scholarly journals Modifying Alternate Bearing of Spur-Type `Delicious' Apple with Ethephon

HortScience ◽  
2006 ◽  
Vol 41 (7) ◽  
pp. 1606-1611 ◽  
Author(s):  
Martin J. Bukovac ◽  
Paolo Sabbatini ◽  
Philip G. Schwallier
Keyword(s):  
Malus Domestica ◽  
Shoot Growth ◽  
Soluble Solids ◽  
Flower Initiation ◽  
Alternate Bearing ◽  
Full Bloom ◽  
Ethylene Concentration ◽  
Maturity Indices ◽  
The Mean ◽  
Harvest Maturity

The effect of ethephon on flowering and cropping of strongly alternate bearing spur-type `Delicious' apple (Malus domestica Borkh.) was evaluated in a 6-year study. Ethephon (200 mg·L–1), applied at 3, 3 + 6, and 3 + 6 + 9 weeks after full bloom in “on years,” increased flowering in “off years” by 33% and reduced flowering in “on years” by 17% compared with the control. The mean yield per tree for ethephon-treated trees over three “on years” and three “off years” was almost identical to that of the controls (82 vs. 80 kg/tree). However, the distribution of yield between “on” and “off” years was changed, 24% greater in “off years” and 10% less in “on years.” Ethephon reduced both the variation in yield, particularly in “off years,” and the magnitude of alternation. Ethephon had a direct effect on flower initiation because 1) it did not reduce shoot growth or yield in the “on years” (years of ethephon application) and 2) ethephon-treated trees initiated more flowers per kilogram of fruit produced than did the controls. The additional flowers initiated were functional because the amount of fruit produced per unit bloom density did not differ between control and ethephon-treated trees. Harvest maturity indices, namely internal ethylene concentration, firmness, starch index, soluble solids, and color, were not significantly affected, although internal ethylene concentration and starch index tended to be higher in fruit from treated trees.

scholarly journals Use of Maturity Indices for Predicting Poststorage Firmness of `Fuji' Apples

HortScience ◽  
1997 ◽  
Vol 32 (5) ◽  
pp. 909-910 ◽  
Author(s):  
Sylvia M. Blankenship ◽  
Michael Parker ◽  
C. Richard Unrath
Keyword(s):  
Harvest Date ◽  
Soluble Solids ◽  
Fruit Firmness ◽  
Apple Variety ◽  
Ethylene Concentration ◽  
Solids Concentration ◽  
Maturity Indices ◽  
Predicted Values ◽  
Harvest Maturity ◽  
Best Fit

`Fuji' apples (Malus domestica Borkh.) were harvested at three maturities for three consecutive seasons. Fruit firmness, soluble solids concentration, starch—iodine index (SI), and internal ethylene concentration were measured at harvest. Fruit were stored in 0 °C air storage for 8 months. Fruit firmness and other maturity indices were measured monthly during storage. Using a stepwise regression procedure, harvest maturity indices were used to predict firmness after air storage. When all maturity indices measured were represented in the model, R2 = 0.29, 0.34, and 0.26 at 4, 6, and 8 months, respectively. Use of only SI and fruit firmness in the model gave R2 values of 0.25, 0.29, and 0.24 for 4, 6, and 8 months, respectively. Although R2 values were low, they were highly significant. The model using fruit firmness and SI resulted in the best fit. Thus, an equation was developed using months of air storage, firmness, and SI at harvest. Actual firmness values correlated fairly well with predicted firmness values, usually within ≈5 N. On Washington apples, predicted values were 4.3 and 3.7 N too low compared to actual firmness values after 3 or 5 months' storage. In 1993, when predicted and actual firmness values were compared for Pennsylvania apples, predicted values ranged from 2.6 to 8.3 N too high after 3 months' storage, depending on harvest date. In 1994, Pennsylvania fruit stored 4 months had predicted values 0.5 N too high to 6.3 N too low, depending on harvest date. It may be possible to develop and refine models for an apple variety that would be applicable to several regions.

scholarly journals AN EVALUATION OF BENZYLADENINE AS A POSSIBLE CHEMICAL THINNER OF “EMPIRE”

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 592a-592
Author(s):  
V.E. Emongor ◽  
D.P. Murr ◽  
J.T.A Proctor ◽  
E.C. Lougheed
Keyword(s):  
Field Trials ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Research Station ◽  
Full Bloom ◽  
Ethylene Concentration ◽  
Solids Concentration ◽  
Cambridge Research ◽  
Thinning Effect ◽  
Soluble Solids Concentration

Field trials at Cambridge Research Station, Ontario, Canada, studied the thinning effect of benzyladenine (BA) on eighteen-year-old “Empire” apple trees. At 16 days after full bloom (fruit diameter 12.87 mm) whole trees were hand sprayed to drip point with BA (0, 100, or 200 mg.1-1). Untreated control trees were compared with treated and hand thinned trees. BA significantly reduced crop load on “Empire”. The thinning response to BA was linear, with recommended thinning occurring at 200 mg.1-1. At harvest, fruit weight, size (diameter and length), flesh firmness and soluble solids concentration, chlorophyll and anthocyanin contents, and seed number were increased by BA treatments. BA had no effect on fruit L:D ratio, internal ethylene concentration, maturity, and the onset of the respiratory climacteric, but significantly reduced respiration at harvest. BA also reduced ethylene production and ACC content at harvest, though the reduction was not significant. Although firmness of BA-treated fruit was significantly higher at harvest, upon storage for 1 month at 0-0.5°C and 90-95% RH the firmness advantage was lost BA shows potential as a thinner of “Empire” apple and has advantage of increasing fruit weight and size, since “Empire” is a relatively small apple compared to other commercial cultivars.

scholarly journals 444 Changes in Quality and Maturity of Late-season Peaches (cvs. O'Henry and Nos 21) during Maturation and Ripening

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 521A-521
Author(s):  
G.H. Reginato ◽  
L.E. Luchsinger
Keyword(s):  
Prunus Persica ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Fresh Weight ◽  
Flesh Color ◽  
Commercial Harvest ◽  
Maturity Indices ◽  
Harvest Maturity

Our objectives were to characterize the quality and maturity changes of peach [Prunus persica (L.) Batsch.] fruit cvs. O'Henry and Nos 21 during maturation and ripening and to identify harvest maturity indices by relating nondestructive and destructive variables. After fruit set, 400 fruit of similar diameter and tree position were tagged to follow maturation and ripening on the tree. During commercial harvest, 48 fruit were ramdomly harvested every 4 to 6 days. Ethylene evolution rate (EER) at 20 °C, fresh weight, and peel ground and cover color (L*, a*, b*, C* and Hue value) were measured to all 48 fruit. Flesh color, firmness at several fruit points, soluble solids (SS), pH, titratable acidity (TA), and SS/TA ratio were measured only to 24 fruit, and the rest were held for up to 7 days at 20 °C as a ripening period to measure the same characteristics previously mentioned. Pearson correlation coefficients were determined between variables to explore possible harvest maturity indices. The most significant changes occurred in EER and ground color (a* value) for both varieties and fresh weight only for cv. O'Henry. For `O'Henry' peaches the highest correlation (P < 0.001) was obtained between EER-suture firmness (r = -0.61). For cv. Nos 21 the highest correlation was between EER-shoulder firmness (r = -0.69). It was also found that fruit softening occurred mainly in the fruit shoulder for both cultivars. Therefore, no harvest maturity indices could be established for these cultivars.

scholarly journals Storage Responses of `Empire' Apples to Benzyladenine and Other Chemical Thinners

1994 ◽  
Vol 119 (2) ◽  
pp. 253-257 ◽  
Author(s):  
D.C. Elfving ◽  
E.C. Lougheed
Keyword(s):  
Malus Domestica ◽  
Soluble Solids ◽  
Starch Hydrolysis ◽  
Naphthaleneacetic Acid ◽  
Full Bloom ◽  
Ethylene Evolution ◽  
Flesh Firmness

In three trials over 3 years, foliar BA applications for fruitlet thinning of `Empire' apple (Malus domestica Borkh.) trees produced small and inconsistent effects on flesh firmness at harvest and after air storage. Soluble solids concentrations at harvest and after air storage were consistently increased by BA alone or together with GA4+7 [Promalin (PR)], and were also increased by CB in one trial. Starch hydrolysis was slightly delayed by BA applications in 1990. Ethylene evolution at harvest was increased by NAA in 1988 and slightly increased by PR applied 29 days after full bloom (DAFB) in 1990, while poststorage ethylene evolution was stimulated by BA and PR treatments in 1990 except BA at 29 DAFB. Incidence of poststorage disorders was low and largely uninfluenced by thinning treatments. Chemical names used: N-(phenylmethyl)-1H-purine-6-amine [benzyladenine (BA)]; BA plus gibberellins A4 and A7 (GA 4+7) [Promalin (PR)]; 1-naphthaleneacetic acid (NAA); 1-naphthalenyl methylcarbamate [carbaryl (CB)].

scholarly journals The Effect of BAS-125W on Apple Tree Growth, Fruit Quality, and Fireblight Suppression

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 557C-557 ◽  
Author(s):  
R.E. Byers ◽  
K.S. Yoder
Keyword(s):  
Shoot Growth ◽  
Erwinia Amylovora ◽  
Apple Tree ◽  
Fruit Weight ◽  
Soluble Solids ◽  
First Year ◽  
Full Bloom ◽  
Fruit Thinning ◽  
Shoot Weight ◽  
Fruit Diameter

In 1995, BAS-125W applied at 125 to 500 mg/liter 23 days after full bloom (AFB) to `Starkrimson Delicious'/MM 106 and MM111 reduced average shoot weight and length of the longest shoots in the top and scaffold limbs by 50% at the highest rate. The number of nodes on the lower 40 cm of each shoot was increased by 1.8 times by the growth retardant. The number of pruning cuts, pruning time, and pruning weight per tree was reduce by 30%, 20%, and 29%. Fruit diameter, color, soluble solids, starch, fruit weight, and fruit number per tree were not altered by BAS-125 W. Growth suppression appeared to be greater on trees with heavier crop loads. In 1996, BAS-125W applied at 250 mg/liter 8 days after full bloom was more effective than when applied 19 days AFB to `Starkrimson Delicious'/MM 106 and MM111. Multiple applications of two, three, and four sprays to the same trees at 3-week intervals further reduced shoot growth with each application. Four applications reduced shoot weight by 72%, shoot length by 60%, and basal shoot diameter by 25%, and the number of pruning cuts, pruning time, and pruning weight per tree was reduce by 75%, 55%, and 80%, respectively. Thinning activity of NAA, Sevin, or Accel was not affected by tank mixed sprays with BAS-125W when applied to Gala/M.27 trees 20 days AFB. Tank mixing BAS-125W with combinations of Vydate + Accel or Carbaryl + Accel + Oil did not alter fruit thinning of Fuji/M.27 (at 10 mm fruit diameter). In one experiment, BAS-125 may have potentiated thinning by ethephon and NAA 10 days AFB in another experiment. BAS-125 W sprays at petal fall + 1 and 2 weeks later significantly suppressed % infection by fireblight, Erwinia amylovora, in inoculated shoots. In addition, BAS-125W reduced canker length in the first-year growth in shoots inoculated 2 weeks after treatment.

scholarly journals Notching Techniques Increase Branching of Young Apple Trees

1994 ◽  
Vol 119 (4) ◽  
pp. 678-682 ◽  
Author(s):  
Duane W. Greene ◽  
Wesley R. Autio
Keyword(s):  
Malus Domestica ◽  
Shoot Growth ◽  
Secondary Xylem ◽  
Full Bloom ◽  
Apple Trees ◽  
Positive Linear Relationship ◽  
Effective Time ◽  
Lateral Shoots ◽  
Shoot Production ◽  
Bud Size

Apple trees (Malus domestica Borkh.) were notched with a hacksaw blade by removing a 2-mm-wide strip of bark from directly above a bud. The cut extended down to the secondary xylem and around about one-third of the circumference of the stem. The most effective time to notch was ≈2 to 4 weeks before full bloom. Notching was most effective at inducing shoot growth from buds on the top of a branch, less effective for buds on the side, and least effective for buds on the underside of a branch. On untreated controls, the most shoots grew from the upper one-third of 1- or 2-year-old growth, and very few shoots developed buds on the lower one-third. If a bud was notched, however, the pattern was similar and incidence of shoot development was high. The percentage of notched buds that developed into shoots was not influenced by wood age.There was a positive, linear relationship between bud size and the percentage of buds growing into lateral shoots and between bud size and the length of those lateral shoots. Over all years, experiments, and cultivars, notching increased shoot production ≈600%.

scholarly journals Growth Response of One-year-old `Granny Smith' Apple Branches in Relation to Time of Heading

HortScience ◽  
1992 ◽  
Vol 27 (7) ◽  
pp. 781-783 ◽  
Author(s):  
S.A. Oosthuyse ◽  
G. Jacobs ◽  
D.K. Strydom
Keyword(s):  
Malus Domestica ◽  
Growth Response ◽  
Shoot Growth ◽  
Heading Date ◽  
Late Summer ◽  
Late Winter ◽  
Full Bloom ◽  
Total Length ◽  
One Year

Upright l-year-old apple (Malus domestica Borkh. `Granny Smith') branches were headed at 14-day intervals (branches headed once each) during late winter and in spring [70 days before full-bloom (DBFB) until 28 days after full-bloom (DAFB)] and budbreak and new shoot growth quantified on the remaining branch section after cessation of these events. When heading was performed 70, 56, or 42 DBFB, four to five buds broke on average. When branches were headed subsequently, the average number of buds breaking increased progressively, then decreased with heading date, the maximum number breaking (13) on branches headed 14 DAFB. An average of 10 or 11 buds broke per branch section when heading was performed 28 DAFB. In late summer, the total length of new shoots per branch section for the branches headed before full bloom averaged 113 cm, whereas that on the branches headed at or after full-bloom averaged 76 cm.

scholarly journals Leaf Development, Dry Matter Accumulation, and Distribution within Branches of Alternate-bearing `Kerman' Pistachio Trees

1997 ◽  
Vol 122 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Muntubani D.S. Nzima ◽  
George C. Martin ◽  
Chic Nishijima
Keyword(s):  
Dry Matter ◽  
Shoot Growth ◽  
Leaf Growth ◽  
Dry Mass ◽  
Dry Matter Accumulation ◽  
Pistacia Vera ◽  
Alternate Bearing ◽  
Full Bloom ◽  
Delayed Effects ◽  
One Year

We investigated the development of leaf area (LA) and the distribution of dry matter within branches of 25-year-old, alternate-bearing `Kerman' pistachio (Pistacia vera L.) trees that were in their natural “on” (heavy) or “off” (light) bearing cycles to determine the immediate and delayed effects of fruiting on shoot growth. Compared to “off” trees, individual leaves of “on” trees were greater in number and expanded twice as fast during the first 30 days after full bloom (FB) (FB + 30). Mature, fully expanded leaves of “on” trees were smaller (124.1±3.26 cm2) than those from “off” tree (163.3±3.40 cm2), indicating delayed demands of fruiting on initial leaf growth. Total LA per current shoot was greater in “on” than “off” trees because shoots of “on” trees averaged eight leaves, compared with six for “off” trees. More inflorescence buds per shoot (seven vs. three buds) abscised from “on” than from “off” trees. About 60% of the young developing nuts had abscised by FB + 30 when they weighed <250 mg each and another 25% abscised between FB + 30 and FB + 60 when individual nuts weighed ≈400 mg. The average total dry mass (DM) of individual branches of “on” trees increased 1322% (5·9 to 83·9 g) compared to 598% (4·2 to 29·3 g) in “off” trees. Besides nuts, leaves accumulated the greatest amount of dry matter within individual branches followed in decreasing order by current wood, 1-year-old wood, and inflorescence buds. DMs of individual leaves of “on” trees averaged between 15% and 48% greater than leaves of “off” trees. “Off” trees invested 4.6 g of dry matter into individual 1-year-old wood and 2.1 g into current wood. “On” trees, however, invested 1.3 g of dry matter into 1-year-old wood and 4.3 g of dry matter into current wood. One-year-old wood was an important major source of carbohydrates for developing leaves, current wood, rachises, and nuts. The immediate demands of fruiting on individual components of a branch were measured as losses in DMs. Individual leaves, current wood, 1-year wood, and rachises lost 1.1%, 0.3%, 1.1%, and 1.0%, respectively, of the average total DMs of individual branches of “on” trees. This loss was equivalent to 5.7%, 5.9%, 26.7%, and 16.4%, respectively, of the seasonal average peak DMs of the respective individual components of the branch.

scholarly journals Fruit Characteristics of `York' Apples during Development and after Storage

HortScience ◽  
2000 ◽  
Vol 35 (1) ◽  
pp. 95-98 ◽  
Author(s):  
Morris Ingle ◽  
Mervyn C. D'Souza ◽  
E.C. Townsend
Keyword(s):  
Acid Concentration ◽  
Malic Acid ◽  
Soluble Solids ◽  
Fruit Characteristics ◽  
Full Bloom ◽  
Ethylene Concentration ◽  
Titratable Acid ◽  
Solids Concentration ◽  
And Storage ◽  
Soluble Solids Concentration

Firmness, soluble solids concentration (SSC), starch index (SI), internal ethylene concentration (IE), and titratable acid concentration (TA) of `York Imperial' apple (Malus ×domestica Borkh.) fruit changed linearly with harvest date between 152 and 173 days after full bloom (DAFB). Firmness was positively correlated with TA, SSC was correlated with SI, and SI was negatively correlated with TA. After 150 days of refrigerated-air (RA) storage, there was no relationship between DAFB at harvest and firmness or superficial scald, but the malic acid concentration declined linearly and storage decay increased linearly with DAFB. Firmness had declined to a plateau and was not correlated with any variable at harvest. Malic acid concentration after CA storage was correlated with DAFB, firmness, SSC, and SI; scald was correlated with firmness and SI; and decay was correlated with DAFB, firmness, SSC, and SI. During 150 days of controlled-atmosphere (CA) storage (2.5% O2, 1.0% CO2), firmness and TA decreased as a linear function of DAFB. Percentage of fruit with scald and scald rating changed quadratically with DAFB, and decay increased linearly with DAFB. After 150 days of CA, firmness was correlated with DAFB, SI, and IE at harvest; TA was correlated with DAFB, firmness, SSC, TA, and SI; scald was correlated with firmness and SI; and decay was correlated with DAFB, SSC, and scald index at harvest. During 250 days of CA storage, firmness, TA, scald, and decay changed linearly with DAFB in only 1 or 2 years out of 3. Formulas were created to predict firmness after CA within 10 to 12 N (2.0–2.5 lb-f) and TA to within 25%.

scholarly journals 172 Changes in Quality and Maturity of Early Season Nectarines (cvs. Aurelio and Early May) during Maturation and Ripening

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 471F-472
Author(s):  
L.E. Luchsinger ◽  
G.H. Reginato ◽  
P. Miranda
Keyword(s):  
Prunus Persica ◽  
Fruit Set ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Flesh Color ◽  
Commercial Harvest ◽  
Maturity Indices ◽  
Harvest Maturity

The objectives of this study were to characterize the quality and maturity changes of nectarine (Prunus persica var. Nectarina) fruit cvs. Aurelio and Early May during maturation and ripening and to identify harvest maturity indices. After fruit set, 250 fruit of similar diameter and tree position were tagged to follow maturation and ripening on the tree. During commercial harvest, 48 fruit were ramdomly harvested every 2 to 3 days. Ethylene evolution rate (EER) at 20 °C, fresh weight, and peel ground and cover color (L*, a*, b*, C* and Hue value) were measured on all 48 fruit. Flesh color, firmness at several fruit points, soluble solids (SS), pH, titratable acidity (TA) and SS: TA ratio were measured only to 24 fruit, and the rest were held for up to 7 days at 20 °C as a ripening period to measure the same parameters mentioned above. Pearson correlation coefficients were determined between variables to explore possible harvest maturity indices. The most significant changes occurred in EER, fruit firmness, and peel ground color (a* and hue value). For `Aurelio' nectarines the highest correlations (P < 0.001) were obtained between logEER-tip firmness (r = -0.69), tip firmness-a* ground color (r = -0.66) and, tip firmness-hue ground color (r = -0.67). No important correlations (r > 0.60) were found for `Early May' nectarines. It was also found that fruit softening varies according to the point of measurement in the fruit depending on the cultivar.

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