067 SHOOT ORIENTATION AFFECTS PEACH SHOOT AND FRUIT GROWTH

One-year old fruiting shoots averaging 50 cm in length were tagged according to naturally-occurring orientations ranging from vertical to horizontal throughout the canopies of dormant `Encore' peach (Prunus persica L Batsch) trees. Following fruit set, tagged shoots were thinned to two or three fruit per shoot. Fruit diameter, terminal shoot extension, and shoot orientation were measured at intervals throughout the season. Fruit were harvested at uniform maturity based on ground color for assessment of fresh weight, diameter, percent red blush, and red color intensity. A linear relationship (p=.001) was found between final fruit size and initial orientation, with fruit diameters 6 percent larger on shoots initially oriented horizontally than those initially vertical. Fruit size differences were not detected until the last two to three weeks of growth. Fruit size response to orientation was found to be independent of light. Red color development was not influenced, probably due to fairly uniform light environments within the canopies. Terminal shoot length was linearly related to initial orientation, with shoots initially oriented horizontally having the least terminal shoot extension. Development of lateral shoot growth in relation to shoot orientation will be discussed.

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Nitrogen Fertilization, Midsummer Trunk Girdling, and AVG Treatments Affect Maturity and Quality of `Jonagold' Apples

HortScience ◽

10.21273/hortsci.39.3.493 ◽

2004 ◽

Vol 39 (3) ◽

pp. 493-500 ◽

Cited By ~ 13

Author(s):

James M. Wargo ◽

Ian A. Merwin ◽

Christopher B. Watkins

Keyword(s):

Fruit Size ◽

N Fertilization ◽

Growing Seasons ◽

Color Development ◽

Red Color ◽

Fruit Maturity ◽

N Status ◽

Red Coloration ◽

Leaf N

`Jonagold' apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] often fail to develop adequate red coloration at maturity and become soft and greasy in storage. During two growing seasons, we tested factorial combinations of three preharvest treatments affecting `Jonagold' quality at harvest and after storage: 1) three nitrogen (N) treatments [36 kg·ha-1 soil applied N, 6.9 kg·ha-1 of urea-N (1% w/v) in foliar sprays mid-May and June, or no N fertilizers]; 2) trunk girdling in early August each year; and 3) foliar applications of aminoethoxyvinylglycine (AVG, formulated as ReTain) 3 weeks before the first scheduled harvest. Fruit were sampled at four weekly intervals each year and evaluated for maturity and quality at harvest and after storage. Foliar urea and soil-applied N delayed red color development in 1998 but not 1999, increased fruit size in girdled and nonAVG treated trees in both years, and increased greasiness in 1999 only. AVG reduced fruit greasiness after storage both years. Nitrogen uptake was reduced in the dry Summer 1999, but N treatments still increased poststorage flesh breakdown. Mid-summer trunk girdling increased red coloration and intensity both years and improved market-grade packout. This effect was not caused by advanced maturity, although trunk girdling slightly increased skin greasiness. Girdling reduced fruit size only on trees of low N status. The AVG applications delayed maturity and red color development by 7 to 10 days in both years compared with untreated fruit. In 1998, the combination of AVG and N fertilization delayed red color development more than either treatment alone. Fruit softening and greasiness were reduced in AVG-treated fruit harvested at the same time as untreated fruit, but this effect was not observed when AVG treated fruit were harvested at comparable maturity 7 to 10 days later. Trunk girdling and withholding N fertilizer were the best treatments for enhancing red coloration, and foliar N concentrations of ≈2.0% (W/W) resulted in better packouts compared with higher leaf N levels. AVG was an effective tool for delaying fruit maturity and maintaining fruit quality awaiting harvest, but not for improving red coloration of `Jonagold' apples.

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Nonstructural Carbohydrates and Mesocarp Development as a Result of Blossom Thinning in Peach

HortScience ◽

10.21273/hortsci.30.4.770a ◽

1995 ◽

Vol 30 (4) ◽

pp. 770A-770

Author(s):

Janet S. Mrosek ◽

Stephen C. Myers

Keyword(s):

Cell Division ◽

Prunus Persica ◽

Histological Analysis ◽

Fruit Size ◽

Nonstructural Carbohydrates ◽

Full Bloom ◽

One Year ◽

Floral Bud ◽

The Relationship ◽

Control Samples

The relationship between cell division, nonstructural carbohydrates and fruit size was investigated using 5-year-old `Encore' peach [Prunus persica (L.) Batsch]. The trees, which were trained to two opposing scaffolds, were selected for uniformity based on tree size and floral bud density. One-year-old shoots ranging in size from 20 to 30 cm were tagged from throughout the canopy. At anthesis, one entire scaffold was thinned of 75% of its flowers, leaving 25% in the mid-section of each shoot. The opposing scaffold served as the control. Samples were taken at three intervals for histological analysis: Anthesis, 30 days, and 45 days after full bloom. Nonstructural carbohydrates were analyzed on samples taken at five intervals: Anthesis, 10, 20, 30, and 45 days after full bloom. Volumetric size increased 29% by 30 days after full bloom, and 64% by 45 days after full bloom. Final fruit size (volumetric) was increased 8% by harvest.

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Harvest Management of Marshall `McIntosh' Apples: Effects of AVG, NAA, Ethephon, and Summer Pruning on Preharvest Drop and Fruit Quality

HortScience ◽

10.21273/hortsci.38.6.1093 ◽

2003 ◽

Vol 38 (6) ◽

pp. 1093-1099 ◽

Cited By ~ 15

Author(s):

Ed Stover ◽

Michael J. Fargione ◽

Christopher B. Watkins ◽

Kevin A. Iungerman

Keyword(s):

New York ◽

New York State ◽

Fruit Size ◽

Late Summer ◽

Naphthalene Acetic Acid ◽

Harvest Management ◽

Hudson Valley ◽

Color Development ◽

Red Color ◽

Economic Considerations

`McIntosh' apples (Malus ×domestica Borkh.) display a rapid increase in ethylene production as they ripen, resulting in more preharvest drop and accelerated softening compared with other major cultivars. Economic considerations often dictate a choice between delaying harvest to achieve color development or harvesting earlier to avoid excessive fruit softening and drop. We have evaluated the effects of plant growth regulators (PGRs) and summer pruning on this balance. Treatments were applied to trees in the Mid-Hudson region in New York state in 1995 and 1996, and a subset of treatments was applied in the Champlain Valley region in 1996. NAA, applied at 10 mg·L-1 in 1995 and 20 mg·L-1 in 1996, reduced drop on only one sample date in only one of the three trials. Ethephon at 150 mg·L-1 plus 10 mg·L-1 NAA, accelerated ripening and permitted harvest before substantial drop occurred. However, earlier harvest resulted in smaller fruit size, and if ethephon-treated fruit were not picked within a narrow window, rapid drop ensued, and fruit developed a high senescent breakdown incidence during storage. ReTain, containing AVG, at 124 g·ha-1 a.i. delayed drop in all three trials, but its use resulted in firmer fruit after storage in only two of seven comparisons. Use of ethephon on AVG-treated trees enhanced red color but accelerated drop, although it was reduced less than when ethephon was used alone. Severe late summer pruning accelerated red color development, drop and ripening in both years of the study. AVG was more effective for management of `McIntosh' harvest in the cooler Champlain Valley region than in the Mid-Hudson Valley region. Chemical names used: naphthalene acetic acid (NAA); 2-chloroethylphosphonic acid (ethephon); aminoethoxyvinylglycine (AVG).

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Ethylene Inhibitors Delay Fruit Drop, Maturity, and Increase Fruit Size of 'Arlet' Apples

HortScience ◽

10.21273/hortsci.40.7.2061 ◽

2005 ◽

Vol 40 (7) ◽

pp. 2061-2065 ◽

Cited By ~ 11

Author(s):

Ross E. Byers ◽

D.H. Carbaugh ◽

L.D. Combs

Keyword(s):

Fruit Size ◽

Harvest Date ◽

Starch Degradation ◽

Fruit Firmness ◽

Ethylene Inhibitors ◽

Pull Force ◽

Color Development ◽

Fruit Drop ◽

Date Fruit ◽

Red Color

Aminoethoxyvinylglycine (AVG) applied as a spray to 'Arlet' apple trees inhibited fruit drop and increased the pull force necessary to detach the fruit. AVG delayed the loss of fruit firmness, starch degradation, fruit shriveling, and red color development. 1-Methylcyclopropene (1-MCP), applied as a gas or spray to trees in the field, did not affect fruit drop or pull force. The combination of AVG + 1-MCP (spray or gas) provided better control of fruit drop, slowed the loss of fruit firmness, starch degradation, and decrease in pull force than AVG alone. Thirty five days after the optimum harvest date, fruit firmness from trees sprayed with AVG + 1-MCP was maintained at 74.3 N. Fruit of the control was significantly lower at 61.4 N firmness. The delay in harvest caused untreated control fruit stems to turn brown and die, but stems on AVG treated trees remained green and fruit continued to grow. In the 35 days after the optimum harvest date, treated fruit increased 2.5 cm in fruit diameter. Chemicals used: Aminoethoxyvinylglycine (AVG), 1-Methylcyclopropene (1-MCP), and trisiloxane ethoxylate methyl ether (an organosilicone surfactant, Silwet L-77).

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Effects of AVG, NAA, Ethephon, and Summer Pruning on Preharvest Drop and Fruit Quality of `McIntosh'

HortScience ◽

10.21273/hortsci.33.3.513b ◽

1998 ◽

Vol 33 (3) ◽

pp. 513b-513 ◽

Cited By ~ 2

Author(s):

E.W. Stover ◽

C.B. Watkins ◽

M.J. Fargione ◽

K.A. Iungerman

Keyword(s):

Fruit Size ◽

Late Summer ◽

Naphthalene Acetic Acid ◽

Fruit Softening ◽

Fruit Firmness ◽

Color Development ◽

Red Color ◽

Accelerated Ripening ◽

Substantial Drop

Ethylene production increases dramatically during maturation and ripening of `McIntosh' apples, frequently resulting in preharvest drop and accelerated fruit softening. As harvest approaches, commercial growers must balance the need for color development with minimizing fruit softening and drop. The effects of plant growth regulators and summer pruning on this balance were evaluated in this study. Treatments were applied to trees in the Mid-Hudson in 1995 and 1996 and a subset of growth regulator treatments was applied in the Champlain Valley in 1996. NAA (naphthalene acetic acid) significantly reduced drop on only one sample date in only one of the three trials. Ethephon (2-chloroethylphosphonic acid) at 150 ppm plus 10 ppm NAA, accelerated ripening and permitted harvest before substantial drop occurred, but earlier harvest resulted in smaller fruit size. AVG (aminoethoxy vinyl glycine) at 124 gram a.i./ha, on otherwise untreated trees, significantly delayed drop compared to the controls in two of three trials and resulted in better fruit firmness out of storage. Use of ethephon on AVG-treated trees significantly enhanced red color but also accelerated drop, although drop was reduced compared to ethephon only treatment. Late summer pruning significantly accelerated red color development, drop and ripening in both years. Pruning 16 Aug. 1996 significantly accelerated drop compared to pruning 1 Aug. 1996. Combining AVG application and pruning on 16 Aug. 1996 resulted in improved color without increasing drop compared to controls.

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Preharvest Application of Methyl Jasmonate to 'Fuji' Apples Enhances Red Coloration and Affects Fruit Size, Splitting, and Bitter Pit Incidence

HortScience ◽

10.21273/hortsci.40.6.1760 ◽

2005 ◽

Vol 40 (6) ◽

pp. 1760-1762 ◽

Cited By ~ 35

Author(s):

David R. Rudell ◽

John K. Fellman ◽

James P. Mattheis

Keyword(s):

Methyl Jasmonate ◽

Fruit Size ◽

Early Season ◽

Late Season ◽

Initial Application ◽

Color Development ◽

Peel Color ◽

Acetate Methyl ◽

Red Color ◽

Bitter Pit

Repeated preharvest applications of methyl jasmonate (MJ) to 'Fuji' apple [Malus sylvestris var. domestica (Borkh.) Mansf.] fruit were evaluated for impacts on peel color, size, fruit finish, and maturation. MJ treatments at 2 week intervals began 48 days after full bloom (DAFB) (early season) or 119 DAFB (late season) and fruit were harvested 172 DAFB. MJ treatment stimulated significant increases in peel red color following the initial application and thereafter. Early season MJ treatment reduced fruit diameter and length to diameter ratio but slowed softening and starch hydrolysis. Fruit receiving late season MJ treatments had increased incidence of bitter pit and splitting, shorter green life, and slower softening. Results suggest preharvest application of MJ impacts apple color development and other aspects of fruit quality. Chemical name used: methyl 3-oxo-2-(2-pentenyl)cyclopentane-1-acetate (methyl jasmonate).

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Evaluation of New and Promising Apple Cultivars for New England

HortScience ◽

10.21273/hortsci.33.2.205d ◽

1998 ◽

Vol 33 (2) ◽

pp. 205d-205

Author(s):

Duane W. Greene

Keyword(s):

New England ◽

Fruit Size ◽

Fruit Characteristics ◽

Color Development ◽

Red Color ◽

Golden Delicious ◽

Apple Cultivars ◽

Horticultural Research ◽

Early Market ◽

Better Than

Over 225 apple cultivars grown at the Horticultural Research Center in Belchertown have been evaluated for fruit quality and fruit characteristics. Methods used to determine fruit characteristics and organoleptic assessment will be presented. The postharvest potential of the most promising apples will be presented. Two apples ripen about the first of September and show promise for early market. `Sansa' is a medium-sized red apple that ripens about the first of September. It is a high-quality apple with characteristics similar to `Gala'. `Ginger Gold' is a large, firm, mild-flavored, russet-free, yellow apple. `Honeycrisp' is a red apple that ripens in mid-September, before `McIntosh'. It is a large, mild-flavored apple that is sometimes erratic in red color development. It maintains firmness and explosive crispness out of storage better than any other apple evaluated. `Golden Supreme' is an extremely attractive, russet-free `Golden Delicious' type ripening 7 to 10 days before `Golden Delicious'. When ripe it has a very aromatic, fruity flavor. It stores better than `Golden Delicious'. Other apples with merit that have commercial potential include: `Hampshire', `Shizuka', `Cameo', `Creston', `Coop 25', `Coop 29', and `Braeburn'. `Pink Lady' is a very late maturing, new cultivar that is being heavily planted in other areas. Although it does mature here, based upon starch rating, fruit size is small, the flesh is dry and very tart, and taste is only fair.

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Improvement of `Fuji' Apple Color and Fruit Size using Reflective Materials

HortScience ◽

10.21273/hortsci.30.4.787b ◽

1995 ◽

Vol 30 (4) ◽

pp. 787B-787

Author(s):

Harry L. Andris ◽

Carlos Crisosto

Keyword(s):

Starch Content ◽

Fruit Size ◽

Soluble Solids ◽

Surface Color ◽

Climate Conditions ◽

Color Development ◽

Hot Climate ◽

Red Color ◽

Significant Difference ◽

Fuji Apple

Soil-applied reflective materials significantly improved the red color development, fruit size, and early harvestability of `Fuji' apple grown under hot climate conditions of the the San Joaquin Valley of California. Red surface color was significantly improved from 7.35% in the control to 14.27% where 60-inch-wide silver polypropylene o 48-inch-wide crinkled foil on cloth backing were applied to the soil between rows of `Fuji' apple grown on a Lincoln trellis. The weight per apple was also significantly increase where the reflective materials were used. There was no significant difference in soluble solids, acidity, pH, pounds firmness, or starch content. Packinghouse records showed a 33% increase in first harvest pack-out where the reflective materials were used. Total pack-out in the larger sizes was improved in the extra-fancy and US#1 grades, while the utility-grade fruit was reduced by using these materials. Ground color was shifted from green to yellow where the reflective materials were used.

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Hydrophobic Particle Films Improve Tree Fruit Productivity

HortScience ◽

10.21273/hortsci.33.3.548a ◽

1998 ◽

Vol 33 (3) ◽

pp. 548a-548 ◽

Cited By ~ 3

Author(s):

D.M. Glenn ◽

G. Puterka ◽

T. Baugher ◽

T. Unruh ◽

S. Drake

Keyword(s):

West Virginia ◽

Production Systems ◽

Fruit Size ◽

The United States ◽

Fruit Production ◽

Red Color ◽

Tree Fruit ◽

Fruit Productivity ◽

Leaf Level ◽

Hydrophobic Particle

Hydrophobic particle film technology (HPF) is a developing pest control system for tree fruit production systems. Studies were established in Chile, and Washington, Pennsylvania, and West Virginia in the United States, to evaluate the effect of HPF technology on tree fruit yield and quality. Studies in Chile, Washington, and West Virginia demonstrated increased photosynthetic rate at the leaf level. Yield was increased in peaches (Chile) and apples (West Virginia), and fruit size was increased in apples (Washington and Pennsylvania). Increased red color in apple was demonstrated at all sites with reduced russetting and `Stayman' cracking in Pennsylvania. HPF technology appears to be an effective tool in reducing water and heat stress in tree fruit resulting in increased fruit quality.

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Herbicide Effects on Weed Control and Shoot Growth of Young Apple (Malus sylvestris) and Peach (Prunus persica) Trees

Weed Technology ◽

10.1017/s0890037x00028785 ◽

1994 ◽

Vol 8 (4) ◽

pp. 840-848 ◽

Cited By ~ 2

Author(s):

Chester L. Foy ◽

Susan B. Harrison ◽

Harold L. Witt

Keyword(s):

Shoot Growth ◽

Field Experiments ◽

Prunus Persica ◽

Weed Species ◽

Apple Trees ◽

Herbicide Treatments ◽

One Year ◽

Broadleaf Species ◽

Old Trees ◽

Peach Trees

Field experiments were conducted at two locations in Virginia to evaluate the following herbicides: alachlor, diphenamid, diuron, metolachlor, napropamide, norflurazon, oryzalin, oxyfluorfen, paraquat, pendimethalin, and simazine. One experiment involved newly-transplanted apple trees; the others, three in apple and one in peach trees, involved one-year-old trees. Treatments were applied in the spring (mid-April to early-May). Control of annual weed species was excellent with several treatments. A broader spectrum of weeds was controlled in several instances when the preemergence herbicides were used in combinations. Perennial species, particularly broadleaf species and johnsongrass, were released when annual species were suppressed by the herbicides. A rye cover crop in nontreated plots suppressed the growth of weeds. New shoot growth of newly-transplanted apple trees was increased with 3 of 20 herbicide treatments and scion circumference was increased with 11 of 20 herbicide treatments compared to the nontreated control. Growth of one-year-old apple trees was not affected. Scion circumference of one-year-old peach trees was increased with 25 of 33 herbicide treatments.

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