scholarly journals Application Timing of Daminizide and Flurprimidol after Shearing Affects Growth and Flowering of Coreopsis verticillata `Moonbeam'

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 603a-603
Author(s):  
J. Raymond Kessler ◽  
Gary J. Keever
Keyword(s):  
Growth Index ◽  
Plant Size ◽  
Height Growth ◽  
Shoot Length ◽  
Growth Retardants ◽  
Lateral Shoot ◽  
Shoot Height ◽  
Application Timing ◽  
Quality Rating ◽  
Response Surface Regression

Vegetative cuttings of Coreopsis verticillata `Moonbeam' were rooted under intermittent mist, pinched, and potted into 10-cm pots in a greenhouse. Plants were sheared to 6.5 cm above the pot rim 2 weeks after potting and given foliar sprays of daminozide at 0, 2550, 5100, or 7650 mg·L-1 or flurprimidol at 0, 50, 100, or 150 mg·L-1. Night-break lighting to provide long photoperiods was started the day of shearing. Growth retardants were applied at 0, 3, 6, 9, 12, or 15 days after shearing. Daminozide reduced shoot height, growth index, and lateral shoot length compared to the control by 69.3%, 69.2%, and 70.0%, respectively, while increasing quality rating by 67.3% and time to flower by 8 days at 5100 and 7650 mg·L-1. Response surface regression predicted that minimum plant size and maximum quality rating occurred when growth retardants were applied 5.7 to 8.3 days after shearing. Application timing had no effect on responses to flurprimidol. Shoot height, growth index, and lateral shoot length decreased quadratically with increasing rate while quality rating only improved compared to control. Flurprimidol did not cause a flowering delay.

scholarly journals Plant Growth Retardants Affect Growth and Flowering of Coreopsis verticillata ‘Moonbeam’

2007 ◽  
Vol 25 (4) ◽  
pp. 229-233
Author(s):  
J.R. Kessler ◽  
G.J. Keever
Keyword(s):  
Plant Growth ◽  
Maleic Hydrazide ◽  
Growth Index ◽  
Height Growth ◽  
Growth Retardant ◽  
Shoot Length ◽  
Lateral Shoot ◽  
Shoot Height ◽  
Quality Ratings ◽  
Quality Rating

Abstract This investigation was conducted to determine the plant growth retardant type, application method, and rate required to produce a marketable greenhouse pot plant of Coreopsis verticillata L. ‘Moonbeam’. Pruned plants in 10 cm (4 in) pots received growth retardant treatments in two experiments consisting of one application of ancymidol or paclobutrazol medium drenches at 0, 2, 4, or 6 ppm; daminozide spray at 0, 2550, 5100, or 7650 ppm; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 ppm; flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 ppm; or maleic hydrazide at 0, 360, 720, 1080, 1440, or 1800 ppm in the first experiment and sprays of daminozide at 0, 2550, 5100, or 7650 ppm; paclobutrazol at 0, 60, or 120 ppm; daminozide/paclobutrazol combinations at 0, 2550/16, 2550/32, 2550/48, or 2550/64 ppm, chloromequat at 0, 767, 1534, or 2301 ppm; or daminozide/chloromequat combinations at 0, 1275/1534, 2550/1534, 3825/1534, or 5100/1534 ppm in the second experiment. In the first experiment, there was a linear decrease in shoot height, growth index, and lateral shoot length with increasing rates of ancymidol and paclobutrazol drenches and flurprimidol sprays while daminozide decreased growth quadratically. There was a linear increase in shoot height and lateral shoot length with increasing rates of maleic hydrazide but no effect on growth index. Only daminozide and maleic hydrazide increased the number of days from treatment to flower with increasing rates. Quality ratings increased with increasing rates of ancymidol, daminozide, and flurprimidol with the highest ratings found at the two highest rates of daminozide and flurprimidol. Paclobutrazol spray did not affect the parameters measured. In the second experiment, chloromequat spray did not affect the parameters measured but when combined with increasing rates of daminozide, linearly decreased shoot height, growth index, and lateral shoot length while increasing the number of days to flower. Daminozide alone resulted in a quadratic change in growth index and lateral shoot length while linearly increasing the number of days to flower but with no effect on quality rating. The higher rates of paclobutrazol than were used in the first experiment decreased shoot height and lateral shoot length with no effect on growth index, the number of days to flower, or quality rating. Overall, the best quality ratings and the most compact plants resulted from spray applications of daminozide at 5100 ppm or 7650 ppm and flurprimidol at 150 ppm or 200 ppm, however flurprimidol is not currently registered for application to greenhouse crops but a newer product, Topflor, has the same active ingredient and greenhouse crop labeling.

scholarly journals Shasta Daisy Cultivars Respond Differently to Photoperiod and Vernalization

2007 ◽  
Vol 25 (2) ◽  
pp. 100-104
Author(s):  
J.T. Coleman ◽  
J.R. Kessler ◽  
G.J. Keever ◽  
J.L. Sibley
Keyword(s):  
Growth Index ◽  
Plant Size ◽  
Height Growth ◽  
Practical Application ◽  
Shoot Height ◽  
Shoot Number ◽  
Quality Rating ◽  
Short Days

Abstract Inconsistencies have been reported in the role of vernalization and photoperiod on growth and flowering of Leucanthemum x superbum Bergmans ex J. Ingram cultivars. Five cultivars were used to determine the effects of vernalization and photoperiod on days to flower, shoot height, growth index, flower shoot number, and quality rating. Plants received 0, 3, 6, 9, or 12 weeks of vernalization time (VER) at 4.4C (40F) and afterward were placed under either natural short days (SD) or night-interrupted lighting (NIL) in a greenhouse. ‘Becky’ showed an obligate requirement for NIL to flower with 100% of plants flowering under NIL and 0% of plants flowering under SD regardless of VER. Vernalization for 6 weeks before NIL increased shoot height, growth index, flower shoot number, and quality rating but the fewest days to flower occurred after 12 weeks of VER. ‘Silver Princess’, ‘Snow Cap’, ‘Snow Lady’, and ‘Summer Snowball’ showed a facultative requirement for NIL to flower. Plants under NIL flowered earlier, were larger, had more flower shoots, and had a higher overall quality rating than plants under SD. Shoot height and growth index were highest under NIL after 3 and 6 weeks of VER, flower shoot number was highest after 3 to 9 weeks of VER, but days to flower was least after 12 weeks of VER. Therefore, NIL after 3 or 6 weeks of VER would maximize plant size and quality for practical application in the cultivars studied but result in more DTF when compared to 12 weeks of VER.

scholarly journals Plant Growth Retardants Affect Growth and Flowering of Achillea × ‘Coronation Gold’

2008 ◽  
Vol 26 (1) ◽  
pp. 24-28 ◽  
Author(s):  
J.R. Kessler ◽  
G.J. Keever
Keyword(s):  
Plant Growth ◽  
Growth Index ◽  
Plant Size ◽  
Growth Retardant ◽  
Growth Retardants ◽  
Shoot Height ◽  
Stage Of Development ◽  
Quality Ratings ◽  
Plant Growth Retardants

Abstract An experiment was conducted to determine the effects of several widely used plant growth retardants on plant size and flowering of Achillea × ‘Coronation Gold’. Plants in 10 cm (4 in) pots were grown in a greenhouse and treated with B-Nine at 0, 2550, 5100, or 7650 ppm; Cycocel at 0, 767, 1534, or 2301 ppm; B-Nine/Cycocel at 0, 1275/1534, 2550/1534, or 3825/1534 ppm; Sumagic at 0, 11, 22, 33, 44, or 55 ppm; Bonzi at 0, 32, 64, 96, 128, or 160 ppm; or Cutless at 0, 40, 80, or 120 ppm as a spray 1 week after vernalization. B-Nine, Cycocel, B-Nine/Cycocel, Sumagic, Bonzi, and Cutless reduced shoot height and growth index by 36 and 26%, 39 and 27%, 61 and 41%, 75 and 52%, 52 and 36%, and 75 and 51%, respectively, with the highest rate of each. B-Nine, Cycocel, B-Nine/Cycocel, and Sumagic, but not Bonzi or Cutless, increased the number of days to open inflorescence by 3-5 days with increasing rate. Sumagic, Bonzi, and Cutless reduced inflorescence diameter by up to 15, 18, and 14%, respectively but not B-Nine, Cycocel, or B-Nine/Cycocel. The highest quality ratings of 2.8 to 3.0 were found with B-Nine/Cycocel at 3825/1534 ppm, Sumagic at 22 and 33 ppm, and Bonzi at 64 ppm. Differences between the results in this study and earlier studies implicate the possible impact of differences in experimental environments, container size, or stage of development when the plant growth retardant treatments were applied.

Effects of Plant Growth Retardants and Application Timing after Shearing on Growth and Flowering of Coreopsis verticillata `Moonbeam'

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 522a-522
Author(s):  
J. Raymond Kessler ◽  
Gary J. Keever
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Index ◽  
Market Quality ◽  
Growth Retardants ◽  
Application Timing ◽  
Quality Rating ◽  
Plant Growth Retardants ◽  
Herbaceous Perennial ◽  
Short Days

Coreopsis verticillata `Moonbeam' is a herbaceous perennial that may grow too tall in small containers under greenhouse conditions for market acceptance, and therefore may benefit from plant growth retardants. Rooted terminal cuttings produced under short days were given a terminal pinch and transplanted to 10 cm pots. Cuttings were sheared to 6 cm above the pot rim 4 weeks later. Growth retardant treatments consisting of ancymidol drench at 0, 0.125, 0.25, or 0.375 mg a.i./pot; paclobutrazol drench at 0, 0.125, 0.25, or 0.375 mg a.i./pot; daminozide spray at 0, 2550, 5100, or 7650 mg·L–1; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 mg·L–1; or flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 mg·L–1 were applied 10 days after shearing. Night-breaking lighting using incandescent bulbs was started the same day. The highest rate of ancymidol, paclobutrazol drench, daminozide, and flurprimidol decreased plant height compared to controls by 36, 30, 21, and 36%, respectively. Paclobutrazol sprays were not effective. A market quality rating of four or higher (good, salable) was given to plants treated with daminozide at 5100 or 7650 mg·L–1 or flurprimidol at 150 or 200 mg·L–1. A second experiment was conduced to determine application timing. A daminozide spray at 0, 2550, 5100, or 7650 mg·L–1 was applied 0, 3, 6, 9, 12, or 15 days after shearing. Plant height, growth index and lateral shoot length were least and market quality rating highest when 5100 or 7650 mg·L–1 of daminozide was applied between 6 and 9 days after shearing.

scholarly journals End-of-Day Lighting Effects on Herbaceous Perennials Grown Under Night Interrupted Lighting Outdoors in the Southern United States

2013 ◽  
Vol 31 (1) ◽  
pp. 1-6
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson
Keyword(s):  
Stem Elongation ◽  
Growth Index ◽  
Height Growth ◽  
Shoot Length ◽  
Southern United States ◽  
Flower Number ◽  
Herbaceous Perennials ◽  
Natural Photoperiod ◽  
Quality Rating ◽  
Almost All

A study was conducted in 2004 to determine if end-of-day lighting (EOD) alone or in combination with night-interrupted lighting (NIL) could be used to suppress stem elongation of ‘Goldsturm’ coneflower (Rudbeckia fulgida Aiton ‘Goldsturm’), ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) and ‘Early Sunrise’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Early Sunrise’) when grown outdoors under nursery conditions in the southern U.S. without negating the benefits of earlier flowering from NIL. End-of-day lighting, NIL, and the combination of the two treatments accelerated time to flowering of all three cultivars compared to that of plants under a natural photoperiod (NP); however, rudbeckia flowered quicker when exposed to NIL or NIL + EOD than when grown under EOD only. Height of rudbeckia grown under EOD or NIL was greater than that of plants grown under NP, whereas ‘Moonbeam’ coreopsis exposed to EOD, NIL or EOD + NIL were similar in height and taller than plants grown under NP. Height of ‘Early Sunrise’ coreopsis was minimally affected by treatments, except that plants under EOD were shorter than those under EOD + NIL. Growth index, flower number, shoot length and quality rating were similar in almost all cases for plants of the three cultivars when grown under EOD lighting, NIL, or EOD + NIL. These results indicate EOD was ineffective in suppressing height growth and provided no benefit, either alone or in combination with NIL, over NIL alone in the accelerated production of these cultivars outdoors under nursery conditions.

scholarly journals Vegetative Responses of Apple Trees Following Benzyladenine and Growth Regulator Sprays

1990 ◽  
Vol 115 (3) ◽  
pp. 400-404 ◽  
Author(s):  
Duane W. Greene ◽  
Wesley R. Autio
Keyword(s):  
Shoot Growth ◽  
Shoot Length ◽  
Growth Retardants ◽  
Lateral Shoot ◽  
Lateral Branching ◽  
Lateral Shoots ◽  
Bud Size ◽  
Chemical Inhibition ◽  
Terminal Buds ◽  
Positive Effect

Benzyladenine (BA) stimulated lateral branching on young apple (Malus domestica Borkh.) trees at concentrations as low as 100 mg·liter-1. BA reduced lateral shoot length indirectly through increased intersboot competition, whereas daminozide reduced lateral shoot growth as a direct effect of the chemical inhibition. Daminozide reduced the number of spurs that were induced by BA to grow into lateral shoots. BA reduced the size of terminal buds on spurs that were stimulated to grow into lateral shoots. When daminozide was included with BA, spur quality was increased, as determined by Increased bud size. The positive effect of daminozide on BA-treated spurs was indirect, and other growth retardants used in combination with BA may be equally effective at improving spur quality. It may not be possible to stimulate lateral branching with BA on young trees just coming into production without causing an unacceptable amount of thinning. However, on bearing `Empire' trees, lateral shoot growth was increased with BA while still achieving an appropriate level of thinning. In general, there was no advantage to applying BA in a split application. Chemical names used: N-(phenylmethyl)-1H-purine-6-amine [benzyladenine (BA)]; butanedioic acid mono(2,2-dimethylhydrazide) (daminozide).

Nursery Fertilization and Top Pruning of Slash Pine Seedlings

1990 ◽  
Vol 14 (2) ◽  
pp. 73-76 ◽  
Author(s):  
Mary L. Duryea
Keyword(s):  
Crop Yield ◽  
Field Performance ◽  
Growing Season ◽  
Height Growth ◽  
Slash Pine ◽  
Shoot Height ◽  
Foliar Nitrogen ◽  
N Concentration ◽  
Pine Seedlings

Abstract Top pruning, growing-season fertilization, and fall fertilization were investigated in a Florida nursery to determine the effects on crop yield, morphology, nutrition, and field performance. Top pruning improved crop yield by reducing the number of cull seedlings. Top-pruned seedlings were smaller in diameter, height, and weight and had an increased number of multiple tops. In the field, top-pruned seedlings had the same survival and height growth, and after 3 years the percentage with multiple tops was the same as nonpruned seedlings. From these results, top pruning seems to be a nondetrimental practice for controlling height and producing a uniform crop in the nursery. Reducing growing-season fertilization slightly decreased shoot height, but not as much as top pruning. Also, these seedlings had reduced foliar nitrogen (N) concentration and content and grew less after 1 year in the field indicating that cutting back on N in the nursery may not be a beneficial way to control height. Fall fertilization in the nursery increased N in seedlings but did not affect growth or survival in the field. South. J. Appl. For. 14(2):73-76.

Effect of seed weight on height growth of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) seedlings in a nursery

1985 ◽  
Vol 15 (6) ◽  
pp. 1109-1115 ◽  
Author(s):  
Frank C. Sorensen ◽  
Robert K. Campbell
Keyword(s):  
Seed Size ◽  
Seed Weight ◽  
Germination Rate ◽  
Plant Size ◽  
Height Growth ◽  
Douglas Fir ◽  
Genetic Makeup ◽  
Practical Implications ◽  
Filled Seeds

Different mean seed weights were produced within each of 10 young Douglas-fir trees by leaving some developing cones unbagged and enclosing others in Kraft paper bags for two different durations. On the average, 10 days in the bag increased filled-seed weight by about 1%. Unbagged cones and cones from the 117-day bagging duration were wind pollinated. Seeds from these cones were, therefore, of comparable genetic makeup and were used in further nursery growth tests. To eliminate the effect of germination rate or time, samples of filled seeds from each treatment on each parent tree were sown as germinant seedlings on one date. Cotyledon number was counted and 1st-year epicotyl lengths and 2nd-year total heights were measured on all seedlings. Seedling volumes were estimated by assuming diameters were proportional to heights. On the average, bagging cones for 117 days increased seed weight by 10.7%, 1st-year epicotyl length by 9.1%, and 2-year total height by 4.0%. All differences were statistically significant. Results were compared with other reports of the relations between seed weight and growth and reasons for inconsistencies were discussed. Size differences were projected to later ages with a growth model and practical implications of long-term seed effects on plant size, of increasing seed size through cultural techniques, and of grading seed lots by size were considered.

Above- and be Bow-ground biomass of precompetitive red pine in northern Michigan

1995 ◽  
Vol 25 (7) ◽  
pp. 1064-1069 ◽  
Author(s):  
David D. Reed ◽  
Glenn D. Mroz ◽  
Hal O. Liechty ◽  
Elizabeth A. Jones ◽  
Peter J. Cattelino ◽  
...  
Keyword(s):  
Aboveground Biomass ◽  
Growth Index ◽  
Tree Height ◽  
Growing Season ◽  
Height Growth ◽  
Red Pine ◽  
Basal Diameter ◽  
Total Height ◽  
Ground Biomass ◽  
Northern Michigan

In 1984, red pine (Pinusresinosa Ait.) plantations were established at three sites in northern Michigan. From 1985 through 1992, 3083 individual trees from these stands were destructively sampled to determine aboveground biomass. The root systems were excavated on a subset of these trees (975 individuals). There were no significant differences in the relationships between either above- or below-ground biomass and groundline diameter and tree height across the range of biomass (3–6720 g for aboveground biomass and 1–319 g for belowground biomass), basal diameter (0.3–10.1 cm), or height (10–417 cm) of the sampled trees. There were also no significant differences in these relationships among the three sites. Relative height growth (the ratio of total height increment in a year and the total height at the beginning of the growing season) was found to have a very well defined maximum that was a function of total height at the beginning of the growing season. This maximum relative growth rate was used to develop a new height growth index that can be used to identify precompetitive red pine that are approaching their potential height growth in field situations.

scholarly journals Cutless Controls Shoot Growth of ‘China Girl’ Holly

1994 ◽  
Vol 12 (3) ◽  
pp. 167-169
Author(s):  
G.J. Keever ◽  
C.H. Gilliam ◽  
D.J. Eakes
Keyword(s):  
Growth Inhibition ◽  
Shoot Growth ◽  
Growth Index ◽  
Dry Weight ◽  
Shoot Length ◽  
Single Application ◽  
Growing Seasons ◽  
Shoot Dry Weight ◽  
Production Growth ◽  
Container Production

Abstract Ilex x meserveae ‘China Girl’ plants were sprayed with a single application of different rates of Cutless (flurprimidol) during container production. Growth index, shoot length and shoot dry weight decreased with increasing rates of Cutless. Growth index of plants treated with 500 ppm Cutless was about 17% less than that of control plants 120 days after treatment, but were similar after the spring flush the following year. Growth inhibition persisted for at least two growing seasons when plants were treated with rates of 1500 to 2500 ppm; foliage of these plants was smaller and more cupped than that of control plants. Treated plants were noticeably more compact and uniform, and foliage was darker green than that of control plants.

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