EFFECT OF FOLIAR SPRAYS OF BIOREGULATORS ON GROWTH AND FLOWERING IN GLADIOLUS

Transcription

1 Indian J. Agric. Res., 47 (3) : , 2013 AGRICULTURAL RESEARCH COMMUNICATION CENTRE / indianjournals.com EFFECT OF FOLIAR SPRAYS OF BIOREGULATORS ON GROWTH AND FLOWERING IN GLADIOLUS T. Padmalatha*, G. Satyanarayana Reddy, R. Chandrasekhar, A. Siva Shankar 1 and Anurag Chaturvedi 2 College of Horticulture, Hyderabad , India Received: Accepted: ABSTRACT Effect of different plant growth regulator sprays (GA 3, TIBA, CPPU and BR) on growth and flowering of two gladiolus cultivars Darshan and Dhiraj was investigated for two consecutive years, and Growth regulators were sprayed at 3 rd and 6 th leaf stage. Cv. Darshan differed significantly with cv. Dhiraj in respect to plant height, leaf area and flowered earlier. GA ppm followed by brassinosteroid (BR) 10 ppm recorded maximum plant height, number of leaves and leaf area during vegetative growth and resulted in earlier flowering. TIBA 100 ppm, TIBA 50 ppm and control recorded significantly minimum leaf area and showed delayed flowering. Cv. Dhiraj recorded maximum percentage of plants flowered than the cv.darshan. Cv. Darshan recorded significantly highest spike length and inter floret length and minimum days to wilting of spike over the cv. Dhiraj. Cv. Dhiraj was significantly superior over cv. Darshan in respect of number of florets per spike and longevity of spike. Maximum spike length and weight, number of florets per spike and spike field life were recorded with GA ppm. Lowest values in respect of flower parameters were recorded with TIBA treatments and control. Key words: Brassinosteroids, CPPU, Flowering, Gladiolus, GA 3,. INTRODUCTION Gladiolus is one of the most important commercial bulbous cut flower crops both in India and abroad. It occupies an important position among cut flowers due to its attractive spikes, sweet fragrance and high economic value. The spikes have variety of colours with long lasting life and withstand long distance transport and are highly used in herbaceous boarders, pots, vase and floral decorations. In the recent past, the productivity of this flower has increased several folds which could be attributed to the introduction of high yielding varieties and adoption of improved package of practices. Of the various improved technologies, plant growth regulators play a vital role in manipulating the plant growth and quality of flower and increasing flower yield. Favourable effect of traditional plant growth regulators like gibberellins and tri iodo benzoic acid (TIBA) on growth and flowering in gladiolus was reported by different workers in different parts of the country (Rajiv Kumar et al., 2002; Tawar et al., 2003; and Devi et al., 2007). But there was no organized research on the effect of new class of plant growth regulators viz., brassinosteroids (BR) and 2-chloro 4-pyridyl phenyl urea (CPPU) on growth and flowering of gladiolus in India as well as i n abroad. The present investigation is aimed to ascertain the effect of foliar sprays of BR, CPPU along with GA 3 and TIBA on growth and flowering in two gladiolus cultivars, Darshan and Dhiraj. MATERIALS AND METHODS The experiment was carried out at Herbal Garden, Rajendranagar, H yderabad for two consecutive years, and In the study, corms of gladiolus cultivars Darshan and Dhiraj were used. There were 9 growth regulator treatments viz., GA 3 (100 and 150 ppm), TIBA (50 * Corresponding author gandhamlatha@yahoo.com, 1 College of Agriculture, ANGRAU, Hyderabad , 2 College of Home Science, ANGRAU, Hyderabad

2 and 100 ppm), CPPU (2.5 and 5.0 ppm), BR (5.0 and 10.0 ppm) and control (water spray) each replicated thrice in factorial randomized block design. Corms were planted at a spacing of 30 cm x 20 cm and at a depth of 5 cm in September. Treatments were imposed as foliar sprays at 3 rd and 6 th leaf stage. Well decomposed farmyard manure at 10 t ha -1 was incorporated into all the experimental plots uniformly as basal application. N, P, and 200:200:300 kg/ha were applied in the form of urea, single super phosphate and muriate of potash respectively. Urea was applied in 3 splits, the first dose as basal application and other two split doses at 30 and 60 days after planting. The entire dose of single super phosphate and muriate of potash were applied at the time of planting as basal dose. Standard cultural practices were followed during the entire crop period for all the experimental plots. Observations on growth and flowering attributes were recorded. Data were subjected to analysis of variance as applicable to factorial randomized block design. RESULTS AND DISCUSSION Data presented in the Tables 1, 2 and 3 indicates that the cv. Darshan was found to be superior in respect of plant height and leaf area over the cv. Dhiraj. With respect to number of leaves per plant, non significant differences were observed between the cultivars during both the years of study. It was noticed that in both the cultivars foliar sprays of plant growth regulators increased the vegetative growth at higher concentrations when compared to lower concentrations. Different growth regulator treatments did not influence plant height, number of leaves and leaf area at 35 DAP. However, at 65 DAP, production of more number of leaves and significantly maximum plant height and leaf area was with higher concentrations of GA 3 and BR. Tawar et al. (2003) reported that vegetative growth increased with increasing dose of GA 3 in gladiolus cv. Jester. Lowest plant height was recorded with TIBA after two foliar sprays. Among all the plant growth regulators, GA 3 played a vital role in improvement of vegetative growth characters of gladiolus plants. In both the cultivars highest vegetative growth was observed with GA 3 at 150 ppm. This might be due to the fact that it enhances Vol. 47, No. 3, 2013 TABLE 1: Effect of foliar sprays of plant growth regulators on plant height (cm) in gladiolus cultivars Darshan and Dhiraj at 35 and 65 DAP. 193

3 194 INDIAN JOURNAL OF AGRICULTURAL RESEARCH cell division by promoting DNA synthesis in cells. Singh et al. (2002) noticed an improvement in all growth parameters with increasing level of GA 3. The increase in vegetative growth characteristics as a result of GA 3 application is also in close agreement with the findings of Pranav Rana et al. (2005). The production of more number of leaves and maximum plant height by GA ppm might be due to rapid growth and differentiation through endogenous auxins. Gibberellins cause stem elongation which may not be due to increased number of nodes and internodes but results from rapid elongation of internodes due to both cell division and cell elongation. This might be the reason that GA ppm treatment although increased the number of leaves significantly over control at 65 DAP, it was on a par with BR 10 ppm, CPPU 5 ppm and GA ppm. Similarly, the effect of GA 3 in increasing plant height was also on a par with BR 10 ppm treatment. Increase in plant height, number of leaves and leaf area with GA 3 treatment has also been reported by Pranav Rana et al. (2005) in gladiolus. BR 10 ppm increased plant height, number of leaves and leaf area significantly at 65 DAP and was found on a par with GA ppm. Mandava and Thompson (1983) reported that gibberellins caused only elongation of the upper internodes but, BRs characteristically evoked both cell elongation and cell divison resulting in elongation, swelling, curvature and splitting of second internode in the bean second internode bioassay. Such activity of BR is called brassisin activity. In all the bioassays, it was found that BRs produce acti vity at concentrations much lower than those effective for gibberellins. Our results are comparable with that of Braun and Wild (1984) who found that BR stimulated leaf elongation in wheat and that of Gregory (1981) in brassisin treated barley seeds. Vardhini and Rao (2004) stated that the growth promotion in tomato due to BR application was associated with elevated levels of nucleic acids, soluble proteins, reducing sugars, non-reducing sugars and starch. Huang et al. (2009) concluded that BRs promote photosynthesis and growth by positively regulating synthesis and activation of a variety of photosynthetic enzymes including Rubisco. CPPU, a synthetic cytokinin at 5 ppm concentration increased plant height, number of leaves and leaf TABLE 2: Effect of foliar sprays of plant growth regulators on number of leaves in gladiolus cultivars Darshan and Dhiraj at 35 and 65 DAP.

4 TABLE 4: Effect of foliar sprays of plant growth regulators on days to 50% flowering and days to flowering in gladiolus cultivars Darshan and Dhiraj. TABLE 3: Effect of foliar sprays of plant growth regulators on leaf area (cm2) in gladiolus cultivars Darshan and Dhiraj at 35 and 65 DAP. Vol. 47, No. 3,

5 196 INDIAN JOURNAL OF AGRICULTURAL RESEARCH area significantly over TIBA and found to be the next best treatment to GA ppm and BR 10 ppm. The increase in plant height may be ascribed to the stimulation of cell division and cell enlargement with the application of CPPU as explained by Yu et al. (2001). Increased spear length in asparagus with foliar spray of CPPU was reported by Ku et al. (2008). The reduction in vegetative growth due to TIBA treatments might be due its anti- auxin character by preventing the transport of naturally produced auxins thereby reducing cell elongation. Darginaviciene and Maksimov (2001) reported that TIBA inhibited both invivo and in vitro, the processes of specific IAA binding and physiological activity of the resulting IAA-protien complexes of spring wheat coleoptile cell plasmalemma. These findings are in line with the reports of Devi et al. (2007) in gladiolus. Cv. Darshan was significantly superior over the cv. Dhiraj in respect of days to 50% flowering, days to flowering, per cent plants flowered, spike length, number of florets per spike, inter floret length and spike longevity (Tables 4, 5, 6, 7 and 8) in both the years. Varietal variation in respect of flowering performance was reported by several workers. Growth regulating chemicals significantly influenced the days to 50% flowering, days to flowering, spike length, spike weight, number of florets per spi ke and spi ke longevity. The treatments GA ppm and BR 10 ppm which recorded higher leaf area during the active growth stage flowered earlier in the two years of study. Treatment with TIBA at 50 and 100 ppm and control which showed minimum leaf area at 65 DAP delayed flowering significantly. This suggests that certai n leaf area threshold constant is required as an inductive factor for flowering in gladi olus. This vi ew gets support from the observations of Ravidas et al. (1992) who observed delay in flowering with TIBA in the cv. Friendship. Timing the flower production is highly profitable in commercial flower crops than in any other crop as they are highly perishable and their demand and supply fluctuates heavily unlike other horticultural commodities. By adopti ng appropriate cultural practices for meeting the foliage needs, it is possible to induce early floral initiation and flowering in gladiolus. TABLE 5: Effect of foliar sprays of plant growth regulators on per cent plants flowered and number of spikes per plant in gladiolus cultivars Darshan and Dhiraj.

6 Vol. 47, No. 3, 2013 The interaction effect of cultivar and growth regulator treatments was significant on days to 50% flowering in both the years. Minimum number of days to 50% flowering was recorded in the cv. Darshan in combination with GA ppm and was found comparable with BR 10 ppm and CPPU 5 ppm. Maximum number of days to 50% flowering was observed in the cv. Dhiraj with TIBA 100 ppm and TIBA 50 ppm. GA ppm followed by BR 10 ppm significantly increased mean spike length, number of florets per spike, spike weight and spike longevity in both the years. These treatments were consistent and equally effective in increasing the leaf area almost during the entire crop growth period. The increase in leaf area thereby increased assimilate synthesis might have contributed to increase in spike length and weight by these treatments. GA 3 treatment resulted in maximum spike length and weight, number of florets per spike and spike field life. The interaction effect of cultivar and growth regulator treatments was significant on spike length in both the years. Maximum spike length was recorded in the cv. Darshan with GA ppm, while minimum spike length was observed in the cv. Dhiraj with TIBA 100 ppm and TIBA 50 ppm. The increased spike length with GA 3 might be due to rapid internodal elongation as a result of increased cell division and cell elongation in the intercalary meristem (Sauter and Kende, 1992). As GA 3 promotes vegetative growth and increases the photosynthetic and metabolic activities causing more transport and utilization of photosynthetic products might have resulted in increased spike length. Similar results were also reported by Pranav Rana et al (2005) and Vijai Kumar and Umrao (2007). Number of florets per spike and field life were maximum with GA ppm treatment followed by BR 10 ppm whereas lowest values were recorded in TIBA 100 ppm. Increase in number of florets per spike with GA 3 treatment has also been reported by Tawar et al. (2003), Pranav Rana et al (2005) and Vijai Kumar and Umrao (2007). The positive effect of GA 3 in increasing field life of gladiolus spikes was reported by Gaur et al. (2003). Reduced number of florets with TIBA might be due to reduced number of nodes associated with inhibition of auxin induced cell elongation which resulted in reduced plant height and spike length and there by minimum number of florets and reduced field life. BR 10 ppm was found TABLE 6: Effect of foliar sprays of plant growth regulators on spike length and number of florets per spike in gladiolus cultivars Darshan and Dhiraj. 197

7 TABLE 8: Effect of foliar sprays of plant growth regulators on days to wilting and spike longevity in gladiolus cultivars Darshan and Dhiraj. TABLE 7: Effect of foliar sprays of plant growth regulators on spike weight and inter floret length in gladiolus cultivars Darshan and Dhiraj 198 INDIAN JOURNAL OF AGRICULTURAL RESEARCH

8 to be the next best treatment to GA ppm in improving the floral attributes viz., spike length and weight, number of florets per spike and spike field life. Similar improvement in flowering performance Vol. 47, No. 3, of several cultivars of vegetables, including lettuce, radish, pepper and bush beans was reported by Meudt et al. (1984). Increased flowering with BR was reported by Alvarez et al. (2005) in rose. REFERENCES Alvarez R., Farias., Y and Angarita., M (2005) Effect of application of brassinosteroid (Biobras-16) on the growth and number of buds of Madame Delbard and Lidia roses. Proc. Inter. Soc. Tropical Hort., 48 : Braun., P and Wild., A (1984) The influence of brassinosteroids on growth and parameters of photosynthesis of wheat and mustard plants. J. Plant Physiol., 116 : Darginaviciene., J and Maksimov., G (2001) The role of basipetal IAA transport in the hormonal regulation of plant cell growth. Biologija, 2 : Devi., D.U, Sekhar., R.C and Babu., J.D (2007) Effect of growth regulators on flowering and corm production in gladiolus cv. Jacksonville Gold. J. Res., ANGRAU, 35 (1): Gaur., G. S, Chaudhury., T. C and Trivedi., J. D (2003) Effect of GA 3 and IAA on growth, flowering and corm production in gladiolus cv. Eurovision. Farm Sci. J., 12 (1): 1-3. Gregory., L.E (1981) Acceleration of plant growth through seed treatment with brassins. American Journal of Botany, 68 : Huang., X.X, LiFeng Zhou., Yan Hong Mao., Wei Hua Shi Kai., Wu Jian Xiang., Asami., T, Chen., Z. X and Yu Jing Quan (2009) Brassinosteroids promote photosynthesis and growth by enhancing activation of Rubisco and expression of photosynthetic genes in Cucumis sativus. Planta, 230 (6) : Ku., Y. G, Woolley., D. J and Nichols., M. A (2008) Effect of CPPU treatment on fern number, bud number, and photosynthetic rate of asparagus. Acta Horticulturae, 776 : Mandava., N. B and Thompson., M. J (1983) Chemistry and functions of brassinolide. In. Proceedings of isopentenoid symposium. [W. D. Nes, G. Fuller and L. S. Tsai (eds.)]. Dekker New York : pp Meudt., W. J, Thompson., M.J, Mandava., N. B and Worley., J. F (1984) Methods for promoting plant growth. Canadian Patent No Assigned to USA, p. 11 Pranav Rana., Jitendra Kumar and Mukesh Kumar (2005) Response of GA 3, plant spacing and planting depth on growth, flowering and corm production in gladiolus. Journal of Ornamental Horticulture (New Series,) 8 (1): Rajiv Kumar., Dubey., R.K and Misra., R.L (2002) Effect of GA 3 on growth, flowering and corm production of gladiolus. In: Floriculture Research Trend in India, Misra R L and Sanyat Misra (eds.). Indian Society of Ornamental Horticulture, IARI, New Delhi p Ravidas., L, Rajeevan., P.K and Valasala Kumari (19920 Effect of foliar application of growth regulators on the growth, flowering and corm yield of gladiolus cv. Freiendship. South Indian Horticulture, 40 (6) : Sauter and Kende., H (1992) Gibberellin induced growth and regulation of the cell division cycle in deep water rice. Planta, 188 : Singh., M.K, Parmar., A.S and Rathore., S. V. S (2002) Corm production in gladiolus as affected by size of cormels and GA 3 application. In: Floriculture Research Trend in India. Misra R L and Sanyat Misara (eds.). Proceedings of the National Symposium on Indian Floriculture in the New Millenium held during th February, 2002 at Bangalore pp Tawar., R.V, Sable., A.S and Giri., M. D (2003) Effect of growth regulators on growth and flowering of gladiolus cv. Jester. Annals of Plant Physiology, 17 (2) : Yu., J. Q, Li., Y, Qian., Y. R and Zhu., Z. J (2001) Cell division and cell enlargement in fruit of Lagenaria leucantha as influenced by pollination and plant growth substances. Plant Growth Regulation, 33 (2) : Vardhini., B.V and Rao., S. S R (2004) Influence of brassinosteroids on growth, yield, metabolite content and enzyme activities of tomato (Lycopersicon esculentum Mill.). Proc. Nation. Acad. Scie., India. Sec. B Biol. Sci. 74 (3/ 4) : Vijai Kumar and Umrao., V (2007) Effect of gibberellic acid on gladiolus. South Indian Horticulture, 55 (1-6) :