scholarly journals Applying Soybean Oil to Dormant Peach Trees Thins Flower Buds

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 615-619 ◽  
Author(s):  
Dennis E. Deyton ◽  
Renae E. Moran ◽  
Carl E. Sams ◽  
John C. Cummins
Keyword(s):  
Soybean Oil ◽  
Prunus Persica ◽  
Flower Buds ◽  
Flower Bud ◽  
Spring Frost ◽  
Fruit Maturity ◽  
Peach Trees

Applications of soybean oil to dormant peach [Prunus persica (L.) Batsch] trees were tested for prebloom thinning of flower buds in five separate experiments. Data were combined from experiments in which 2.5% to 20% emulsified soybean oil was sprayed on `Belle of Georgia' or `Redhaven' trees. The number of dead flower buds was concentration-dependent with maximum bud kill of 53% occurring with application of 12% soybean oil. The amount of thinning was fairly consistent from year to year, ranging from 34% to 51% when 10% soybean oil was applied, but was less consistent when 5% was applied, ranging from 6% to 40%. Overthinning by midwinter applications of soybean oil occurred in one experiment when bud mortality on nontreated trees was 40% due to natural causes. Mild to moderate spring freezes occurred in three experiments, but did not reduce yield more in soybean oil–thinned than in nontreated trees. Flower bud survival was improved when trees were sprayed with 10% or 12% soybean oil prior to a –4 °C spring frost. Applications of soybean oil to dormant trees thinned flower buds, reduced the amount of hand thinning required, and hastened fruit maturity.

scholarly journals Applying Soybean Oil to Dormant Peach Trees Alters Internal Atmosphere, Reduces Respiration, Delays Bloom, and Thins Flower Buds

1996 ◽  
Vol 121 (1) ◽  
pp. 96-100 ◽  
Author(s):  
R.E. Myers ◽  
D.E. Deyton ◽  
C.E Sams
Keyword(s):  
Soybean Oil ◽  
Prunus Persica ◽  
Feedback Inhibition ◽  
Total Concentration ◽  
Branch Length ◽  
Flower Buds ◽  
Flower Bud ◽  
Crude Soybean Oil ◽  
Degummed Soybean Oil ◽  
Peach Trees

Dormant `Georgia Belle' peach [Prunus persica (L.) Batsch.] trees were sprayed in early February 1992 with single applications of 0%, 2.5%, 5.0%, 10.0%, or 20.0% (v/v) crude soybean oil. `Redhaven' trees were sprayed in February 1993 with single applications of 0%, 2.5%, 5.0%, 10.0%, or15% degummed soybean oil. Additional treatments of two applications of 2.5% or 5.0% oil were included each year. Both crude and degummed soybean oil treatments interfered with escape of respiratory CO2 from shoots and increased internal CO2 concentrations in shoots for up to 8 days compared to untreated trees. Respiration rates, relative to controls, were decreased for 8 days following treatment, indicating a feedback inhibition of respiration by the elevated CO2. Thus, an internal controlled atmosphere condition was created. Ethylene evolution was elevated for 28 days after treatment. Flower bud development was delayed by treating trees with 5% crude or degummed soybean oil. Trees treated with 10% crude or degummed soybean oil bloomed 6 days later than untreated trees. Repeated sprays of one half concentration delayed bloom an additional four days in 1992, but < 1 day in 1993 compared to a single spray of the same total concentration. Application of soybean oil caused bud damage and reduced flower bud density (number of flower buds/cm branch length) at anthesis. In a trial comparing petroleum oil and degummed soybean oil, yields of trees treated with 6% or 9% soybean oil were 17% greater than the untreated trees and 29%more than petroleum treated trees. These results suggest that applying soybean oil delays date of peach bloom and may be used as a bloom thinner.

scholarly journals Ethephon Prolongs Dormancy and Enhances Supercooling in Peach Flower Buds

1991 ◽  
Vol 116 (3) ◽  
pp. 500-506 ◽  
Author(s):  
Edward F. Durner ◽  
Thomas J. Gianfagna
Keyword(s):  
Prunus Persica ◽  
Storage Period ◽  
Bud Dormancy ◽  
Late Winter ◽  
Flower Buds ◽  
Flower Bud ◽  
Ethephon Treatment ◽  
Bud Growth ◽  
Peach Trees ◽  
Heat Requirement

The heat requirement for flower bud growth of container-grown peach trees [Prunus persica (L.) Batsch. cvs. Redhaven and Springold] in the greenhouse varied inversely and linearly with the length of the cold-storage period (SC) provided to break bud dormancy. Ethephon reduced the rest-breaking effectiveness of the 5C treatment. Buds from ethephon-treated trees grew more slowly than buds from untreated trees upon exposure to 20 to 25C, resulting in later bloom dates. The effect of ethephon on flower bud hardiness in field-grown trees of `Jerseydawn' and `Jerseyglo' was studied using exotherm analysis after deacclimation treatments. Bud deacclimation varied with reacclimating temperature (7 or 21 C), cultivar, ethephon treatment, and sampling date. All buds were more susceptible to injury in March than in January or February. Buds reacclimated more rapidly at 21C than at 7C. `Jerseyglo' reacclimated more rapidly than `Jerseydawn'. Untreated buds were less hardy and also reacclimated more rapidly than treated buds. Ethephon enhanced flower bud hardiness in three distinct ways: 1) it decreased the mean low-temperature exotherm of pistils, 2) it increased the number of buds that supercooled after exposure to reacclimating temperatures, and 3) it decreased the rate of deacclimation, especially at 21C. Ethephon prolongs flower bud dormancy by increasing the chilling requirement. The rate at which flower buds become increasingly sensitive to moderate temperatures in late winter and spring is thus reduced by ethephon. Thus, ethephon delays deacclimation during winter and delays bloom in the spring. Chemical name used: (2-chloroethyl) phosphoric acid (ethephon).

scholarly journals Soybean Oil as a Prebloom Flower Bud Thinner for Peaches

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 600c-600
Author(s):  
Gregory L. Reighard ◽  
David R. Ouellette
Keyword(s):  
Soybean Oil ◽  
Fruit Size ◽  
Fruit Weight ◽  
Late Winter ◽  
Flower Buds ◽  
Flower Bud ◽  
Cold Temperatures ◽  
Fruit Maturity ◽  
Flower Phenology ◽  
Peach Orchard

Survival of peach flowers during spring or winter freezes and large fruit size at harvest are critical for profitable peach production in the Southeast. Delaying both bud swell in late winter and flower phenology in spring reduces the risk of flower bud death from cold temperatures. Preliminary research in Tennessee using soybean oil (SO) as a dormant oil spray in place of Superior oil showed SO delayed peach bloom, thinned flower buds, and increased fruit size. In 1997, a `Harvester' peach orchard in Monetta, S.C., and a `Redhaven' orchard near Clemson, S.C., were sprayed in early February with 0%, 6%, 8%, 10%, and 12% SO mixed with 1% (by volume) Latron B-1956. Number of dead flower buds and the flower bud stages for each SO treatment were recorded during the first pink to full bloom flowering period. Excess fruit were hand-thinned in late April. Fruit set, maturity date, weight, and yield/tree were taken. Bud death increased from 14% (control) to 17% to 20% at the 8%, 10%, and 12% SO rates for `Redhaven' and from 13% (control) to 21% at the 10% and 12% rates for `Harvester'. Phenology was delayed 3-4 days for `Redhaven' at 8%, 10%, and 12% SO, but no differences were noted in the `Harvester' trees. No differences in fruit maturity occurred. Fruit weight and yield/tree was higher for all `Harvester' SO treatments and the `Redhaven' 10% and 12% SO treatments. No shoot phytotoxicity was observed.

scholarly journals Interactions of Ethephon, Whitewashing, and Dormant Oil on Peach Pistil Growth, Hardiness, and Yield

HortScience ◽  
1992 ◽  
Vol 27 (2) ◽  
pp. 104-105 ◽  
Author(s):  
Edward F. Durner ◽  
Thomas J. Gianfagna
Keyword(s):  
Prunus Persica ◽  
Interactive Effects ◽  
Growth Time ◽  
Flower Buds ◽  
Flower Bud ◽  
Bud Development ◽  
Main Effect ◽  
Lower Temperature ◽  
Peach Trees ◽  
Main Effects

Six-year-old peach trees [Prunus persica (L.) Batsch] were sprayed with ethephon (100 mg·liter–1) in Oct. 1989, whitewashed in Jan. 1990, and sprayed with dormant oil on one or two dates in Mar. 1990 to study possible interactive effects on flower bud hardiness, pistil growth, time of bloom, and yield. Flower buds from ethephon-treated trees supercooled to a lower temperature [mean low temperature exotherm (MLTE) of –18.5C] than buds from nontreated trees (MLTE of –17.7C) in February; there was no main effect of whitewashing or any interaction with ethephon. No treatment effects on hardiness were detected in March. Ethephon-treated pistils were smaller than nontreated pistils, and pistils from buds on whitewashed trees were smaller than those on nonwhitewashed trees. No main effects or interactions of dormant oil on pistil size were detected. Ethephon and whitewashing delayed bud development during bloom, but prebloom oil application(s) had no effect. Buds from ethephon-treated and whitewashed trees were more tolerant of freezes during bloom than buds from oil-sprayed trees, and yield was enhanced by ethephon and whitewashing. Prebloom oil sprays reduced yield compared with controls. Chemical name used: 2-chloroethylphosphonic acid (ethephon).

Thinning Peaches with Dormant Applications of Soybean Oil

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 496d-496
Author(s):  
R.E. Moran ◽  
D.E. Deyton ◽  
C.E. Sams ◽  
J.C. Cummins ◽  
A.L. Lancaster
Keyword(s):  
Soybean Oil ◽  
Yield Loss ◽  
Flower Buds ◽  
Flower Bud ◽  
Fruit Maturity ◽  
Before And After

Dormant applications of 0% to 20% soybean oil were tested as a prebloom thinner of `Georgia Belle' and `Redhaven' peach flower buds. Five separate experiments were conducted with soybean oil applied in late Jan. or early Feb. 1992, 1993, 1995, and 1997. The number of living and dead flower buds was counted on five or 10 shoots per tree before and 1 month after application in Expts. 1, 2, 3, and 4. In Expt. 5, buds were counted on two to three shoots per tree before and after a freeze of –4 °C during petal fall. Soybean oil thinned flower buds in all five experiments. The amount of flower bud death was concentration dependent with maximum bud kill of 53% occurring with application of 12% oil. Thinning was fairly consistent from year to year, ranging from 34% to 51% when 10% oil was applied, but was less uniform when 5% oil was applied and ranged from 6% to 40%. Overthinning occurred in Expt. 3 by all oil concentrations tested. Bud death in untreated trees was 40% in this experiment indicating that no thinning was needed. Mild to moderate spring freezes occurred in Expts. 2, 4, and 5, but did not result in greater yield loss in thinned than untreated trees. Soybean oil at 10% and 12% resulted in greater flower bud survival of a freeze in Expt. 5. Dormant applications of soybean oil thinned flower buds, reduced the amount of hand thinning and hastened fruit maturity.

scholarly journals Changes in Polyamine Levels in Relationship to the Double-sigmoidal Growth Curve of Peaches

1998 ◽  
Vol 123 (6) ◽  
pp. 950-955 ◽  
Author(s):  
Mosbah M. Kushad
Keyword(s):  
Fruit Development ◽  
Prunus Persica ◽  
Fresh Mass ◽  
Biosynthetic Enzymes ◽  
Related Phenomenon ◽  
Full Bloom ◽  
Flower Buds ◽  
Flower Bud ◽  
Fruit Maturity ◽  
Seed Growth

Polyamines and the activities of their biosynthetic enzymes were evaluated during peach (Prunus persica L. `Biscoe') mesocarp (pulp) and seed growth starting at full bloom and until full fruit maturity at 14 weeks after full bloom (AFB). Mesocarp fresh mass exhibited a double-sigmoidal pattern characteristic of peaches. Seed fresh mass increased to a maximum of≈1 g at 4 weeks AFB then remained unchanged during the remaining weeks of sampling. Free putrescine, spermidine, and spermine levels were significantly higher in the flower bud, declined in the mesocarp tissue during the first 2 weeks AFB, then exhibited another increase between 2 and 6 weeks AFB. In contrast, conjugated spermidine and spermine levels were low in flower buds, then increased to their maximum level at 6 weeks AFB, then declined at full fruit development. Ornithine decarboxylase (ODC, EC 4.1.1.17) activity was high in flower buds (89.3 nmol·h-1·mg-1 protein) and in early stages of mesocarp development then declined to its lowest level (5.8 nmol·h-1·mg-1 protein) at full-fruit development. Arginine decarboxylase (ADC, 4.1.1.19) activity did not change during the first 6 weeks of mesocarp growth but declined later, reaching its lowest (1.95 nmol·h-1·mg-1 protein) at 14 weeks AFB. During the first 5 weeks AFB, ODC activity was 3.0- to 4.5-fold that of ADC activity; however, at full-fruit maturity (14 weeks AFB) the activities of both enzymes were similar. The slowdown in mesocarp growth during pit hardening between 6 and 9 weeks AFB did not change polyamines concentrations or their biosynthetic enzymes. Free spermidine and spermine levels declined during seed development; however, between 7 and 9 weeks AFB an increase in putrescine was observed. Similarly, conjugated putrescine increased substantially during seed growth reaching its highest level of 680 nmol·g-1 fresh mass at week 8 then declined at the later weeks, while conjugated spermidine and spermine peaked at week 10 to 1,169 and 2,148 nmol·g-1 fresh mass. ODC and ADC activities declined between 3 and 5 weeks AFB. However, a significant increase in ADC but not ODC activity in the seed tissue was observed during pit hardening between 6 and 10 weeks AFB. Based on the rapid increase in putrescine and ADC activity in the seed tissue, it appears that pit hardening may be a stress-related phenomenon. Data also suggest that polyamine levels in the mesocarp and seed tissue are independently regulated.

scholarly journals The Effect of Soil Volume on Young Peach Tree Growth and Water Use

1994 ◽  
Vol 119 (6) ◽  
pp. 1157-1162 ◽  
Author(s):  
A-M. Boland ◽  
P.D. Mitchell ◽  
I. Goodwin ◽  
P.H. Jerie
Keyword(s):  
Water Use ◽  
Prunus Persica ◽  
Leaf Size ◽  
Shoot Density ◽  
Tree Size ◽  
Flower Bud ◽  
Cross Sectional ◽  
Tree Water Use ◽  
Soil Volume ◽  
Peach Trees

An experiment designed to study the effects of different root volumes was installed in Fall 1991. `Golden Queen' peach trees [Prunus persica (L.) Batsch.] were planted into different isolated soil volumes (0.025, 0.06, 0.15, 0.4, and 1.0 m3), which were essentially individual drainage lysimeters. Trunk cross-sectional area (TCA) increased from 5.76 to 14.23 cm2 for the smallest and largest volumes, respectively, while leaf area was 4.56 and 21.32 m2 for the respective treatments. Leaf size was not affected by soil volume. Soil volume was positively related to the number of lateral shoots produced, lateral shoot density, and internode length. Total flower bud number and flower bud density were inversely related to soil volume. Fruit set was similar among treatments despite an almost 4-fold difference in tree size. Tree water use (liters·mm-1 pan evaporation) increased with soil volume; however, when adjusted for tree size (tree water use per TCA), there were no consistent differences between treatments for tree water use over the season. These results suggest that trees planted in the smaller soil volumes were more efficient reproductively per unit of tree size and would be easier to manage in an ultra-high-density planting.

scholarly journals 614 PB 290 FLOWER BUD POSITION DETERMINES BLOOM AND FRUIT CHARACTERISTICS IN `ROME BEAUTY' APPLE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 520b-520
Author(s):  
Randy R. Lee ◽  
John K. Fellman ◽  
Esmaeil Fallahi
Keyword(s):  
Fruit Quality ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Flower Buds ◽  
Flower Bud ◽  
Terminal Flower ◽  
Fruit Maturity ◽  
Lateral Bud ◽  
Bud Position ◽  
Lateral Flower

The influence of flower bud position on bloom, fruit quality, and fruit maturity was investigated on `Rome Beauty' apple (Malus domestica Borkh.). Limbs on trees containing spur terminal flower buds and lateral flower buds were tagged and the number of blossoms counted every three days until bloom ended. At harvest, fruit from each bud type were selected and seed number, fresh weight, fruit quality characteristics, and onset of ethylene production were measured. Spur terminal flower buds began blooming earlier, blossomed for a longer period of time, and produced more blossoms than lateral flower buds. Fruit from spur terminal flower buds had more seeds, were heavier, and contained more starch than lateral bud fruit. Lateral bud fruit had higher pressure values, due to smaller size, and higher soluble solids, due to consumption of starch reserves. Fruit color and titratable acidity were not significantly different regardless of bud position. Spur terminal fruit started producing ethylene eight days later than lateral bud fruit, indicating they were maturing less quickly. Cultivars such as `Fuji', `Gala', and `Braeburn' display similar growth and fruiting habits.

scholarly journals Influence of Blossom and Fruit Thinning on Peach Flower Bud Tolerance to an Early Spring Freeze

HortScience ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 146-148 ◽  
Author(s):  
Ross E. Byers ◽  
R.P. Marini
Keyword(s):  
Prunus Persica ◽  
Fruit Set ◽  
Unit Length ◽  
Early Spring ◽  
Late Winter ◽  
Flower Buds ◽  
Flower Bud ◽  
Cross Sectional ◽  
Fruit Thinning ◽  
Crop Density

Peach trees [Prunus persica (L.) BatSch.] blossom-thinned by hand were overthinned due to poor fruit set of the remaining flowers; however, their yield was equivalent to trees hand-thinned 38 or 68 days after full bloom (AFB). Blossom-thinned trees had three times the number of flower buds per unit length of shoot and had more than two times the percentage of live buds after a March freeze that had occurred at early bud swell the following spring. Blossom-thinned trees were more vigorous; their pruning weight increased 45%. For blossom-thinned trees, the number of flowers per square centimeter limb cross-sectional area (CSA) was two times that of hand-thinned trees and four times that of the control trees for the next season. Fruit set of blossom-thinned trees was increased four times. Flower buds on the bottom half of shoots on blossom-thinned trees were more cold tolerant than when hand-thinned 68 days AFB. Fruit set per square centimeter limb CSA was 400% greater the following year on blossom-thinned trees compared to controls. Removing strong upright shoots on scaffold limbs and at renewal points early in their development decreased dormant pruning time and weight and increased red pigmentation of fruit at the second picking. The number of flower buds per unit shoot length and percent live buds after the spring freeze were negatively related to crop density the previous season for trees that had been hand-thinned to varying crop densities at 48 days AFB. According to these results, blossom thinning and fruit thinning to moderate crop densities can influence the cold tolerance of peach flower buds in late winter.

scholarly journals Flower Bud Load Influences Blueberry Vegetative and Fruit Development

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 682e-682
Author(s):  
B.E. Maust ◽  
J.G. Williamson ◽  
R.L. Darnell
Keyword(s):  
Leaf Area ◽  
Fruit Development ◽  
Reproductive Development ◽  
Dry Weight ◽  
Highbush Blueberry ◽  
Fresh Weight ◽  
Flower Buds ◽  
Flower Bud ◽  
Fruit Maturity ◽  
Southern Highbush

A field experiment was conducted in Gainesville, Fla., with two southern highbush blueberry cultivars, `Misty' and `Sharpblue', to investigate the influence of varying flower bud load on the timing and extent of vegetative and reproductive development. Flower bud load was adjusted on three different canes on ten plants by removing none, one-third, or two-thirds of the flower buds. Vegetative budbreak, leaf area, fruit number, and fruit fresh weight and dry weight were measured. Vegetative budbreak was delayed with increasing flower bud load. Vegetative budbreak, leaf area, and leaf area: fruit ratio decreased with increasing flower bud load. Fruit maturity was delayed and average berry fresh weight and dry weight declined with decreasing leaf area:fruit ratio. Responses were similar for both cultivars although `Misty' was more adversely affected by high flower bud load and low leaf area: fruit ratio.

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