scholarly journals 632 GA4/7 and Light Level Affect Flowering and Plant Height of New Cultivars and Genetic Lines of Aquilegia ×hybrida Sims

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 506D-506
Author(s):  
T.J. Gianfagna ◽  
R.H. Merritt ◽  
J.D. Willmott

Aquilegia cultivars `Songbird Bluebird', `Songbird Robin', `Dove Improved', `Colorado Violet/White' and five cultivars from new experimental genetic lines (`Red and White', `Rose and White #1', `Rose and White #2', `Scarlet and Yellow' and `White') will flower without vernalization, but little is known of their response to light or plant growth regulators. Plants were started from seed on 5 Jan. 1999 and grown in either natural light or 33% shade, and treated with gibberellins (GA4/7) at the seven-leaf stage. Flowering time, number of flowers/plant, and plant height were evaluated through 31 May 1999. All five cultivars from the new genetic lines bloomed during the study. `White', grown in shade and treated with GA4/7, bloomed 2 weeks earlier (115 days) than untreated plants grown in natural light (130 days). `Songbird Robin', treated with GA4/7, bloomed in 146 days, and was the only other cultivar to bloom. Flower numbers were greater in natural light than in 33% shade. GA4/7 increased flowering for four of five cultivars, in the new genetic lines, grown in natural light. In shade, GA4/7 increased flowering for three of five cultivars. Height response to GA4/7 was significant in both natural light and 33% shade. Four of the five cultivars in the new genetic lines were taller when treated. All five of these cultivars were taller when grown in natural light verses 33% shade. `White' and both `Rose and White' cultivars were consistently taller, bloomed earlier and were more floriferous when treated with GA4/7.

2011 ◽  
Vol 33 (spe1) ◽  
pp. 37-47 ◽  
Author(s):  
Terence Robinson

Over the last 60 years, planting densities for apple have increased as improved management systems have been developed. Dwarfing rootstocks have been the key to the dramatic changes in tree size, spacing and early production. The Malling series of dwarfing rootstocks (M.9 and M.26) have been the most important dwarfing rootstocks in the world but are poorly adapted in some areas of the world and they are susceptible to the bacterial disease fire blight and the soil disease complex, apple replant disease which limits their uses in some areas. Rootstock breeding programs in several parts of the world are developing improved rootstocks with resistance to fire blight, and replant disease, and improved cold hardiness and yield efficiency. A second important trend has been the increasing importance of new cultivars. New cultivars have provided opportunities for higher prices until they are over-produced. A new trend is the "variety club" in which variety owners manage the production and marketing of a new unique cultivar to bring higher prices to the growers and variety owners. This has led to many fruit growers being unable to plant or grow some new cultivars. Important rootstock and cultivar genes have been mapped and can be used in marker assisted selection of future rootstock and cultivar selections. Other important improvements in apple culture include the development of pre-formed trees, the development of minimal pruning strategies and limb angle bending which have also contributed to the dramatic changes in early production in the 2nd-5th years after planting. Studies on light interception and distribution have led to improved tree forms with better fruit quality. Simple pruning strategies and labor positioning platform machines have resulted in partial mechanization of pruning which has reduced management costs. Improved plant growth regulators for thinning and the development of a thinning prediction model based on tree carbohydrate balance have improved the ability to produce the optimum fruit size and crop load. Other new plant growth regulators have also allowed control of shoot growth, control of preharvest fruit drop and control of fruit softening in storage after harvest. As we look to the future, there will be continued incremental improvement in our understanding of plant physiology that will lead to continued incremental improvements in orchard management but there is likely to be dramatic changes in orchard production systems through genomics research and genetic engineering. A greater understanding of the genetic control of dwarfing, precocity, rooting, vegetative growth, flowering, fruit growth and disease resistance which will lead to new varieties and rootstocks which are less expensive to grow and manage.


Author(s):  
Jajang Sauman Hamdani ◽  
Sumadi , ◽  
Yayat Rochayat Suriadinata ◽  
Lourenco Martins

ABSTRACT<br /><br />Use of shade on the cultivation of  potato in medium altitude is expected to reduce both light intensity and temperature, and therefore is more suitable for potatoes to grow in medium altitude. While the use of growth regulators subtances improving the process of assimilate distribution from the leaves to the tuber. Therefore  use of shade followed by plant growth regulators applications are expected to increase of  growth and yield. The objectives of the experiment were to determine growth and yield of  potato cultivar Atlantik grown  at medium  altitude with different types of shading and  plant growth regulators. The experiment was conducted at an experimental station of the Faculty of Agriculture, Padjadjaran University, Jatinangor, Sumedang, at an altitude 685 m asl. The experiment was arranged in  a split plot design  consisting of two factors and three replications. The main plots were types of shading (without shading, paranet 45%, UV polyethylene, and corn plant) and the sub plots were combination of plant growth regulators (benzylaminopurine + paclobutrazol), (benzylaminopurine +chloro choline chloride), benzylaminopurine, paclobutrazol, chloro choline chloride).  The results showed that the effect of interaction between shading and plant growth regulator on growth and yield of the potato were not significant. Paranet shade and corn plant shade  increased plant height, leaf area index, tuber weight per plant, yield  per hectar and tuber grade A of potato cultivar Atlantik. Corn plant shading gave potato yield 21.6 ton ha-1 with 64% grade A tuber. Paclobutrazol decreased potato plant  height,  but  increased  number  of  tuber per plant and yielded highest tuber weight of 702.1 per plant (23.3 ton ha-1 ), with 70.9% grade A tuber.    <br /><br />Keywords: Benzylaminopurine, microclimate, paclobutrazol, temperature


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 852D-852
Author(s):  
Sabrina L. Shaw ◽  
William F. Hayslett ◽  
Eddie B. Williams

A one-time application of fish emulsion 2 days before the application of plant growth regulators (PGR) showed an overriding effect on the growth of pansies. Blue/blotch shades of `Medallion' pansies were placed on a constant feed program of 100 ppm Peat Lite 20N–10P–20K, with half of the pansies receiving an additional one-time supplement of fish emulsion. PGRs and rates included B-Nine, 0.5% (used as the control); uniconazole, 2 and 4 ppm; and paclobutrazol, 16 and 25 ppm. Parameters taken included plant height, top fresh weight, top dry weight, days to anthesis, and visual appearance. Significant differences were noted in the plants receiving the supplement for plant dry weight, plant height, and visual appearance. Plants receiving fish emulsion grew taller and denser than those on constant feed alone despite the effects of the PGRs.


2015 ◽  
Vol 25 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Amir Rezazadeh ◽  
Richard L. Harkess

Purple firespike (Odontonema callistachyum), native to Central America, has potential for use as a new flowering potted plant. The effects of number of pinches (zero, one, or two) and number of cuttings (one, two, or three) per 6-inch pot were evaluated on the control of plant height. Plant height was suppressed as the pinch number increased. The greatest reduction was recorded with one cutting per pot and two pinches. The maximum number of branches per pot was recorded with two pinches and three cuttings per pot. In a second experiment, plant growth regulators (PGR) were also tested for efficacy of height control; 2 weeks after pinching, foliar sprays of paclobutrazol, flurprimidol, daminozide, chlormequat, and a tank-mix of daminozide + chlormequat or media drenches of paclobutrazol, uniconazole, or flurprimidol were applied. Plant height, leaf area, and leaf dry weight were recorded at 3, 6, and 9 weeks after PGR application. Maximum height control was obtained with uniconazole drench at 8 ppm, resulting in plants 22 cm tall, 61% shorter than the untreated control (56 cm); however, it resulted in severe leaf distortion. Plant height was 56% and 46% shorter than the control using drenches of paclobutrazol at 30 ppm and flurprimidol at 15 ppm, respectively. Daminozide spray at 2000 ppm and tank-mix of daminozide + chlormequat at 4500/1500 ppm suppressed stem elongation by 20.3% and 19%, respectively. Plants treated with paclobutrazol drench at 30 ppm reduced leaf area and leaf dry weight compared with other PGRs. Chlormequat spray at tested concentrations was ineffective for controlling firespike plant growth. The most attractive potted plants were produced using a drench application of paclobutrazol at 10 or 15 ppm.


HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 563B-563a ◽  
Author(s):  
Mauricio J. Sarmiento ◽  
Jeff S. Kuehny

Curcuma alismatifolia `Chiang Mai Pink' is a tropical perennial from the Zingiberaceae family with attractive flowers that make it useful as potted plant. Curcuma alismatifolia produces a tall inflorescence resulting in an unmarketable plant due to excessive height. Rhizomes of C. alismatifolia were soaked for 10 minutes in GA at concentrations of 0, 100, 200 or 500 ppm. The same plants were drenched with paclobutrazol at 0, 2, 3 or 4 mg a.i./container when shoots were 10 cm. GA significantly delayed rhizome emergence and flowering and reduced flower height. Paclobutrazol significantly reduced height; however, greater concentrations must be applied to obtain a marketable plant height. Number of flowering stems, postproduction life, and postproduction stretching were not affected by GA or paclobutrazol. Curcuma alismatifolia had an excellent postproduction life (4.64 ± 0.28 weeks) with little postproduction stretching (2.27 ± 0.38 cm).


Author(s):  
S. А. Pryplavko ◽  
V. M. Gaviy

Scientific research suggests that winter wheat cultivation technologies can be regulated by plant growth regulators. These substances have a complex effect on growth and development and facilitate plant growth and crop capacity. Three-year field studies were carried out using plant growth regulators of Azotophyte, Amber acid and Vympel to determine the dynamics of plant growth rates and their productivity. This made it possible to observe the influence of growth regulators before sewing and to establish their effectiveness at all stages of plant development. Seeds of winter wheat of the variety Jubiwata were treated with solutions of the substances under analysis. The experimental area was 40 m². The study demonstrated that the growth regulators do not influence the field germination rate of plants, but the percentage of germination was quite high in both control and experimental variants. As for the rates of plant height and root length, the first measurement of the average height of winter wheat plants in autumn demonstrated that Vympel was the most efficient. Its indicators exceeded the control variant by 3.4%. After the second measurement, the plant height increased in all variants. The fourth spring measurement showed that the most powerful was the effect by Amber acid. This compound significantly inhibited plant growth compared to other growth regulators and controls. The investigated plant growth regulators have a positive influence on the processes of root development of winter wheat plants in both autumn and spring time. This feature will provide a better nutrition of the plants. The weight of the dry matter after the first weighing was greater in the control and the variant treated with Nitrogen. The fourth weighing showed that the best effect on the dry matter mass was found by Azotophyte, which contributed to the increase of this indicator twice as much compared to the control. Amber acid, when used for pre-sowing seed treatment, exceeded the control value by 1.8 times. Stronger effect on the percentage of dry matter in the plant sample was found only by Vympel, under the influence of which this indicator was greater by 9 units compared to the control. The use of synthetic growth regulators significantly increases the productivity of winter wheat, namely the length of the complex ear, the number of grains and the weight of the compound ear. Thus, research has shown that plant growth regulators Azotophit, Amber acid and Vympel facilitate the growth and productivity of winter wheat plants of the Juvivat variety. Winter wheat crops can be treated with these substances before sowing. Determining the highest efficiency of each individual regulator, as well as the possibility of combining them to improve plant growth processes, requires further research.


2018 ◽  
Vol 28 (4) ◽  
pp. 445-449
Author(s):  
Shawn D. Lyons ◽  
William B. Miller ◽  
H. Christian Wien ◽  
Neil S. Mattson

When grown in containers, pineapple lily (Eucomis sp.) can produce excessively long foliage and tall scapes, particularly in cultivars with tall pineapple lily (Eucomis comosa) parentage. Height control, through the use of plant growth regulators (PGRs), is necessary to improve crop quality of potted pineapple lily. In year 1 of these trials, bulbs of cultivars Reuben, Tugela Jade, and Tugela Gem were given substrate drenches of flurprimidol or paclobutrazol, each at 2, 4, or 6 mg per 6-inch pot. Drenches were applied at the “visible inflorescence” stage. As concentration increased, scapes were generally shorter in all cultivars for both PGRs, but there was no effect on foliage length or production time. At the rates tested, the reduction in scape length was insufficient to produce marketable plants of the three cultivars. In the second year, substrate drenches were applied at an earlier stage than in year 1, at “leaf whorl emergence,” when shoots were about 7 cm tall. The PGR treatments were notably more effective at controlling plant height in the second year. As concentration increased, scape and foliage length was reduced relative to the controls in all three cultivars for both PGRs. For all cultivars, inflorescence leaning and toppling were sharply reduced at all application rates compared with untreated controls. The reduction in plant height observed in year 2, particularly in plants treated with 4 or 6 mg/pot, resulted in plants with compact scapes and foliage proportional with their 6-inch containers.


1994 ◽  
Vol 12 (3) ◽  
pp. 150-154
Author(s):  
Joyce G. Latimer ◽  
Sherrod A. Baden

Abstract In 1988, spray applications of 3.5 or 7 ppm paclobutrazol, 1500 ppm chlormequat, or 200 ppm ancymidol were applied to seed geraniums (Pelargonium x hortorum L. H. Bailey ‘Ringo White’ and ‘Ringo Rose’) to determine effects on growth in the greenhouse and the subsequent growth and performance of treated plants in the landscape. All growth retardants reduced stem length and shoot dry weight as well as time required for flowering, while branching was increased relative to the untreated plants. Flowering in the landscape was increased by all growth regulator treatments at 4 weeks after planting but was generally not different from the untreated plants at 6 weeks after planting. Plant height and width were reduced by all treatments for both cultivars, relative to untreated plants, at 4 weeks after planting. However, only 7 ppm paclobutrazol reduced height and width of ‘Ringo White’ plants at 6 weeks after planting. Plant height, but not width, was reduced by all treatments for ‘Ringo Rose’ at 6 weeks after planting. In 1989, seedlings of ‘Ringo Rose’ were treated with 3.5, 7, 16, 40, or 80 ppm paclobutrazol or 1500 ppm chlormequat or 200 ppm ancymidol. Seedling growth was excessively reduced by 40 or 80 ppm paclobutrazol. Time required for flowering was not reduced by growth regulators in 1989. Landscape performance under conditions of excess rain was not improved by plant growth regulators and the height of plants treated with 16, 40 or 80 ppm paclobutrazol was still less than that of the untreated plants at 12 weeks after planting. Only chlormequat controlled plant growth in the greenhouse without delaying the resumption of growth in the landscape.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 823D-823 ◽  
Author(s):  
Rajendra P. Maurya* ◽  
Champa lal Nagda*

In a field experiment, uniform sized corms of gladiolus (Gladiolus grandiflorus L. cv. Oscar) were planted in last week of October at a distance of 30 cm. between rows and 20 cm. between plants. The effect of GA (50, 100 ppm), Cycocel (500, 1000) and NAA (50, 100 ppm) on gladiolus plants. It was concluded that foliar application of 100 ppm GA3 at 45 days after corm planting has shown superiority in all vegetative, floral characters and corm & cormel yield viz., plant height (128.53 cm), number of leaves (8.57) per plant, spike length (108.33 cm), spike weight (128.87 g), number of florets (17.60) per spike, size of second florets (15.07 cm), number of spikes (1.67) per plant, size of largest corm (7.52 cm), number of corms (1.80) per plant, number of cormels (11.53) per plant and weight of corms (79.33 g) per plant. Whereas, a highest longevity of florets opening or survival on spike (20.33 days) was recorded in 1000 ppm Cycocel.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1125e-1125
Author(s):  
L.G. Sanabria ◽  
S.E. Newman

Various uniconazole (Sumagic™) rates were either sprayed or drenched alone or in combination with 6-BA and GA4+7 (Promalin™) or dikegulac-sodium (Atrinal™) on Hibiscus rosa-sinensis `Brilliant'. The rates of uniconazole were 0, 5, 10, and 15 mg a.i./L; 6-BA and GA4+7, 25 mg a.i./L each; and dikegulac-sodium 1000 mg a.i./L.Plant height was reduced by uniconazole when drenched at rates as low as 5 mg/L and 15 mg/L when sprayed. Dikegulac-sodium slightly counteracted the effects of uniconazole. Uniconazole activity was increased when either sprayed or drenched with application of 6-BA and GA4+7 resulting in greater height reduction.Transpiration and stomatal diffusive resistance of plants drenched with uniconazole alone was erratic; however, when uniconazole was sprayed or drenched and mixed with 6–BA and GA4+7 or dikegulac-sodium transpiration increased.


Sign in / Sign up

Export Citation Format

Share Document