scholarly journals Peach Pistil Carbohydrate and Moisture Contents and Growth during Controlled Deacclimation following Ethephon Application

1991 ◽  
Vol 116 (3) ◽  
pp. 507-511 ◽  
Author(s):  
Edward F. Durner ◽  
Thomas J. Gianfagna
Keyword(s):  
Moisture Content ◽  
Phosphoric Acid ◽  
Prunus Persica ◽  
Carbohydrate Content ◽  
Flower Buds ◽  
Flower Bud ◽  
Moisture Contents ◽  
Ethephon Treatment ◽  
Bud Growth ◽  
Fall Application

Flower bud growth and carbohydrate content of pistils of two peach cultivars [Prunus persica (L.) Batsch. cvs. Jerseydawn and Jerseyglo] was studied during controlled postrest deacclimation in February and March at 7 and 21C following an application of ethephon (100 mg·liter-1, in October. Ethephon-treated pistils contained more sorbitol and sucrose than untreated pistils, and levels of both sugars decreased during deacclimation. Sorbitol content decreased more rapidly at 21C than at 7C in February, but no difference was detected in March. Fructose content increased during deacclimation in February and was not affected by cultivar, ethephon treatment, or deacclimation temperature. In March, fructose increased in untreated `Jerseydawn' pistils during deacclimation, but not in ethephontreated pistils. In `Jerseyglo', fructose was detected in all samples and declined during deacclimation. Glucose was not detected in treated pistils in February. In untreated pistils, glucose increased during deacclimation. In March, glucose was not detected in `Jerseydawn' pistils reacclimated at 7C. At 21C, glucose was detected only in untreated pistils after 2, 3, or 4 days of deacclimation. In `Jerseyglo', glucose was detected in all pistils. Moisture content of ethephon-treated pistils was lower than untreated pistils in both February and March. Pistil moisture content during deacclimation increased more slowly in ethephon-treated pistils than in untreated pistils in February, but not in March. Pistils sampled in March had a lower moisture content when reacclimated at 7C than at 21C. Pistil growth at 21C was slower in ethephon-treated buds than in untreated buds, but no difference was detected at 7C. The effects of a fall application of ethephon on the carbohydrate content of flower buds in relation to both winter deacclimation and growth in the spring are discussed. Chemical names used: (2-chloroethyl) phosphoric acid (ethephon).

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 ETHEPHON REDUCES PEACH FLOWER BUD REHARDENING

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1167e-1167
Author(s):  
Edward F. Durner ◽  
Thomas J. Gianfagna
Keyword(s):  
Low Temperature ◽  
Phosphoric Acid ◽  
Prunus Persica ◽  
Flower Bud ◽  
Ethephon Treatment ◽  
The Mean

Peach (Prunus persica (L.) Batsch cv Jerseydawn and Jerseyglo) flower bud hardiness was studied using exotherm analysis following application of ethephon ((2-chloroethyl) phosphoric acid, 0.7mM) in October. Rehardening varied with temperature (7 or 21C), cultivar, ethephon treatment, and sampling date. Buds were more susceptible to injury in March compared to January or February. Buds rehardened more rapidly at 21C than at 7C. `Jerseyglo' rehardened more rapidly than `Jerseydawn'. Untreated buds were less hardy and also rehardened more rapidly than treated buds. Ethephon enhanced flower bud hardiness by (1) decreasing the mean low temperature exotherm of pistils, (2) increasing the number of buds which supercooled after rehardening, and (3) it decreased the rate of rehardening.

scholarly journals Dormant Pruning and Fall Ethephon Application Influence Peach Pistil Hardiness

1995 ◽  
Vol 120 (5) ◽  
pp. 823-829 ◽  
Author(s):  
Edward F. Durner
Keyword(s):  
Significant Interaction ◽  
Prunus Persica ◽  
Heat Accumulation ◽  
Flower Buds ◽  
Flower Bud ◽  
Controlled Conditions ◽  
Main Effect ◽  
Ethephon Treatment

Flower bud hardiness of ethephon-treated (100 mg·liter-1 in October), dormant pruned (in December) `Redhaven' peach (Prunus persica L. Batsch.) trees was studied from December through March using exotherm analysis. In early December, buds not treated with ethephon were 0.5C hardier than ethephon-treated buds. From mid-December through March, ethephon-treated buds were 0.5 to 2.1C hardier than nontreated buds. When a main effect of pruning was detected, buds from pruned trees were 0.8 to 2.8C less hardy than buds from nonpruned trees. On several dates, a significant interaction on flower bud hardiness between ethephon treatment and pruning was detected. For trees not treated with ethephon, buds from pruned trees were 1.8 to 2.2C less hardy than those from nonpruned trees. Pruning did not affect hardiness of buds from ethephon-treated trees. Ethephon delayed bloom to the 75% fully open stage by 9 days. Pruning accelerated bloom to the 75% fully open stage by 3 days compared to nonpruned trees. Flower bud dehardening under controlled conditions was also studied. As field chilling accumulated, flower buds dehardened more rapidly and to a greater extent when exposed to heat. Pruning accelerated and intensified dehardening. Ethephon reduced the pruning effect. The percentage of buds supercooling from any ethephon or pruning treatment did not change as chilling accumulated. In trees not treated with ethepbon, fewer buds supercooled as heat accumulated, and pruning intensified this effect. In pruned, ethephon-treated trees, fewer buds supercooled after exposure to heat. The number of buds supercooling in nonpruned trees did not change with heat accumulation. Flower bud rehardening after controlled dehardening was also evaluated. After dehardening in early February, there was no difference in the bud hardiness of pruned or nonpruned trees. Buds from ethepbon-treated trees were hardier than those from nontreated trees. With reacclimation, buds from pruned trees were not as hardy as those from nonpruned trees. The percentage of buds supercooling from ethephon-treated trees did not change with deacclimation or reacclimation treatments. After deacclimation in late February, buds from pruned trees were 2.2C less hardy than those from nonpruned trees. After reacclimation, buds from pruned, ethephon-treated trees rehardened 2.6C while buds from all other treatments remained at deacclimated hardiness levels or continued to deharden. Ethephon-treated pistils were shorter than nontreated pistils. Pistils from pruned trees were longer than those from nonpruned trees. Deacclimated pistils were longer than nondeacclimated pistils. Differences in hardiness among ethephon and pruning treatments were observed, but there was no relationship between pistil moisture and hardiness.

scholarly journals Genotype, Temperature, and Fall-applied Ethephon Affect Plum Flower Bud Development and Ovule Longevity

1992 ◽  
Vol 117 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Yerko M. Morenol ◽  
Anita Nina Miller-Azarenko ◽  
William Potts
Keyword(s):  
Mineral Content ◽  
Boron Content ◽  
Dry Weight ◽  
Full Bloom ◽  
Flower Buds ◽  
Flower Bud ◽  
Terminal Flower ◽  
Ethephon Treatment ◽  
Bud Growth ◽  
Growth Chambers

Flower bud growth and ovule longevity of plum (Prunus domestics L.) cultivars Italian and Brooks and the effects of fall-applied ethephon and of temperature were studied. Fresh and dry weights of terminal flower buds were measured at l-week intervals from 50 days to 1 day before bloom in 1988. Buds were also analyzed for N, P, K, Ca, and B. After bloom, ovule longevity was determined using a fluorescence method after staining with aniline blue. Ovule longevity was determined in 1990 using shoots excised at full bloom from untreated and ethephon-treated trees of both cultivars and held in growth chambers for 18 days at 5, 10, 15, or 20C. `Brooks' flower buds showed a higher accumulation of fresh and dry weight than `Italian', and ethephon reduced bud weights in both cultivars. Ethephon did not affect mineral content of flower buds of `Brooks', but `Italian' flower buds contained a higher concentration of Ca and a lower concentration of P when treated with ethephon. Boron content was higher in the ethephon-treated buds of `Italian' trees on some sampling dates. Ovule longevity was higher for `Brooks' than for `Italian' in both years. Ethephon treatment delayed ovule senescence in `Italian' flowers, but had little or no effect on `Brooks' flowers. Increasing temperatures induced faster ovule senescence in both cultivars. Chemical name used. 2-chloroethylphosphonic acid (ethephon).

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.

Leaf absorption, withdrawal and remobilization of autumn-applied urea-N in apple

2004 ◽  
Vol 84 (1) ◽  
pp. 259-264 ◽  
Author(s):  
S. Guak ◽  
D. Neilsen ◽  
P. Millard ◽  
N. E. Looney
Keyword(s):  
Malus Domestica ◽  
Low Temperatures ◽  
Fruit Set ◽  
Urea Solution ◽  
Flower Buds ◽  
Flower Bud ◽  
Flower Opening ◽  
Total N ◽  
Bud Growth ◽  
Flower Quality

Six-year-old well-nourished Jonagold/M9 apple (Malus domestica) trees were sprayed 7 d after harvest with a 2% urea solution enriched with 9.9% atom 15N. Through 3 d of the absorption period, leaves absorbed 19.2% of the intercepted urea 15N. This low absorption could be in part due to unfavourable conditions, i.e., low temperatures (daily mean ≈5°C) and windy conditions following treatment. During leaf senescence, 48% of the urea 15N absorbed was withdrawn from leaves and most of that (95%) remained in the treated branch section. Of this portion, 65% of the urea 15N was found in dormant bark, 29% in wood, and 6% in flower buds. In the following spring, 46% of the stored urea 15N was remobilized for growth of the flower buds when sampled at the “pink” stage of bud development. This accounted for 3.8% of total N in these tissues. This contribution did not influence flower quality, estimated by the length of the period between flower opening and petal fall and the level of fruit set. Key words: Malus × domestica, urea-15N, flower bud growth, fruit set

scholarly journals Winter 2011 Low-temperature Injury to Stone Fruit Flower Buds in New Mexico

2011 ◽  
Vol 21 (6) ◽  
pp. 767-772 ◽  
Author(s):  
Shengrui Yao
Keyword(s):  
New Mexico ◽  
Prunus Persica ◽  
Prunus Avium ◽  
Agricultural Science ◽  
Tart Cherry ◽  
Science Center ◽  
Flower Buds ◽  
Flower Bud ◽  
Flower Primordia ◽  
Japanese Plum

Twelve peach (Prunus persica) cultivars, six apricot (Prunus armeniaca) cultivars, two japanese plum (Prunus salicina) cultivars, three european plum (Prunus domestica) cultivars, four sweet cherry (Prunus avium) cultivars, and three tart cherry (Prunus cerasus) cultivars were monitored for winter damage at New Mexico State University's Sustainable Agriculture Science Center in Alcalde, NM (main site), and the Agricultural Science Center in Los Lunas, NM (minor site), in 2011. Uncharacteristically low temperatures on 1 Jan. and 3 Feb. were recorded as −7.2 and −11.3 °F, respectively, at Alcalde, and 4.8 and −13.9 °F, respectively, at Los Lunas. On 10 Jan. at Alcalde, live peach flower bud percentage varied by cultivar, ranging from 11% for Blazingstar to 25% for PF-1, and 85% to 87% for Encore and China Pearl. Apricot flower buds were hardier, with 70% survival for ‘Perfection’, 97% for ‘Sunglo’, and 99% for ‘Harglow’ on 10 Jan. By 10 Feb., almost all peach flower primordia were discolored, with no cultivar showing more than 1% survival. Based on this information, the 10% kill of flower buds for most peach cultivars occurred at temperatures equal to or slightly higher than −7.2 °F, and 90% kill occurred between −7.2 and −11.3 °F. On 10 Feb., 0% to 15% of apricot flower buds on spurs or shoots of the middle and lower canopy had survived. For vigorous shoots in the upper canopy, apricot flower buds on 1-year-old shoots had a higher blooming rate than those on spurs of 2-year-old or older wood. Flower buds of japanese plum were also severely damaged with less than 0.2% survival for ‘Santa Rosa’ and 4.8% for ‘Methley’, but european plum were relatively unaffected with over 98% flower bud survival for ‘Castleton’ and ‘NY6’, and 87% for ‘Stanley’ after −11.3 °F at Alcalde. Cherry—especially tart cherry—survived better than peach, apricot, and japanese plum after all winter freezes in 2011.

scholarly journals Infection Efficiency of Venturia inaequalis Ascospores as Affected by Apple Flower Bud Developmental Stage

Plant Disease ◽  
1997 ◽  
Vol 81 (6) ◽  
pp. 661-663 ◽  
Author(s):  
S. Sanogo ◽  
D. E. Aylor
Keyword(s):  
Developmental Stage ◽  
Venturia Inaequalis ◽  
Growth Stages ◽  
Vegetative Shoot ◽  
Flower Buds ◽  
Flower Bud ◽  
Infection Efficiency ◽  
Tight Cluster ◽  
Bud Growth

The average infection efficiency of ascospores of Venturia inaequalis deposited on cluster leaves of apple flower buds was 6 to 16%, 3 to 9%, and 0.4 to 0.6% at tight cluster, first pink, and full pink-to-bloom, respectively. No lesions were observed on flower bud cluster leaves at petal fall. However, the leaves on the vegetative shoot emerging from the flower bud were highly susceptible; the average infection efficiency of ascospores on these leaves was 6 to 21%. The infection efficiency was more variable on young cluster and vegetative shoot leaves than on developing and mature cluster leaves. Results from this study indicate that differences in infection efficiency of V. inaequalis ascospores could be identified by apple bud growth stages.

scholarly journals Rootstock-induced Differences in Flower Bud Phenology in Peach

1992 ◽  
Vol 117 (5) ◽  
pp. 690-697 ◽  
Author(s):  
Edward F. Durner ◽  
Joseph C. Goffreda
Keyword(s):  
Prunus Persica ◽  
Temperature Profiles ◽  
Flower Bud ◽  
Spring Temperature ◽  
Bud Development ◽  
Bud Phenology ◽  
Bud Growth ◽  
Spring Frosts ◽  
Enhanced Yield ◽  
Scion Cultivar

Three peach [Prunus persica (L.) Batsch] rootstock plantings were monitored for date and rate of bloom during Spring 1989 and 1990 to determine if the time of scion bloom on different rootstocks is determined by the date of initiation of bud growth in the spring or by the duration of a particular bud stage. Included were a 1984 planting of `Redhaven' on eight rootstocks, a 1984 planting of `Rio-Oso-Gem' and `Loring', each on 11 rootstocks, and a 1986 planting of `Encore' on 18 rootstocks. The effect of rootstock on bud phenology was consistent within scion cultivar over two extremely different spring temperature profiles. In `Redhaven' and `Rio-Oso-Gem', rootstocks affected the dates but not the rates of bud development. Rootstocks affected both the dates and rates of `Loring' and `Encore' bud development. No consistent effect of rootstock on yield could be associated with delayed bud development in `Rio-Oso-Gem', `Redhaven', or `Loring'; however, delayed bud development of `Encore' on `Okinawa' x `Cardinal' and 62325 resulted in enhanced yield following spring frosts.

scholarly journals Efficient Breeder Seed Production Utilizing Ethephon to Promote Floral and Fruit Abscission in Ornamental Chile Peppers

2016 ◽  
Vol 26 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Derek W. Barchenger ◽  
Danise L. Coon ◽  
Paul W. Bosland
Keyword(s):  
Foliar Spray ◽  
Seed Number ◽  
Mature Fruit ◽  
Flower Buds ◽  
Flower Bud ◽  
Chile Pepper ◽  
Fruit Number ◽  
Breeder Seed ◽  
Ethephon Treatment ◽  
Chile Peppers

Controlled abscission of floral structures is an important horticultural technique that has many applications throughout the growing season. A novel use of chemical abscission in chile pepper (Capsicum annuum) is the removal of open flowers and fruit for the production of breeder seed. For efficiency of abscising flower buds, open flowers, and fruit of ornamental chile peppers, two foliar spray treatment levels, 1000 and 2000 ppm ethephon were tested. Ornamental chile peppers were chosen because they are prolific flower and fruit producers, making removal of potentially cross-pollinated fruit and open flowers laborious. Flower bud and flower number were reduced with both 1000- and 2000-ppm ethephon treatments, while fruit number decreased only with 2000-ppm ethephon treatment. ‘NuMex Easter’ was more sensitive to ethephon treatment as compared with ‘Chilly Chili’ and ‘Riot’. Ethephon had no negative impacts on end of the season growth index, mature fruit number, and seed number. We found ethephon can reduce numbers of flower buds, open flowers, and fruit with no long-term effect on mature fruit and seed number, making it a useful tool for the production of breeder seed in chile pepper breeding programs.

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