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 Production and Postharvest Characteristics of Rosa hybrida L. `Meijikatar' Grown in Pots under Carbon Dioxide Enrichment

1993 ◽  
Vol 118 (5) ◽  
pp. 613-617 ◽  
Author(s):  
David G. Clark ◽  
John W. Kelly ◽  
Nihal C. Rajapakse
Keyword(s):  
Carbon Dioxide ◽  
Root Growth ◽  
Chlorophyll Concentration ◽  
Early Spring ◽  
Rosa Hybrida ◽  
Late Winter ◽  
Carbon Dioxide Enrichment ◽  
Flower Buds ◽  
Flower Bud ◽  
Leaf Chlorosis

The effects of carbon dioxide enrichment on growth, photosynthesis, and postharvest characteristics of `Meijikatar' potted roses were determined. Plants were grown in 350, 700, or 1050 μl CO2/liter until they reached 50% flower bud coloration and then were placed into dark storage for 5 days at 4 or 16C. Plants grown in 700 or 1050 μl CO2/liter reached the harvest stage earlier and were taller at harvest than plants produced in 350 μl CO2/liter, but there were no differences in the number of flowers and flower buds per plant among CO2 treatments. Plants grown in early spring were taller and had more flowers and flower buds than plants grown in late winter. Shoot and root growth of plants grown in 700 or 1050 μl CO2/liter were higher than in plants produced in 350 μl CO2/liter, with plants grown in early spring showing greater increases than plants grown in late winter. Immediately after storage, plants grown in 350 μl CO2/liter and stored at 4C had the fewest etiolated shoots, while plants grown in 1050 μl CO2/liter and stored at 16C had the most. Five days after removal from storage, chlorophyll concentration of upper and lower leaves had been reduced by ≈50% from the day of harvest. Carbon dioxide enrichment had no effect on postharvest leaf chlorosis, but plants grown in early spring and stored at 16C had the most leaf chlorosis while plants grown in late winter and stored at 4C had the least leaf chlorosis.

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).

Effects of pollinators and flower bud herbivores on reproductive success of two ericaceous woody species differing in flowering season

2006 ◽  
Vol 84 (1) ◽  
pp. 112-119 ◽  
Author(s):  
Noriyuki Osada ◽  
Shinji Sugiura
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Woody Species ◽  
Early Spring ◽  
Relative Importance ◽  
Flower Buds ◽  
Flower Bud ◽  
Flowering Duration ◽  
Floral Longevity ◽  
Flowering Season

To investigate the relative importance of pollinators and flower bud herbivores on final fruit set, the ratios of flower to flower bud (flower/bud), fruit to flower (fruit/flower), and fruit to flower bud (fruit/bud) were examined for the two bumble-bee-pollinated ericaceous species that have different flowering seasons: Pieris japonica (Thunb.) D. Don produces flower buds in autumn and blooms in early spring, whereas Lyonia ovalifolia (Wall.) Drude produces flower buds and blooms in late spring. Floral longevity was longer in P. japonica than in L. ovalifolia, and bagged flowers had an even longer floral longevity. The fruit/flower ratio was similar between the cross-pollinated and control flowers in P. japonica, but was smaller in control flowers than in cross-pollinated flowers in L. ovalifolia. Despite unpredictable pollinator activity in early spring, long flowering duration and no competition for pollinators facilitated reproductive success of P. japonica. In contrast, short flowering duration and severe competition for pollinators limited the reproductive success of L. ovalifolia. Flower bud herbivory was more severe in P. japonica than in L. ovalifolia. In both species, predispersal seed herbivores were negligible. Consequently, the fruit/bud ratio was mainly affected by the flower/bud ratio in P. japonica and by the fruit/flower ratio in L. ovalifolia. Our results suggest that despite intense herbivory of flower buds, early spring flowering of P. japonica facilitates pollination because of less competition for pollinators in comparison to L. ovalifolia. Thus, the relative importance of pollinators and herbivores on fruit set differs between the two studied species that differ in flowering periods.

Dormancy in peach (Prunus persica) flower buds. V. Anatomy of bud development in relation to phenological stage

2002 ◽  
Vol 80 (6) ◽  
pp. 656-663 ◽  
Author(s):  
Herminda Reinoso ◽  
Virginia Luna ◽  
Richard P Pharis ◽  
Rubén Bottini
Keyword(s):  
Prunus Persica ◽  
Rapid Development ◽  
Late Winter ◽  
Phenological Stage ◽  
Plant Structure ◽  
Flower Buds ◽  
Flower Bud ◽  
Flower Opening ◽  
Flower Primordia ◽  
Floral Bud

Anatomical changes in the peach (Prunus persica (L.) Batsch.) flower buds were defined and then assessed and correlated with the phenological stage from early dormancy through to flower opening. The peach flower bud, unlike the vegetative bud, shows a continuous anatomical development during the late autumn and winter dormancy period, even though there are no obvious macroscopic changes. Sterile whorls differentiate rapidly in late summer through early autumn. In contrast, fertile whorls develop very slowly during winter; their rapid development begins in late winter and continues through early spring. The androecium develops throughout the winter, while the gynoecium develops in late winter. By late winter, the anthers begin to undergo microsporogenesis and microgametogenesis and the ovaries have formed ovules. Vascular connections between flower primordia and branch wood are complete by late winter, when rapid phenological changes begin. At this point in time, the peach floral bud enters a "rapid maturation phase" that ends in flower opening. Thus, for the peach flower bud at least, the concept of dormancy as "a temporary suspension of visible growth of any plant structure containing a meristem" that was proposed by earlier researchers appears inappropriate. Rather, cell division, enlargement, and differentiation, which lead to organogenesis, take place throughout the entire "dormancy" period.Key words: dormancy, floral bud anatomy, floral bud phenology, peach, Prunus persica.

scholarly journals Heading Fruiting Shoots before Bloom Is Equally Effective as Blossom Removal in Peach Crop Load Management

HortScience ◽  
2002 ◽  
Vol 37 (4) ◽  
pp. 642-646 ◽  
Author(s):  
Richard P. Marini
Keyword(s):  
Prunus Persica ◽  
Fruit Set ◽  
Fruit Size ◽  
Fruit Weight ◽  
Load Management ◽  
Full Bloom ◽  
Crop Load ◽  
Fruit Thinning ◽  
Crop Density ◽  
Net Profit

Three experiments were performed to determine if pruning treatments could reduce the need for peach [Prunus persica (L.) Batsch] fruit thinning without reducing average fruit weight. To determine if dormant shoot heading affected fruit size simply by reducing the number of flowers per tree, all 1-year-old shoots on `Cresthaven' trees were headed by 50% or blossoms were removed from the terminal half of each shoot. At 45 days after full bloom, all trees were hand-thinned to obtain predetermined crop densities. Average fruit weight was highest on trees with blossom removal, but crop value and net profit were highest for nontreated trees. To determine the influence of treatment severity on fruit weight, all shoots on `Cresthaven' trees were blossom-thinned or headed to remove blossoms on varying proportions of each shoot. Fruit set and the number of fruit removed during postbloom thinning decreased as the percentage of a shoot that was headed or blossom-thinned increased. Average fruit weight at harvest and crop value were higher for trees with blossom removal than for trees with headed shoots. Fruit weight and crop value were not affected by the percentage of the shoot treated. In the final experiment, all shoots on `Cresthaven' trees were headed by 50% or were not headed. Heading of shoots reduced fruit set, number of fruits removed at thinning, and thinning time per tree, but yield, crop density, and average fruit weight were not affected by heading. Profit was increased by shoot heading one of the 3 years. Results from this study indicate that heading peach shoots by 50% while dormant pruning can reduce thinning costs without reducing fruit size, but a similar level of labor-intensive blossom removal may reduce postbloom thinning costs and improve fruit size.

Pollen development in relation to phenological stages of inflorescence expansion in Amelanchier alnifolia (saskatoon), with a comparison with buds forced out of dormancy

1999 ◽  
Vol 77 (2) ◽  
pp. 262-268
Author(s):  
Michael J Sumner ◽  
William R Remphrey ◽  
Richard Martin
Keyword(s):  
Time Frame ◽  
Early Spring ◽  
Flower Buds ◽  
Flower Bud ◽  
Phenological Stages ◽  
Inflorescence Development ◽  
Amelanchier Alnifolia ◽  
Bud Development ◽  
Internal Development ◽  
Flower Bud Development

A relationship was developed between phenological stages of inflorescence expansion and the internal development of pollen within the anther of Amelanchier alnifolia Nutt. flowers. The major microscopic events associated with microsporogenesis and microgametogenesis were correlated with seven stages of external inflorescence development in both natural buds and those forced from dormancy in different concentrations of gibberellin at various times of the year. In fall and early spring, it was found that gibberellin at a concentration of 2.5 mg/L forced buds to produce inflorescences that most resembled those from natural field populations. However, it was not possible to force flower buds to develop all the way to anthesis. Flower bud development stopped when the pollen was at the binucleate stage. Despite this limitation, the ability to force buds increases the time frame for the study of many aspects of the reproductive biology of A. alnifolia.Key words: microsporogenesis, microgametogenesis, gibberellin, GA, flowering.

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 Hedgerow Orientation Affects Canopy Exposure, Flowering, and Fruiting of `Anjou' Pear Trees

HortScience ◽  
1993 ◽  
Vol 28 (10) ◽  
pp. 984-987 ◽  
Author(s):  
Habib Khemira ◽  
P.B. Lombard ◽  
David Sugar ◽  
Anita N. Azarenko
Keyword(s):  
Similar Pattern ◽  
Fruit Set ◽  
Light Exposure ◽  
Growing Season ◽  
Pyrus Communis ◽  
The Sun ◽  
Flower Bud ◽  
Crop Density ◽  
Pear Trees ◽  
Different Levels

Mature hedgerows of `Anjou' pear (Pyrus communis L.) trees, planted north(N)-south (S) or east (E)-west (W), were used to study the effect of hedgerow orientation on fruiting and canopy exposure. In 1990, flower bud density tended to be lower on the E-W rows, especially on their N sides. Fruit set (FS) was highest on the S side of E-W rows and lowest on the N side, while the E and W sides of the N-S rows were intermediate. Crop density (CD) had a similar pattern as FS, with more fruit on the S than on the N side of the E-W rows. CD was more evenly distributed between the sides on the N-S hedgerows. Differences in FS and CD between sides were related to different levels of sunlight interception. Light exposure was lowest on the N sides of the E-W rows and highest on the S sides throughout the growing season and especially toward the equinoxes. Increased exposure to the sun on the S and W sides late in the season led to more fruit with solar injury. Fruit from E–W rows were larger and less firm. Accumulated yields over 11 years showed a 21.4% increase in the N-S rows over those of the E-W rows.

scholarly journals Flower Bud Stage and Chill Hours Influence the Activity of GA3 Applied to Rabbiteye Blueberry

HortScience ◽  
1992 ◽  
Vol 27 (4) ◽  
pp. 316-318 ◽  
Author(s):  
D.S. NeSmith ◽  
Gerard Krewer
Keyword(s):  
Gibberellic Acid ◽  
Growth Regulator ◽  
Flower Development ◽  
Fruit Set ◽  
Developmental Stages ◽  
Single Application ◽  
Flower Buds ◽  
Flower Bud ◽  
Vaccinium Ashei

Individual flower clusters of `Tifblue' rabbiteye blueberry (Vaccinium ashei Reade) were treated with 300 ppm GA at several flower bud stages to determine the activity of the growth regulator in promoting fruit set. Applications were made one time only at a specified stage of flower development, or once followed by a second application. A single application of GA when flower buds had elongated but corollas had not expanded (stage 5) led to the largest increase in fruit set. Two applications of GA, 10 to 18 days apart, increased fruit set compared with a single application at flower developmental stages other than stage 5. Fruit set promoted by a single spray of GA imposed on fully expanded corollas (stage 6) decreased with increasing number of chill hours (350, 520, 760, or 1150). Chemical names used: gibberellic acid (GA).

scholarly journals Relationship between flowering, fruit setting and environmental factors on consecutive clusters in greenhouse tomato (Lycopersicon lycopersicum (L) Karsten)

2003 ◽  
Vol 9 (3-4) ◽  
Author(s):  
Z. Pék ◽  
L. Helyes
Keyword(s):  
Environmental Factors ◽  
Fruit Set ◽  
Early Spring ◽  
Temperate Zone ◽  
Late Winter ◽  
Greenhouse Tomato ◽  
Fruit Setting ◽  
Lycopersicon Lycopersicum

The main season of greenhouse tomato begins late winter or early spring in the northern Temperate Zone. During this period decisive environmental factors affect flowering and fruit setting. In the present experiments, progress and dynamics of greenhouse tomato flowering and fruit set were examined in 1999 and 2001 spring. The beginning and the end of flowering and fruit set, the number of flowers and fruits set in each cluster were recorded. Flowering and fruit set characteristics were analysed with respect to the accumulated PAR and temperature were calculated for each cluster. One flower required 31.3 mol M-2 of accumulated PAR and 38 °C of sum temperature as an average for anthesis. One fruit required 27.9 mol m-2 of accumulated PAR and 33.3 °C of sum temperature as an average for fruit setting.

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