scholarly journals Gibberellic acid in vegetative and reproductive development of Phalaenopsis orchid hybrid genus

2012 ◽  
Vol 30 (1) ◽  
pp. 71-74 ◽  
Author(s):  
Jean C Cardoso ◽  
Elizabeth O Ono ◽  
João D Rodrigues

The flower industry represents about one billion dollars in Brazil and the development of techniques aimed at flowering control is required. This study evaluated the influence of gibberellic acid (GA3) on the vegetative and reproductive development of young plants of Phalaenopsis FSNT 'Dai-Itigo' hybrid pink color. The application of GA3 was made by foliar sprays at concentrations of 0, 125, 250, 500 and 1,000 mg L -1. The length of leaves increased significantly when using GA3 at low concentrations, but leaf width decreased. The application of GA3 at 125 mg L -1 showed the best results for the promotion of flowering and flower quality of this orchid hybrid. In this treatment, about 50% of plants treated with GA3 flowered about 6-12 months before the plants that were non-treated with this plant growth regulator. The quality of flowering and flowers was best with 125 mg L -1 GA3.

2004 ◽  
Vol 44 (3) ◽  
pp. 343 ◽  
Author(s):  
A. C. Rath ◽  
A. J. Prentice

The effects ReTain Plant Growth Regulator (830 g in 1000 L water/ha) applied to a commercial block of 'Arctic Snow' nectarines 7 days before the first harvest was assessed in relation to harvest delay, fruit size, fruit quality (flesh firmness and brix), as well as the quality of the fruit following export to Taiwan. The untreated block (0.87 ha) and the ReTain-treated block (1.0 ha) were harvested according to the orchard's standard maturation criteria of background colour, size and percent blush colour. Based on picking schedules, the maturation of the ReTain block was delayed by 2.75 days (P<0.05). The fruit continued to grow during this delay and resulted in a 12.3% increase in yield and an increase of 393 packed cartons/ha. There were more (P<0.001) cartons of ReTain-treated fruit packed in grade sizes 69–78 mm diameter and less of smaller size classes (51–66 mm) compared with untreated fruit. The increase in both the number of cartons of class 1 fruit and fruit size on the ReTain block resulted in a Return on Investment (ROI) of 14.7 : 1 with an additional net return of AU$17 655/ha over the untreated block. There was a correlation between fruit size and flesh firmness with larger fruit being firmer than smaller fruit (P<0.001), however, packed ReTain-treated fruit was 3.2 N firmer on average (P<0.001) than packed untreated fruit for all size grades and from all harvests and packs. Brix levels increased (P<0.001) with fruit size but there was no difference (P = 0.568) between ReTain-treated fruit and untreated fruit. Two containers of fruit (early and late picks) were exported to Taiwan. The containers held a temperature of 0.5–2.0°C for the 14–15 day transit time from Australia to Taiwan. ReTain-treated fruit in both containers was 1.7 N firmer (P = 0.022) than untreated fruit upon arrival in Taiwan. After ambient storage (23°C) of fruit from container 1 for 45 h, fruit firmness declined (P<0.001) from an average of 65.7 to 43.2 N and there was no difference (P = 0.826) between treated or untreated fruit. It is concluded that ReTain application to 'Arctic Snow' nectarines can increase financial returns to growers through increased fruit size and quality benefits as well as maintain a higher flesh firmness following export.


2021 ◽  
Vol 39 (2) ◽  
pp. 62-67
Author(s):  
Sean J. Markovic ◽  
James E. Klett

Abstract Moroccan pincushion (Pterocephalus depressus) is a drought-tolerant perennial that is being used in landscapes throughout arid areas of the western United States. This paper describes two experiments researching vegetative cutting production from stock plants. Moroccan pincushion stock plants received foliar applications of gibberellic acid (GA3), benzyladenine, ethephon, or auxin [indole-3-butyric acid (IBA)] plant growth regulators (PGR). Plant growth regulators were applied singularly and in combination with GA3 to determine efficacy on stock plant growth. A propagation study was conducted simultaneously to determine effects of these different PGR treatments applied to stock plants on the rooting of moroccan pincushion cuttings. The stock plant study showed GA3 + benzyladenine application increased cutting production over other PGR treatments. Fresh weight of moroccan pincushion cuttings did not differ among treatments. While cuttings did not differ in dry weight in experiment 1, statistical differences were observed in experiment 2. However, these differences in dry weight did not affect the quality of the cuttings. Cuttings from stock plants treated with GA3 + IBA treatment had the highest numerical growth index [(height + width + width)/3]. Cuttings from stock plants treated with GA3 alone or in combination with another PGR were all greater in average growth index and statistically differed from those without GA3 being applied. PGR treatments did not affect rooting percentages of the cuttings with nontreated stock plant cuttings successfully rooting at an average rate of 95%. However, GA3 + IBA was the only treatment where cuttings had 100% rooting for both experiments, indicating potential rooting benefits. Index words: Plant growth regulator, propagation, Pterocephalus depressus, vegetative cuttings. Species used in this study: Moroccan pincushion [Pterocephalus depressus Archibald]. Chemicals used in this study: gibberellic acid (GA3), benzyladenine, ethephon, indole-3-butyric acid (IBA).


2017 ◽  
Vol 35 (0) ◽  
Author(s):  
J.R.G. QUEIROZ ◽  
A.C. SILVA JR. ◽  
D. MARTINS

ABSTRACT: This study has aimed to evaluate the effect of prohexadione-calcium as a plant growth regulator on growth and quality of Japanese lawn grass, Broadleaf carpet grass and Bermudagrass. The treatments and doses of the prohexadione-calcium tested with two three reapplications were 27.5, 55.0, 110.0, 165.0 and 165.0 g a.i. ha-1, and a control without application of a growth regulator. Visual injury evaluations were performed using a scale of scores and plant height and chipping dry matter were determined. We have evaluated the total thickness of the sod grass, root length and dry matter of this material at the end of the experimental period. The study was arranged in a completely randomized design with four replications. The results were submitted to analysis of variance by F-test and the averages of the treatments were compared by t test at 5% probability. The prohexadione-calcium plant growth regulator was visually selective and reduced shoot growth of the three species of grass and can thus be used in the management of lawns in gardens and sports areas. As for the production of sod grass, the prohexadione-calcium can be recommended for Japanese lawn grass and Broadleaf sod grass, especially doses 165.0+165.0 and 55.0+55.0+55.0 respectively, because they have provided a better quality sod grass. For Bermudagrass, the effect of the treatments was harmful for the quality of sod grass and is not recommended for production purposes.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 662f-663
Author(s):  
J. Lu ◽  
O. Lamikanra

Gibberellic acid, a plant growth regulator commonly sprayed for seedless bunch grape cultivars, was used to spray on the seeded muscadine grape cultivars `Carlos', `Fry', `Higgins' and `Triumph'. GA3 at 100 to 300 ppm were sprayed on leaves and fruit clusters before and after anthesis. The flower/fruit clusters also were dipped into a much higher concentration (1000 ppm) in addition to the sprayed concentration of GA3. Berry weight significantly increased in all the sprayed vines, with a maximal increase up to 50%. Early and more uniform ripening was observed in the cultivar `Triumph'. More than 20% of seedless berries also were found on the GA3-sprayed `Triumph' vines. However, the latter two responses (early ripening and seedlessness) did not occur in other cultivars tested. Similar results also were obtained in the dipping treatments. The results indicated that the seeded muscadine grapes responded well to the GA3 treatments in general, but genotype variation is obvious.


Helia ◽  
2016 ◽  
Vol 39 (65) ◽  
Author(s):  
N.I. Nenko ◽  
N.N. Neshchadim ◽  
E.K. Yablonskay ◽  
K.E. Sonin

AbstractBased on the biological characteristics of sunflower, Krasnodar region is the most favorable area for high and stable yields of this crop in the Russian Federation. However, there is a manifestation of the drought in the summer time that adversely affects the productivity and quality of sunflower seeds. Increased resistance to adverse weather conditions is possible only on the basis of deep studying of the physiological features of formation of productivity and quality of seeds, which is a very urgent task The effect of plant growth regulator furolan on growth, productivity and the formation of physical and chemical indicators of quality of sunflower seeds of the P-453 varieties, the SEC and the RMS selection by VNIIMK were investigated. The treatment of vegetative plants by furolan has activated the growth and biomass accumulation in the stems, improved the photosynthetic activity of plants, leaf area increased, thereby increasing their life expectancy and productivity of photosynthesis. Increased plants productivity reduced their empty grain, increasing the geometric dimensions of the seeds and sunflower kernels, reduced seed husk content, oil content and increased oleic acid content in the oil.


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