scholarly journals Growth Regulators Do Not Increase Onion Bulb Size or Weight Under Greenhouse Conditions

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 599-600
Author(s):  
Vincent M. Russo

Exogenously applied plant growth regulators may affect development of onion, but little is know about how concentration or timing of application can affect bulb grade and quality. Two concentrations of the growth regulators abscisic acid, gibberellic acid, indole-acetic acid, jasmonic acid, kinetin, and maleic acid hydrazide, and water controls, were applied at the 7- and 20-leaf stages to the middle of the leaf whorl in greenhouse grown onion plants. Leaf and bulb weights were lighter, and bulb diameters were smaller, from plants treated with growth regulators applied at the 7-leaf stage than those from plants treated at the 20-leaf stage. Bulbs produced on plants treated with water were the same size, or larger, than those produced on plants treated with individual growth regulators.

2016 ◽  
Vol 69 (1) ◽  
Author(s):  
Marian Saniewski ◽  
Justyna Góraj-Koniarska ◽  
Elżbieta Węgrzynowicz-Lesiak ◽  
Eleonora Gabryszewska

It is known that chilling of <em>Muscari</em> bulbs is necessary for the growth of the inflorescence stalk and flowering, but not for the growth of leaves. Gibberellic acid (GA) accelerated stem growth and flowering in chilled <em>Muscari</em> bulbs. In the present experiment it was shown that in unchilled derooted <em>Muscari</em> bulbs the growth of leaves, but not the growth of the inflorescence stalk, was observed when bulbs were stored in water, GA at a concentration of 50 and 100 mg/L, benzyladenine (BA) at a concentration of 25 and 50 mg/L, or a mixture of GA+BA (50+25 mg/L), but abscisic acid (ABA) at a concentration of 10 mg/L greatly inhibited the growth of leaves. In chilled derooted <em>Muscari</em> bulbs the growth of leaves and inflorescence stalk was observed when bulbs were stored in water or GA, but BA and GA+BA treatments totally inhibited the growth of the inflorescence stalk without an effect on the growth of leaves. These results clearly showed that the growth of leaves and inflorescence stalk in <em>Muscari</em> bulbs are controlled by plant growth regulators in different ways. ABA totally inhibited the growth of leaves and inflorescence stalk in chilled derooted <em>Muscari</em> bulbs. It was shown that after the excision of the inflorescence bud in cultivated chilled <em>Muscari</em> bulbs, the inflorescence stalk died, but application of indole-3-acetic acid (IAA) 0.5% in the place of the removed inflorescence bud induced the growth of the inflorescence stalk. IAA applied under the inflorescence bud inhibited the development of flowers (flower-bud blasting) and induced the growth of the inflorescence stalk below the treatment site. These results are discussed with reference to hormonal regulation of stem (stalk) growth in tulip, narcissus, hyacinth, and <em>Hippeastrum</em>.


10.5219/1126 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 443-448 ◽  
Author(s):  
Oksana Belous ◽  
Julia Abilphazova

We investigated the effect on tangerine of new generation plant growth regulators. The use of drugs in the period of fruit ripening has led to increased 2.0 – 3.7 times abscisic acid (AA) and 1.9 – 4.7% of Indole-acetic acid (IAA) acid in the leaves. Studies have shown that Indole-acetic acid and abscisic acid beginning of a sharp accumulation of their hormones coincides with action of stress factors and growth dormancy period. The use of the regulators had an impact not only on their content in leaves but also on fruit quality. For example, treatment Indole-acetic acid and Obstaktin led to an increase in the fruit of vitamin C. After treatments with plant growth regulators has been a significant decline in the total number of organic acids (up to 2.35% at the option of Melaphen and to 2.50% at Obstaktin, LSD (p ≤0.05) = 0.06). By reducing the content in the fruits of organic acids to all variants increased the sugar-acid index. After each spraying tangerine on the treatment options plant growth regulators has been a significant increase the dry matter. Thus, the positive effect of plant growth regulators on all the quality characteristics of tangerine was shown. In the summer period, the treatment by regulators may have a protective effect, increases the content in plants the content of Indole-acetic acid. The plant growth regulators of new generation have a positive effect on quality of dwarf tangerine. Given that the plants of tangerine in the subtropical zone of Russia each summer have to drought and are losing not only in yield, fruit quality too, new regulators may exert a protective effect, because increases the content in plants is Indole-acetic acid, which activates gene expression of drought resistance.


1970 ◽  
Vol 33 (3) ◽  
pp. 493-502 ◽  
Author(s):  
Sridhar Gutam ◽  
Virendra Nath ◽  
GC Srivastava

A pot experiment was conducted in the rabi (post rainy) seasons of 2001 and 2002 to study the genotypic differences in grain growth rate and endogenous hormonal content in the developing grains of hexaploid and tetraploid wheat. The endogenous hormonal contents of grains in both the ploidy levels had changed in sequence. At 5 days after anthesis (DAA), gibberellic acid (GA3); at 15 DAA (rapid growth phase), indole-acetic acid (IAA); at 25 DAA (dough stage), abscisic acid (ABA) were maximum. At 35 DAA, all the endogenous hormonal level decreased and among the hormones, ABA was highest followed by IAA and GA3. Hexaploids recorded higher concentrations of endogenous hormones (13.38% IAA, 17.89% GA3, and 14.7% ABA) on fresh weight basis and resulted in higher seed weight (56.99 mg/grain) and grain growth rate (0.009 g/g/day) compared to tetraploids (49.08 mg/grain; 0.008 g/g/day) on dry weight basis by better mobilization of photosynthates during grain filling. Key Words: Grain growth rate, hormones, indole-acetic acid, gibberellic acid, abscisic acid. doi:10.3329/bjar.v33i3.1608 Bangladesh J. Agril. Res. 33(3) : 493-502, September 2008


2003 ◽  
Vol 1 (1) ◽  
pp. 59 ◽  
Author(s):  
V. Arbona Mengual ◽  
M.L. Foó Serra ◽  
P. Escrig Marín ◽  
A.J. Marco Casanova ◽  
J.A. Jacas Miret ◽  
...  

Citrus yield and growth are deeply affected by salinity. In the present work we have studied the effectiveness of differentplant growth regulators such as abscisic acid, jasmonic acid and 8’-methylene methyl abscissate in protectingcitrus from salt-induced damage. Plants of Salustiana cultivar grafted onto Carrizo citrange were used for this purpose.Plants were watered with 100 mM NaCl and leaf abscission, ethylene production, chloride accumulation and net photosyntheticrate were measured. Non-treated plants showed a dramatic drop in photosynthetic activity in response tosalinity, an increase in leaf ethylene production and a high abscission rate as a result of a massive leaf chloride accumulation.Plants treated with jasmonic acid or 8’-methylene methyl abscisate did not show any physiological changein response to salt stress. However, plants treated with abscisic acid showed a high reduction in the parameters considered.These results suggest that abscisic acid plays a role in modifying citrus physiological behaviour in responseto salinity and could be helpful in their acclimation to saline conditions


2018 ◽  
Vol 16 (02) ◽  
pp. 58-64
Author(s):  
S Akhter ◽  
T Mostarin ◽  
K Khatun ◽  
F Akhter ◽  
A Parvin

The experiment was conducted in the Horticultural Farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh. Plant growth regulators were applied which had significant effect on yield of sweet pepper (Capsicum annum L.). The experiment consisted of two factors. Factor A: Plant growth regulators (four levels) as G0: Control, G1: Gibberellic Acid (GA3) @ 30 ppm, G2: 4-Chloro Phenoxy Acetic Acid (4-CPA) @ 45 ppm and G3: 4-Chloro Phenoxy Acetic Acid (4-CPA) @ 45 ppm + Gibberellic Acid (GA3) @ 30 ppm and Factor B: Number of spray (three levels) as N0: Control (no spray), N1: two spray, N2: three spray. In case of plant growth regulators, the highest yield (27.77 t/ha) was found from G3 treatment, whereas the lowest (18.87 t/ha) was from G0 treatment. For number of spray the maximum yield (26.0 t/ha) was recorded from N2 treatment, while the minimum yield (19.87 t/ha) was from N0 treatment. The results indicated that the highest yield (31.8 t/ha) was observed from G3N2 treatment combination, while the lowest yield (17.5 t/ha) was from G0N0 treatment combination. Due to combined effect, the highest yield (31.8 t/ha) with net income (Tk/ha 1416558) and BCR (2.46) was observed from G3N2 treatment combination, while the lowest yield (17.5 t/ha) with net income (Tk/ha 433045) and BCR (1.49) from G0N0 treatment combination. Thus, three times spray with (4- Chloro Phenoxy Acetic Acid + Gibberellic Acid) may be recommended for achieving the higher growth, yield and economic benefit of sweet pepper. The Agriculturists 2018; 16(2) 58-64


Author(s):  
Yasar Sajjad

Gladiolus is commercially propagated through corms and occurrence of dormancy in freshly harvested corms creates hindrance in their cultivation. Present study was designed to compare the effect of different chemicals to alleviate the dormancy of corms in a short time. Gladiolus corms were collected from two growing sites and subjected to chemicals methanol, benzylaminopurine (BAP), gibberellic acid (GA3), indole acetic acid (IAA), salicylic acid, potassium nitrate and thiourea at different concentrations alone or in combinations. The treated corms were planted on sand and placed under dark conditions at 26°C. The treatment of 60% methanol in combination with 0.9 mM BAP showed maximum germination (72.71%). Descaled corms showed 85% germination compared to 60.42% scaled corms, while the corms collected from Faisalabad showed better germination 83.75% compared to corms from Rawalakot (61.67%). The application of 60% methanol also induced 29.65% and 42.43% deterioration in scaled and descaled corms, respectively. The treatments of 0.3 mM BAP in combination with 0.6 mM GA3 exhibited 88.33 % germination in corms collected from Faisalabad as compared to 55% in corms from Rawalakot. Overall, application of BAP and GA3 in combination was found effective in shortening the period of dormancy in both cultivars of gladiolus compared to other tested chemicals or growth regulators.


OENO One ◽  
2007 ◽  
Vol 41 (3) ◽  
pp. 141 ◽  
Author(s):  
Christelle Deytieux-Belleau ◽  
Séverine Gagne ◽  
Annie L'Hyvernay ◽  
Bernard Donèche ◽  
Laurence Geny

<p style="text-align: justify;"><strong>Aims</strong>: The objective was to better understand the mechanisms involved in grape ripening that brings about important changes in the physiology and chemistry of the fruit. So we focused on the involvement of two growth regulators: abscisic acid (ABA) and indol-acetic acid (IAA) in controlling grape berry ripening process.</p><p style="text-align: justify;"><strong>Methods and results</strong>: We described the evolution of the two plant growth regulators during the development of cv. Merlot grapes (Vitis vinifera L.). In order to better understand the role of ABA and IAA in the ripening control, these two growth regulators were applied on the grapes at the onset of veraison. The hormonal profile was established on treated berries and different physiological parameters were assayed to evaluate the effects of both applications. The partitioning of both plant growth regulators in nontreated berries showed that ABA and IAA accumulated at the onset of ripening. Moreover, it appeared that endogenous ABA decreased progressively in the flesh while accumulated in the skin from the beginning of the colour change to maturity. The hormonal treatments modified the hormonal profile and several physiological parameters: sugar, acidity, colour, and Botrytis sensibility.</p><p style="text-align: justify;"><strong>Conclusion</strong>: These findings suggest that both treatments have modified the ripening process. Exogenous ABA has induced advancement in grape ripening, while IAA application has delayed this process. These observations support the view that the grape ripening process may be influenced by the hormonal status.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: This study gives new information about the ripening control of the non-climacteric fruits. In grape berries, it provides evidence of a possible co-involvement of ABA and IAA in controlling ripening process.</p>


2016 ◽  
Vol 1 (2) ◽  
pp. 36 ◽  
Author(s):  
J. Lalitha ◽  
Haseena Rafath ◽  
M. Subash

The experiment was undertaken with an objective to investigate the effect of various concentrations of plant growth regulators, i.e., Gibberellic acid (GA3) and Indole 3-acetic acid (IAA) on seed germination of Macrotyloma uniflorum. Seeds were soaked for 12 hours in different concentrations substances (1.0, 2.0, 3.0 and 4.0 mg/L) of IAA, GA3 and control set was soaked only in distilled water.  Three replicates of each treatment with fifty seeds per replicate were arranged for precise physiological analysis. Significant variation was found in all aspects after analysis of variance (ANOVA) of each mean value. After two weeks of seed soaking, it was noted that germination percentages were significantly accelerated by lower concentrations (1 and 2 mg) of used hormones. Amongst the two potential growth regulators, 2 mg/L was found most effective because it showed highest germination percentage for IAA (93%) and GA3 (88%). A great deal of information relating to seed germination practices shows that these plant growth regulators were efficient in overcoming dormancy leading to rapid seed germination. IAA was selected as best hormone in this study, which showed highest seed germination (93%). 


2010 ◽  
Vol 4 (2) ◽  
pp. 94-100
Author(s):  
Arwa A Tawfiq

The level of endogenous free, bound and total auxin (Indol-3-acitic acid, IAA) and gibberellic acid (GA3) were examined in dry bakery yeast. For determination of the levels of these plant growth regulators level, used spectrophotometer. The results show that Saccharomyces cereviciae was produced IAA and GA3. IAA level was 29.86 µg/ml, 198 µg/ml at 222nm and 280nm wavelengths respectively and GA3 level was 799 µg/ml at 254nm.


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