Size ◽  
Apple Fruit ◽  
Analysis Of Covariance ◽  
Crop Load ◽  
Fruit Maturity

The effects of rootstock on `Delicious' apple maturity, quality, size, mineral composition, and storability were studied over a 4-year period. Removing the effects of crop load and crop load within year by analysis of covariance produced results suggesting that M.27 EMLA and Ott.3 advanced fruit maturity and that M.7 EMLA delayed fruit maturity. M.9, MAC 9, OAR 1, M.9 EMLA, and M.26 EMLA either were inconsistent in their effect on maturity or consistently resulted in an intermediate maturity. Size, after adjusting for the effects of crop load and crop load within year, was consistently high for fruit from trees on M.9 EMLA, and lowest for fruit from trees on OAR 1. After adjusting for fruit size, fruit from trees on MAC 9 generally had high Ca contents, and fruit from trees on OAR 1 had low Ca contents. The effect of rootstock on storability appeared to be secondary and related to maturity and Ca level.

The effect of tree sprays of calcium, boron, zinc and naphthaleneacetic acid, alone and in all combinations, on the incidence of storage disorders in Merton apples

1976 ◽  
Vol 27 (3) ◽  
pp. 391 ◽  
Author(s):  
D Martin ◽  
TL Lewis ◽  
J Cerny ◽  
DA Ratkowsky
Keyword(s):  
Fruit Size ◽  
Calcium Nitrate ◽  
Mineral Elements ◽  
Zinc Nitrate ◽  
Naphthaleneacetic Acid ◽  
Mineral Element ◽  
Significant Treatment ◽  
Bitter Pit ◽  
One Year ◽  
Storage Disorders

The effect of four whole-tree sprays at monthly intervals on the fruit mineral element content and on the incidence of storage disorders in Merton apples was investigated for three years. Calcium nitrate, boric acid, zinc nitrate and naphthaleneacetic acid (NAA) were applied singly and in all possible combinations. There were no significant treatment interactions, which implied an absence of synergistic or antagonistic effects between spray components. Calcium nitrate was the only compound whose application consistently reduced the incidence of bitter pit and breakdown following cool storage for 4 months. In one year NAA reduced the incidence of these disorders, but it also reduced mean fruit size and increased the concentration of most of the mineral elements, including calcium, in the fruit at harvest. Zinc nitrate sprays had no effect. Boron application promoted the development of core flush in one year and of breakdown in two years, but did not affect the incidence of bitter pit. No relationship was observed between the levels of calcium and boron in the fruit.

The effect of irrigation and crop load on stem water potential and apple fruit size

1997 ◽  
Vol 72 (5) ◽  
pp. 765-771 ◽  
Author(s):  
A. Naor ◽  
I. Klein ◽  
I. Doron ◽  
Y. Gal ◽  
Z. Ben-David ◽  
...  
Keyword(s):  
Water Potential ◽  
Fruit Size ◽  
Apple Fruit ◽  
Stem Water Potential ◽  
Crop Load ◽  
Stem Water

scholarly journals Growth Response of Apple Fruit to NAA and Accel: Effect of Intraspur Competition and Position on a Spur

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 765D-765
Author(s):  
Brent L. Black ◽  
Martin J. Bukovac ◽  
Matej Stopar
Keyword(s):  
Growth Response ◽  
Fruit Size ◽  
Apple Fruit ◽  
Fruit Growth ◽  
Crop Load ◽  
Commercial Thinning ◽  
Whole Tree ◽  
Fruit Diameter

Apple fruit size is influenced by position on the spur, and location and number of competing fruits. King fruit appear to have the greatest potential to size and grow best in the absence of intraspur fruit competition (ISFC). Accel (A) and NAA (N), commercial thinning chemicals, influence fruit size beyond their effects on crop load. A 2-year study was conducted to determine the effect of ISFC and position (king, K, or lateral, L) on fruit growth in response to A and N. Branches from `Redchief Delicious' were thinned, after petal fall, to one K, one L, one K + one L, or two L fruits per spur. Whole-tree treatments of N (15 mg·liter–1), A (50 mg·liter–1, 1993; 25 mg·liter–1), and a combination (N+A) were applied at 10-mm king fruit diameter. A nontreated control was included. In 1993, N and N+A reduced fruit size only with ISFC, while A increased fruit size in the absence of ISFC. In 1994, A had no effect, but N and N+A reduced fruit growth with ISFC. In both seasons, A and N decreased the frequency of spurs bearing multiple fruit, while N+A dramatically increased number of spurs with multiple fruits (branch survey).

scholarly journals Responses of apple fruit size to tree water status and crop load

2008 ◽  
Vol 28 (8) ◽  
pp. 1255-1261 ◽  
Author(s):  
A. Naor ◽  
S. Naschitz ◽  
M. Peres ◽  
Y. Gal
Keyword(s):  
Water Status ◽  
Fruit Size ◽  
Apple Fruit ◽  
Crop Load

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 Emitter Placement and Calcium Plus Boron Solution Affect Elemental Content of Spur `Delicious' Apples

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 520D-520
Author(s):  
Richard C. Funt ◽  
M. Scott Biggs ◽  
Mark C. Schmittgen
Keyword(s):  
Soil Moisture ◽  
Environmental Conditions ◽  
Shoot Growth ◽  
Fruit Size ◽  
Apple Fruit ◽  
Tree Canopy ◽  
Elemental Content ◽  
Physiological Disorders ◽  
Soil Calcium ◽  
Bitter Pit

Physiological disorders of apples, such as cork spot and bitter pit, are a result of low soil calcium, low or excessive soil moisture, large fruit size, and environmental conditions. We report on the effect of microirrigation treatments on apple fruit when irrigation is applied as water alone or water plus a calcium (Ca)/boron (B) solution with applications applied over the tree canopy or under the tree canopy. Apples were harvested from trees in their 4th to 7th leaf and the number of fruit and size of fruit varied from year to year. In most years, there were no significant differences among treatments for fruit Ca. Fruit B was significantly higher in treatments where B was applied through the irrigation. Fruit N/Ca levels were lower when the fruit size was smaller, which was due to a higher number of fruit per tree. Year to year variations in fruit Ca levels also were likely to temperature, humidity, rainfall, fruit size, and shoot growth.

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 Rootstock Effects on Growth and Quality of `Gala' Apples

HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1231-1233 ◽  
Author(s):  
Yahya K. Al-Hinai ◽  
Teryl R. Roper
Keyword(s):  
Agricultural Research ◽  
Fruit Size ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Research Station ◽  
Final Size ◽  
Crop Load ◽  
Yield Efficiency ◽  
Load Effects

The effect of rootstock on apple size is not clear due to inconsistent results of published studies. This study was conducted over 3 years at the Peninsular Agricultural Research Station near Sturgeon Bay, WI on 6-year-old `Gala' apple trees (Malus domestica Borkh) grafted on Malling 26 (M.26), Ottawa 3, M.9 Pajam 1, and Vineland (V)-605 rootstocks. Fruit diameter was measured weekly. Fruit weight and volume were estimated by a quadratic regression of weekly measurements. Fruit weight was positively correlated with fruit volume. Rootstock had no effect on fruit growth and final size even with the removal of crop load effects. Crop load was a highly significant covariate for fruit size, but canopy light interception and seed count were not. Trees on M.26 EMLA had slightly higher yield in 2000 but rootstock did not affect yield efficiency any year. Rootstock had no influence on fruit quality attributes during 2001; however, in 2002, fruit obtained from trees on Pajam-1 tended to be less firm. Generally, apple fruit size was influenced by crop load and other factors, but not by rootstock.

Certain chemical thinning treatments advance maturity of Paulared apple

2001 ◽  
Vol 81 (3) ◽  
pp. 499-501 ◽  
Author(s):  
Charles G. Embree ◽  
Douglas S. Nichols ◽  
John M. DeLong ◽  
Robert K. Prange
Keyword(s):  
Adverse Effects ◽  
Key Words ◽  
Malus Domestica ◽  
Fruit Size ◽  
Fruit Colour ◽  
Apple Trees ◽  
Crop Load ◽  
Malus Domestica Borkh ◽  
Fruit Maturity ◽  
Napthaleneacetic Acid

Mature Paulared (Malus ×domestica Borkh L.)/MM106 apple trees with a heavy bloom were sprayed with carbaryl [Sevin® XLR 1.25 mL L–1 (600 mg L–1 a.i.)], benzyladenine (BA)/gibberellic acids (GA4 + 7) [Accel® 1.22 mL L–1 (23.1 mg L–1/2.31 mg L–1 a.i.)], carbaryl [Sevin® XLR 1.25 mL L–1 (600 mg L–1 a.i.)] + BA/GA4 + 7 [Accel® 1.22 mL L–1 (15.6 mg L–1/1.56 mg L–1 a.i.)] and napthaleneacetic acid (NAA) [FruitoneN® 0.32 g·L–1 (1.13 mg L–1 a.i.)] when fruitlet diameter was 7 mm. Ethephon [Ethrel® 2.29 mL L–1 (549.6 mg L–1 a.i.)] was applied at the 13.5 mm fruitlet diameter stage. Carbaryl alone, NAA and ethephon all resulted in improved fruit size at harvest, whereas BA/GA4 + 7 was ineffective as a thinner and did not alter fruit size at harvest. Of these treatments, only ethephon significantly reduced crop load. Both NAA and ethephon, and especially ethephon, advanced fruit maturity at harvest as indicated by a lower Streif index. Only ethephon increased commercial levels of fruit colour and following-year blossom density. Thus, while ethephon appears promising as a fruitlet thinner and a promoter of maturity for this cultivar, these effects will have to be balanced against possible adverse effects on storage and shelf life. Key words: Crop load, carbaryl, ethephon, apple maturity, Streif index

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