DOI: 10.4197/Met. 24-1.4
55
Effect of Treating BOUGAINVILLEAGLABRA with Ethrel, Magnesium and Boron on Vegetative and
Flowering Traits
Ahmad Ibrahim Al-Qubaie
Dept. of Arid Land Agric., Fac. of Meteorology, Environment & Arid Land Agric., King Abdulaziz Univ. Jaddah, Kingdom of Saudi Arabia
Abstract. This study was carried out during 2009 and 2010 seasons for examining the effect of ethrel, magnesium and boron either applied singly or in combinations on growth and flowering aspects of bougainvillea (Bougainvillea glabra). Spraying was done either in vegetative shoot stage or at flowering shoot stage with fully developed thorn inflorescence axis. Growth was greatly improved with spraying boric acid at 0.025 % and or magnesium sulphate at 0.05 %. The maximum values of plant height (111 and 112.7 cm. during both seasons) and leaf area (29 and 29.5 cm2 during both seasons) were recorded with spraying magnesium sulphate at 0.05 % in combined with boric acid at 0.025 % regardless the application of ethrel at vegetative shoot stage. Ethrel had no effect on growth aspects. Ethrel, magnesium and boron treatments effectively advanced time of flowering and promoted number of flowers per plant. Time of flowering (in days) from planting reached 18 days with spraying magnesium, boron and ethrel together at vegetative shoot or flowering shoot stages. The maximum number of flowers per plant (30 and 31 flowers during both seasons) was recorded with using magnesium, boron and ethrel at vegetative shoot stage. Dropping of leaves and flowers was enhanced with using ethrel at flowering shoot stage with fully developed thorn inflorescence. Production of ACC and Ethylen was enhanced with using ethrel lately. Spraying the plants with ethrel at 75 ppm at flowering stage recorded the maximum values of ACC (0.1 g nmole g-1) and ethylene (1.41 and 1.43 nl g-1 h-1 during both seasons). For promoting growth and flower formation of bougainvillea glabra, it is advised to spray the plants once early at vegetative shoot stage (15 days after planting) with magnesium sulphate at 0.05 %, boric acid at 0.025 % and ethrel at 75 ppm.
Introduction
Bougainvillea glabra which belongs to family Nyctagivaceae is an economically important ornamental flower in subtropical and tropical regions. As a valued ornamental shrub- vine use in landscaping is disturbed from hot sunny areas to cool damp coastal region worldwide. It is also popular as a potted plant and in hanging baskets.
Ethrel (2- chloro- ethyl phosphonic acid) is considered a potent promoting compound responsible for enhancing and advancing flowering aspects. This is attributed to its action in releasing ethylene which is responsible in activating hydrolytic and oxidative enzymes involved in degradation of chlorophylls (Leopold, 1960, Moor, 1979, Lavee, 1987;
Nooden, 1988, Prince and Cumningham, 1989, Hoyer, 1995 and Liu and Chang, 2011).
Magnesium is not usually applied to ornamental plants especially cut flowers as a routine matter. Magnesium is vital to the production of chlorophylls and the biosynthesis of carbohydrates as well as the stimulation and enhancement of flowering in most floriculture. The promotion on flowering due to application of magnesium is attributed to the beneficial effect of such nutrient in activating enzymes and the biosynthesis of DNA, RNA as well as increasing the uptake of phosphorus (Nijjar, 1985).
The positive functions of boron on ornamental plants were attributed to its essential roles in translocation of sugars as well as enhancing the formation of meristems, cell division and root development. The beneficial effect of boron on preventing the abortion of flowers, the conversion of starch to soluble sugars and the incidence of different disorders (Nijjar, 1985).
Application of magnesium (El- Sayed, 2007, El- Sherbeny et al., 2007, El- Sayed, 2010 and Mohamed, 2012), boron (Ingels, 1994, Attia, 2001, El- Sayed, 2007 and 2010 and Mohamed, 2012) were very effective in enhancing growth and flowering of horticultural crops.
A great promotion on flowering of horticultural crops was observed with using ethrel (Weltering, 1987, Thimann, 1988, Clark and Kelly, 1991, Serek et al., 1994, Curti- Daiz, 1994, Leao and Assis, 1999 and Mohamed, 2012).
This study was conducted to study the effect of some ethrel, magnesium and boron treatments on vegetative and flowering aspects on Bougainvillea glabra.
Materials and Methods
This study was carried out during 2009 and 2010 seasons on one year old seedlings of potted Taipei Red Bougainvillea glabra in the experimental farm of King Abdulaziz Univ. at Hada Al- Sham, Saudi Arabia. The plants were planted in 18 cm pots filled with 5 kg planting medium containing 1 sand: 1 peat moss each pot contained one seedling.
All the seedlings were pruned to leave 50 cm tall with a mean of 17 nodes. During the experimental period, the plants were thoroughly watered every one to three days when the surface of the soil medium appeared slightly dry. Each pot was fertilized monthly with 3 g N, 3 g P and 2 g K in the sources of ammonium sulphate (20.6 % N), calcium superphosphate (15.5 % P2O5)and potassium sulphate (48 % K2O), respectively.
The experiment included the following eleven treatments:- 1- Control (untreated plants).
2- Spraying ethrel at 75 ppm at vegetative growth stage (after 15 days from planting).
3- Spraying ethrel at 75 ppm at flowering stage (after 25 days from planting) with the thorn- inflorescence axis developed fully (FS1) stage.
4- Spraying magnesium sulphate at 0.05 % at vegetative growth.
5- Spraying magnesium sulphate at 0.05 % at (FS1) stage.
6- Spraying boric acid at 0.025 % at vegetative shoot stage.
7- Spraying boric acid at 0.025 % at (FS1) stage.
8- Spraying both magnesium sulphate at 0.05 % + boric acid at 0.025 % at vegetative shoot stage.
9- Spraying both magnesium sulphate at 0.05 % + boric acid at 0.025 % at (FS1) stage.
10-Spraying magnesium sulphate at 0.05 % + boric acid at 0.025 % + ethrel at 75 ppm at vegetative shoot stage.
11-Spraying magnesium sulphate at 0.05 % + boric acid 0.025 % + ethrel at 75 ppm at (FS1) stage.
Each treatment was replicated three times, ten plants per each. All ethrel and nutrients were sprayed either at vegetative shoot stage or at flowering stage with the thorn- inflorescence developed fully. The control plants were at the vegetative shoot stage and received no ethrel or nutrients. Randomized complete block design was followed.
The following parameters were measured:- plant height (cm), leaf area (cm2), time of flowering (days), number of flowers per plant, percentages of dropping flowers and leaves and content of ACC (1- Aminocyclopropane -1- Carpoxylic acid) (a precursor of ethylene) (nmole g-1) and ethylene (nl g-1 h-1) of the shoots. ACC measurements were determined from 1 cm internodes segments of the tested plants cut from 10 cm below the apical bud (according to Lizada and Yang, (1979).
Three leaves of each treated plant were taken for measuring ethylene production (Wheeler et al., 1996).
Statistical analysis was carried out and new L.S.D test at 0.05 was used to compare the treatment means (El-Nakhlawy. 2010).
Results and Discussion 1- Growth Characters.
It is clear from the data in Table 1 that using ethrel at vegetative growth or at flowering shoot stage once as well as the control treatment significantly produced the lowest values of growth characters in relative to using Mg and or B. using magnesium sulphate was superior than using boric cid in this respect. Mg + B application gave the best results relative to using each nutrient alone. The maximum values of plant high (111 and 112.7 cm. during both seasons) and leaf area (29 and 29.5 cm2 during both seasons) were recorded with spraying magnesium sulphate at 0.05
% in combined with folic acid at 0.025 % regardless the application of ethrel at vegetative growth stage. Similar trend was observed during both seasons.
The beneficial effect of magnesium and boron on enhancing cell division, the biosynthesis and translocation of organic food and enzymes activity surely were reflected on enhancing growth characters.
These results are in harmony with those obtained by El- Sayed (2007) and (2010) and Mohamed (2012).
2- Time of Flowering from Planting.
Data in Table 1 clearly show that single or combined application of Ethrel, magnesium and boron was significantly very effective in advancing time of flowering in comparison with the check treatment.
Application of Ethrel alone or in combinations with magnesium and boron significantly resulted in great promotion on time of flowering relative to using magnesium and or boron without Ethrel. Time of flowering did not alter significantly with varying dates of spraying these materials. The control treatment effectively delayed time of flowering (untreated plants flowered after 41 days from planting during both seasons). Time of flowering was greatly advanced with using Ethrel, magnesium and boron together. Time of flowering (in days) from planting reached 18 days with spraying magnesium, boron and ethrel together at vegetative shoot or flowering shoot stages. These results were true during both seasons.
The effect of Ethrel in releasing ethylene which is in turn activating hydrolytic and oxidative enzymes in degradation of chlorophylls (Lavee, 1987) could explain the present results. The beneficial effect of Mg and B on the biosynthesis of plant pigments and carbohydrates could give explanation for the present results (Nijjar, 1985).
These results are in harmony with those obtained by El- Sayed (2007) and (2010) and Mohamed (2012).
3- Number of Flowers/Plant.
It was significantly enhanced in response to single and combined application of Ethrel, Mg and B in relative to the control treatment.
Application of B, Mg and ethrel, in ascending order enhanced number of flowers per plant. Combined application of ethrel, Mg and B gave the best results relative to application of each material alone. The maximum number of flowers per plant (30 and 31 flowers during both seasons) was recorded when using magnesium, boron and ethrel at vegetative shoot stage. The untreated plants produced the lowest values (11 flowers/ plant during both seasons). These results were true during both seasons (Table 1).
The benefit of ethrel, Mg and B in enhancing C/ N in favour of transformation of vegetative buds to flower ones (Moor, 1979) could explain the present results.
These results are in harmony with those obtained by El- Sayed (2007) and (2010) and Mohamed (2012).
Table 1. Effect of using Ethrel, magnesium and boron on some growth and flowering aspects of bougainvillea plants during 2010 and 2011 seasons.
Treatments
Plant height (cm.)
Leaf area (cm2) from
planting
Time of flowering
(days)
No. of flowers/
plant 2010 2011 2010 2011 2010 2011 2010 2011
Control 71.0 72.9 18.6 19.0 41 41 11.0 11.0
Spraying 75 ppm Ethrel at vegetative
shoots 71.0 73.0 18.5 18.9 22 23 24.0 24.0
Spraying 75 ppm Ethrel at FS1 71.0 73.0 18.5 18.9 22 23 11.0 11.0 Spraying 0.05 % magnesium sulphate at
vegetative shoots 97.0 99.5 28.8 29.2 28 28 18.0 19.0 Spraying 0.05 % magnesium sulphate at
FS1 79.3 81.3 22.9 23.3 28 28 11.0 11.0
Spraying 0.025 % boric acid at
vegetative shoots 91.0 92.8 27.0 27.4 31 31 15.0 17.0 Spraying 0.025 % boric acid at FS1 75.3 76.5 21.0 21.5 31 31 11.0 11.0 Spraying both magnesium and boron at
vegetative shoots
111.
0 112.
7 29.0 29.5 26 27 20.0 21.0 Spraying both magnesium and boron at
FS1 86.0 87.9 25.0 25.5 26 26 11.0 11.0
Spraying Mg + B + Ethrel at vegetative shoots
111.
0 113.
0 29.0 29.5 18 18 30.0 31.0 Spraying Mg + B + Ethrel at FS1 86.0 88.0 25.0 25.5 18 18 11.0 11.0
New L.S.D at (0.05)
FS1 = Flowering shoot stage with the thorn inflorescence axis developed fully.
4- Percentage of Dropping of Flowers and Leaves.
It is evident from the data in Table 2 that foliar application of ethrel, Mg, B either singly or in all combination at flowering shoot stage once gave the highest flowers and leaves dropping in relation to using these materials at vegetative shoots stage. Application of ethrel at flowering shoots stage gave the maximum values of dropping. Similar trend was noticed during both seasons.
The great promotion of ACC and ethylene content during flowering shoot stage due to using ethrel surely were reflected on enhancing dropping of flowers and leaves (Moore, 1979).
These results are in harmony with those obtained by Weltering (1987); Clark and Kelly (1991) and Ingels (1994).
5- ACC and Ethylene Content:
Data in Table (2) reasonably reveal that application of ethrel alone or in combined with both Mg and B at flowering shoots stage significantly was accompanied by enhancing values of ACC and ethylene in relative to using Mg and or B at vegetative shoot stage. Spraying the plants with ethrel at 75 ppm at flowering stage recorded the maximum values of ACC (0.1 g nmole g-1) and ethylene (1.41 and 1.43 nl g-1 h-1 during both seasons). The lowest values were recorded on the plants that were sprayed with Mg and or B as well as the untreated plants. These results were true during both seasons.
Table 2. Effect of using Ethrel, magnesium and boron on dropping of flowers and leaf % as well as ACC and ethylene content of bougainvillea plants during 2010 and 2011 seasons.
Treatments
Flower drop
%
Leaf drop
%
ACC content (n mole g-1)
Ethylene (nl g-1 h-1) 2010 2011 2010 2011 2010 2011 2010 2011
Control 0.0 0.0 4 4 0.08 0.10 1.11 1.15
Spraying 75 ppm Ethrel at
vegetative shoots 0.0 0.0 7 8 0.08 0.10 1.31 1.35 Spraying 75 ppm Ethrel at FS1 4.0 4.0 24 24 0.19 0.19 1.41 1.43 Spraying 0.05 % magnesium
sulphate at vegetative shoots 0.0 0.0 4 4 0.08 0.08 1.10 1.11 Spraying 0.05 % magnesium
sulphate at FS1 1.0 1.0 4 4 0.09 0.08 1.10 1.11 Spraying 0.025 % boric acid at
vegetative shoots 0.0 0.0 4 4 0.09 0.08 1.10 1.11 Spraying 0.025 % boric acid at FS1 1.0 1.0 4 4 0.09 0.09 1.10 1.11 Spraying both magnesium and
boron at vegetative shoots 0.0 0.0 3 3 0.10 0.10 1.10 1.11 Spraying both magnesium and
boron at FS1 1.0 1.0 3 3 0.11 0.11 1.11 1.15
Spraying Mg + B + Ethrel at
vegetative shoots 0.0 0.0 7 8 0.08 0.09 1.31 1.35 Spraying Mg + B + Ethrel at FS1 4 4 24 24 0.18 0.18 1.41 1.43 New L.S.D at (0.05)
FS1 = Flowering shoot stage with the thorn inflorescence axis developed fully.
These results might be attributed to the effect of ethrel in releasing ethylene and other procures.
These results are in agreement with those obtained by Hoyer (1995) and Liu and Chang (2011).
Finally, spraying bougainvillea glabra plants once at vegetative shoot stage with ethrel at 75 ppm, magnesium sulphate at 0.05 % and boric acid at 0.025 % is suggested to be beneficial for promoting growth and flowering aspects.
Acknowledgement
I would like to express my sincere gratitude to the staff members of Hada Al- Sham Agricultural Research Station K.A.U especially Dr.
Shareef Hindi for his assistance and patience during the collection of samples of this work.
References
Attia, K.K. (2001) Influence of filter mud cake, elemental sulphur application and micronutrients fertilization on yield and nutrient content of onion. Assiut J. of Agric. Sci., 32(5): 116-124.
Clark, D.G. and Kelly, J.W. (1991) Postharvest quality characteristics of cultivars of potted rose in response to holding conditions cytokinins. Hort. Sci. 26(9): 1195-1197.
Curti-Daiz, S.A. (1994) Effect of gibberellic acid, Ethrel and foliar urea on the vegetative and reproductive development of orange Valencia. Proc. of the Inter. Amer. Soc. Tropical Hort., 38: 70-71.
El- Sayed, M.H. (2007) Response of Ewaise mango trees to foliar application of boron. M. Sc.
Thesis Fac. of Agric. Minia Univ. Egypt.
El- Sayed, M.H. (2010) Beheviour of Ewaise mango trees to foliar application of some nutrients and seaweed extract Ph. D. Thesis Fac. of Agric. Minia Univ. Egypt.
El- Sherbeny, S.E., Khalil, M.Y. and Hussein, M.S. (2007) Growth and productivity of rue (Ruta graveolens) under different foliar fertilizers application. J. of Applied Sci. Res., 3(5): 399-407.
Hoyer, L. (1995) Investigations of the ethylene build up during transport of pot plants in controlled temperature trucks. Post. Boil. Tech., 5: 101-108.
Ingels, J.E. (1994) Ornamental Horticultural Sciences, Operation & Management. 2nd Ed. ITP Delmar Publishers Inc. pp: 1-410.
Lavee, S. (1987) Usefulness of growth regulators for controlling vine growth and improving grape quality in intensive vineyards. Acta Nort., 205: 89-108.
Lizada, M.C.C. and Yang, S.F. (1979) A simple and sensitive assay for 1- aminocycloprpoane 1- carboxylic acid. Anal. Biochem., 100: 140-145.
Leao, P.C.S. and Assis, J.S.D. (1999) Effect of Ethephon on colour and quality of Red Globe grape in the San Francisco Valley. Revista Brasilia de friuticultra, 21(1): 84-87.
Liu, F.Y. and Chang. Y.S. (2011) Ethephon treatment promotes formed formationin bougainvillea. Botanical studies 52: 183-189.
Leopold, A.C. (1960) Auxins and Plant growth. Univ. of California Press, Berkeley Los Angeles, p. 229, U.S.A.
El-Nakhlawy, F.S. (2010) Statistical Design and Analysis of the experinments in Scientific Reserch. Sci. Pub. Center, King Abdulaziz Univ. Saudi Arabia.
Mohamed, S.E. (2012) Response of Banaty grapevines to some ethryl, nutrient and antioxidant treatments. Ph. D. Thesis Fac. of Agric. Minia Univ. Egypt.
Moore, T.C. (1979) Mechanism of Auxin Action Biochemistry and Physiology of plants.
Hormones, Published by Springer, Verlage, U.S.A. pp: 25-50.
Nijjar, G.S. (1985) Nutrition of Fruit Trees. Kalyany Publisher, New Delhi India, pp: 10-70.
Nooden, L.D. (1988) Senescence and Aging in Plants. Academic press. San Diego L.A. pp: 330- 368.
Prince, T.A. and Cumningham, M.S. (1989) Production and storage factors influencing quality of potted Easter lilies. Hort. Sci., 24(6): 992-994. Cf. Hort. Abst. (1990) Vol. 60(6): 4504.
Serek, M., Jones, R.B. and Reid, M.S. (1994) Role of ethylene in opening and senescence of Gladiolus sp. flowers. J. Amer. Soc. Hort. Sci., 119: 1014-1019.
Thimann, K.V. (1985) The interaction of hormonal and environmental factors in leaf senescence.
Biol. Plant, 27: 53-91.
Wheeler, R.M., Peterson, B.V., Sager, J.C. and Knott, W.M. (1996) Ethylene production by plants in a closed environment. Adv. Space Res., 18: 193-196.
Weltering, E.J. (1987) Effect of ethylene on ornamental pot plants: a classification. Sci. Hort., 31: 283-294.
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