Foliar Application of Ethephon Decreases Apical Dominance in `Orchid' Petunia (Petunia × hybrida Vilm.-Andr.)

Ethephon was applied as a foliar spray to 36-day-old petunia seedlings to determine its effectiveness at reducing apical dominance by increasing lateral shoot development. Ethephon application at rates of 125, 250 and 500 mg·L–1 to whole shoots of Petunia × hybrida `Orchid' decreased apical dominance compared to the control. The average length of a lateral shoot increased 56% as ethephon application rates increased from 0 to 500 mg·L–1. In Expt. I, ethephon-treated plants had a greater number of laterals than control plants. The number of nodes produced before the first flower bud was initiated increased from 15 to 21 as rates of ethephon increased from 0 to 500 mg·L–1. Ethephon delayed anthesis up to 10 days when applied at 500 mg·L–1 and up to 8 days when applied at 250 mg·L–1. The number of visible flower buds increased in all ethephon-treated plants compared to the control. Ethephon at 250 mg·L–1, increased shoot and root dry mass 37.9% and 20.4%, respectively, compared to untreated controls. Roots appeared healthy in both experiments, but phytotoxicity (mild chlorosis) occurred in Expt. II on plants treated with 500 mg·L–1. The experiment was repeated twice with similar results.

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Mouse Ear Disorder on River Birch Caused by Nickel Deficiency

HortScience ◽

10.21273/hortsci.39.4.892a ◽

2004 ◽

Vol 39 (4) ◽

pp. 892A-892 ◽

Cited By ~ 1

Author(s):

John M. Ruter*

Keyword(s):

Foliar Application ◽

Nickel Sulfate ◽

Normal Growth ◽

Dry Mass ◽

Application Rates ◽

Native Soil ◽

Leaf Dry Mass ◽

Mouse Ear ◽

Foliar Concentrations ◽

Nickel Deficiency

Mouse ear (leaf curl, little leaf, squirrel ear) has been a problem for growers of container-grown river birch (Betula nigra L.) since the early 1990's. Mouse ear has been noticed in several southeastern States as well as Minnesota, Ohio, Oregon, and Wisconsin, making it a national problem. The disorder is easy to detect in nurseries as the plants appear stunted. The leaves are small, wrinkled, often darker green in color, commonly cupped, and have necrotic margins. New growth has shortened internodes which gives plants a witches-broom appearance. Plants growing in native soil rarely express the disorder. Several common micronutrients have been evaluated with no results. A trial was initiated in June, 2003 to determine if nickel deficiency was the cause of mouse-ear. Symptomatic river birch trees growing in a pine bark substrate in containers were treated with foliar applications of nickel sulfate and a substrate drench. Topdress applications of superphosphate (0-46-0) and Miloroganite, products known to contain nickel, were also applied. At 16 days after treatment (DAT), up to 5 cm of new growth occurred on plants sprayed with nickel sulfate and foliar concentrations of nickel in the new growth increased five fold compared to control plants. At 30 DAT, shoot length increased 60%, leaf area increased 83%, and leaf dry mass increased 81% for trees receiving a foliar application compared to non-treated control plants. Treating trees with a substrate drench alleviated symptoms, whereas treatment with superphosphate and Milorganite did not. Trees receiving a foliar or drench application had normal growth for the remainder of the growing season. Additional studies are underway to refine methods of application, rates, and sources of nickel suitable for use.

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Rooting and Lateral Shoot Elongation of Verbena Following Benzylaminopurine Application

HortScience ◽

10.21273/hortsci.26.4.391 ◽

1991 ◽

Vol 26 (4) ◽

pp. 391-392 ◽

Cited By ~ 3

Author(s):

Sven E. Svenson

Keyword(s):

Foliar Application ◽

Shoot Elongation ◽

Dry Mass ◽

Stem Cuttings ◽

Stock Plant ◽

Lateral Shoot ◽

Rooting Zone ◽

Nodal Roots ◽

Lateral Bud ◽

Rooting Response

Rooting and growth of Verbena cuttings (Verbena × hybrids Voss) were measured to determine response to foliar-applied benzylaminopurine (BA). There was no rooting response to BA application when visible nodal roots were present at the base of the cutting. There was no response to 30, 100, or 300 mg BA/liter applied to the foliage 48 or 96 hours after excision from the stock plant. Rooting-zone dry mass, total cutting dry mass, and number of roots were increased by 30 mg BA/liter applied immediately after excision when there were no visible nodal roots at the base of the cuttings. Foliar application of BA at 10 or 30 mg·liter-1 increased lateral bud elongation of subsequently rooted shoots by 20% and 49%, respectively. Application of BA during cutting propagation to enhance subsequent lateral bud elongation does not appear to inhibit rooting in Verbena stem cuttings. Chemical name used: 6-benzylaminopurine (BA).

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Use of Ethephon as a Controlled Abscission Agent on Paprika Pepper

HortScience ◽

10.21273/hortsci.32.2.251 ◽

1997 ◽

Vol 32 (2) ◽

pp. 251-255 ◽

Cited By ~ 3

Author(s):

Brian A. Kahn ◽

James E. Motes ◽

Niels O. Maness

Keyword(s):

Capsicum Annuum ◽

Phosphonic Acid ◽

Foliar Application ◽

Dry Mass ◽

Single Application ◽

Flower Buds ◽

Green Fruit ◽

Precise Timing ◽

Marketable Fruit ◽

Fruit Mass

Mechanical harvest of paprika pepper (Capsicum annuum L.) produces a mixture of marketable and unmarketable fruit. Our objective was to increase the percentage of marketable red fruit in a once-over harvest by using ethephon to remove late-developing flower buds, blooms, and green fruit. Three experiments were conducted on field-grown plants in southwestern Oklahoma. We tested ethephon solutions of 0, 1000, 2000, 3000, and 4000 μL·L-1 as a one-time foliar application on various dates in September and October. Total dry mass of harvested fruit decreased linearly as ethephon rate increased in all experiments. Marketable fruit, as a percentage of total harvested fruit mass, increased linearly with ethephon rate in two of three experiments. Ethephon decreased the percent of total harvested fruit mass due to green fruit in all experiments. We recommend a single application of ethephon at about 2000 to 3000 μL·L-1 as a controlled abscission agent to increase the percentage of harvested red fruit in paprika pepper. The precise timing of the application will vary with the situation, but the last 10 days in September seemed an appropriate interval for southwestern Oklahoma. Chemical name used: (2-chloroethyl)phosphonic acid (ethephon).

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(93) Vegetative and Flower Bud Development, and Fruit Set of Low-chill Peach Cultivars in North-central, Central, and Southwest Florida

HortScience ◽

10.21273/hortsci.41.4.1029a ◽

2006 ◽

Vol 41 (4) ◽

pp. 1029A-1029

Author(s):

Todd Wert ◽

Jeffrey G. Williamson ◽

Robert E. Rouse

Keyword(s):

Fruit Set ◽

Average Length ◽

Flower Buds ◽

Flower Bud ◽

North Central ◽

Bud Development ◽

Central Florida ◽

Southwest Florida ◽

Vegetative Buds ◽

Flower Bud Development

Four low-chill peach cultivars were evaluated at three locations in Florida for vegetative and reproductive bud development and fruit set. Twenty trees (five each of `Flordaprince', `Tropicbeauty', `UFgold', and `Flordaglo') were planted at each site in Feb. 2002. Prior to budbreak in Spring 2004 and 2005, three shoots per tree of average length and diameter were selected at a height between 1.5–2.0 m and the numbers of vegetative and flower buds per node were recorded for each shoot. No consistent pattern for the number of vegetative buds per node was observed among cultivars and locations, or across years. However, 'Tropicbeauty' tended to have fewer vegetative buds per node than `Flordaprince' during both seasons, although not at all locations. Overall, the number of flower buds per node was greater for north-central Florida than for central or southwest Florida. There were no consistent tends over years and among locations for the ranked order of flower buds per node by cultivar. The percentage of nodes without flower or vegetative buds (blind nodes) was generally greatest for `Tropicbeauty' at most locations during both years. During 2005, the percentage of blind nodes was greater in central and southwest Florida than in north-central Florida. Overall, fruit set was similar between the central and north-central Florida locations. Fruit set tended to be higher for `UFGold' and `Flordaglo' than for `Flordaprince' or `Tropicbeauty'.

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Bulking Duration and Daminozide Affect Growth and Flowering of Achillea ×‘Coronation Gold’

Journal of Environmental Horticulture ◽

10.24266/0738-2898-33.2.84 ◽

2015 ◽

Vol 33 (2) ◽

pp. 84-88

Author(s):

Mohan Li ◽

J. Raymond Kessler ◽

Gary J. Keever ◽

Wheeler G. Foshee

Keyword(s):

Plant Growth ◽

Foliar Spray ◽

Growth Retardant ◽

Main Stem ◽

Stem Length ◽

Flower Buds ◽

Flower Bud ◽

Open Flower ◽

Single Shoot

A study was conducted to determine the effects of bulking duration and the plant growth retardant daminozide on plant growth and flowering of greenhouse-grown ‘Coronation Gold’ yarrow (Achillea ×‘Coronation Gold’). Single-shoot liners of yarrow were transplanted on October 14 and December 2, 2010, into 15 cm (6 in) containers and bulked for 4, 6, 8, or 10 weeks prior to exposure to night-interrupted lighting (NIL). Increasing the bulking duration increased the number of shortened, thickened stems of rosette-like appearance, or offsets, that had developed from the base of the main stem by the end of bulking by 100 to 367% and reduced days to first and five open inflorescences, hereafter referred to as flowers, from the beginning of NIL by 13 to 16 days and 10 to 20 days for the October and December potting dates, respectively. Increasing the bulking duration increased flower and flower bud number by 67 and 25% in the October 14 and December 2 potting dates, respectively. Therefore, more flowers and flower buds formed on yarrow when potted early, compared to late potting. Lengths of the first five open flower stems were inconsistent and minimally affected by bulking duration. In a repeat of the experiment potted on December 2 using the same bulking treatments, 5,000 ppm of daminozide was applied as a foliar spray when half the plants in a bulking duration had begun to elongate and was reapplied 1 week later. Daminozide application decreased stem length at first open flower by 20 to 43%, but increased days to first flower and five open flowers by 6 and 8 days, respectively. As in the first experiment, increasing the bulking duration increased the number of offsets and flower and flower bud number and reduced days to first and five open flowers.

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

HortTechnology ◽

10.21273/horttech.26.1.30 ◽

2016 ◽

Vol 26 (1) ◽

pp. 30-35 ◽

Cited By ~ 1

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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PRECOCIOUS FLOWERING OF ARIZONA CYPRESS WITH GIBBERELLIN

Canadian Journal of Botany ◽

10.1139/b65-102 ◽

1965 ◽

Vol 43 (8) ◽

pp. 923-927 ◽

Cited By ~ 22

Author(s):

Richard P. Pharis ◽

Manfred D. E. Ruddat ◽

Cornell C. Phillips ◽

Erich Heftmann

Keyword(s):

Initial Treatment ◽

Foliar Application ◽

Growth Retardants ◽

Flower Buds ◽

Flower Bud ◽

Simultaneous Application ◽

Precocious Flowering ◽

Flower Bud Differentiation ◽

Cupressus Arizonica ◽

Amo 1618

Extremely early flowering (production of staminate strobili 88 days from germination) of Arizona cypress (Cupressus arizonica Greene) was obtained with foliar application of gibberellin A3 commencing at age 55 days. Trials with differing concentrations of gibberellin at various ages indicated that flower bud differentiation depends on both age and gibberellin concentration, younger seedlings requiring more exogenous gibberellin. Simultaneous application of two growth retardants (AMO-1618 and B-995) had no effect upon the number of flowers, but flower size was increased where B-995 and gibberellin were given together. The period of time between initial spraying and first visible appearance of staminate strobili is 23 to 25 days. On most plants 60 to 80% of the growing vegetative meristems are changed into flower buds within 60 days of the initial treatment, often resulting in over 500 flower buds on one plant. The pollen is viable.

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Prefinishing Strategies for Flowering Petunia × hybrida Vilm.

HortScience ◽

10.21273/hortsci.33.3.447b ◽

1998 ◽

Vol 33 (3) ◽

pp. 447b-447

Author(s):

Ryan M. Warner ◽

John E. Erwin

Keyword(s):

Petunia Hybrida ◽

Continuous Light ◽

Leaf Number ◽

Ambient Light ◽

Flower Bud ◽

Lateral Shoot ◽

Stage Of Development ◽

Shoot Number ◽

Before And After ◽

Plant Form

Petunia × hybrida Vilm. `Purple Wave' and `White Storm' were grown under different lighting treatments for different lengths of time at different stages of development during the first 4 weeks after germination. The objective of the experiment was to identify the effects of photoperiod and stage of development on date of anthesis and plant form at anthesis. Seedlings were transplanted from 25-cm3 “plugs” into 85-cm3 cell-packs prior to treatment initiation. Plants were grown under ambient photoperiod (April, St. Paul, Minn.) at 20 ± 1 °C before and after treatments. Lighting treatments were 4 weeks of either 9-h ambient light (SD), ambient light plus 100 μmol·m–2·s–1 continuous light (CT) provided by high-pressure sodium lamps, or varying combinations of weeks of SD and CT. After 4 weeks of treatment, plants either remained in cell-packs, were transplanted into 10-cm pots (one plant per pot), or 19-cm pots (three plants per pot), and grown until anthesis. Data collected included anthesis date, leaf number below the first flower, lateral shoot number, and flower bud number. A single week of CT was sufficient to induce flowering in `White Storm'. `Purple Wave' plants did not flower in response to lighting during the first 2 weeks of development. `Purple Wave' plants grown under CT during weeks 3 and 4 flowered with a lower leaf number than if grown in SD for all 4weeks. Consequences of these findings with respect to prefinishing seedlings and scheduling crops of different container sizes will be discussed.

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Morphological properties of fruit bearing shoots of apricot cultivars

Journal of Agricultural Sciences Belgrade ◽

10.2298/jas1403265m ◽

2014 ◽

Vol 59 (3) ◽

pp. 265-274 ◽

Cited By ~ 2

Author(s):

Dragan Milatovic ◽

Dejan Djurovic ◽

Gordan Zec

Keyword(s):

Average Length ◽

Great Variability ◽

The Other ◽

Morphological Properties ◽

Yield Potential ◽

Flower Buds ◽

Flower Bud ◽

Other Hand ◽

Vegetative Buds ◽

Coefficients Of Variation

Morphological properties of fruit bearing shoots: length, number of flower buds and vegetative buds and their ratio were studied in 20 apricot cultivars during a two-year period. Control cultivar for comparison was ?Hungarian Best? (?Magyar kajszi?), clone 235. Fruit bearing shoots of apricot were classified into three groups: shoots, sylleptic shoots and spurs. The average length of shoots ranged from 68.8 to 85.0 cm; of sylleptic shoots from 6.9 to 27.0 cm; and of spurs from 1.4 to 4.1 cm. Flower buds/vegetative buds ratio was higher in spurs and sylleptic shoots (2,5 on average), compared to shoots (1,8 on average). Most of the studied apricot cultivars are characterized by higher flower bud density compared to control cultivar (?Hungarian Best?), indicating their higher yield potential. For all studied traits statistically significant differences between cultivars were found. The great variability was found in length of shoots, number of flower buds, and number of vegetative buds, while small coefficients of variation were found in thickness of shoots and length of internodes. Based on the obtained results, recommendations for pruning can be made. Cultivars with a higher number of flower buds (per 1 m in length and in relation to vegetative buds) such as: ?Lenova?, ?Tomcot?, ?Veecot?, ?Ninfa?, ?Sophia?, ?Silvercot? and ?Goldrich? require severe pruning. On the other hand, cultivars with lower flower bud density e.g. ?Hungarian Best?, ?Cegledy Arany? and ?Bella d?Imola? can be pruned slightly.

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EFFECTS OF UNICONAZOLE MEDIA DRENCH AND FOLIAR SPRAY APPLICATIONS ON GROWTH OF PYRACANTHA, PHOTINIA, AND DWARF BURFORD HOLLY

HortScience ◽

10.21273/hortsci.25.9.1125c ◽

1990 ◽

Vol 25 (9) ◽

pp. 1125c-1125

Author(s):

Robert M. Frymire ◽

Janet C. Henderson

Keyword(s):

Chlorophyll Content ◽

Plant Species ◽

Foliar Application ◽

Foliar Spray ◽

Leaf Chlorophyll Content ◽

Leaf Chlorophyll ◽

Application Rates ◽

Ilex Cornuta ◽

Initial Results ◽

Pyracantha Coccinea

Uniform liners of pyracantha (Pyracantha coccinea Roem `Lalandei'), photinia (Photinia × fraseri Dress) and dwarf Burford holly (Ilex cornuta Lindl. and Paxt. `Burfordii Nana') were potted into 3.8 liter containers in a pine bark:sand medium. Ten weeks later, plants received uniconazole treatments as a media drench or foliar spray. The uniconazole drench rates were 0, 0.5, 1.0, and 3.0 mg ai per container for all three plant species. The foliar application rates were 0, 50, 100 and 150 ppm for pyracantha, 0, 25, 50 and 100 ppm for photinia, and 0, 10, 25, and 50 ppm for dwarf Burford belly. Plant heights and widths were recorded at 3 week intervals, and leaf chlorophyll content was determined by calorimeter at the same time as height and weight measurements. At harvest, leaf counts, leaf areas, and shoot, leaf and root dry weights were determined. Initial results indicate that both foliar and media drench treatments of uniconazole reduced growth of pyracantha and photinia at all rates. Only the two highest rates decreased growth of dwarf Burford holly when applied as either a media drench or a foliar spray.

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