Effect of pinching, salicylic acid and GA3 on growth and flowering attributes in Chrysanthemum

Introduction

Annual chrysanthemum (Chrysanthemum coronarium) is popular for its diversity in size, shape and colour of blooms. It is an important flower crop grown in India for its loose flowers. Farmers are growing this flower crop because they are short-lived and yield marketable, attractive and long-lasting flowers. Farmers are looking forward for enhancement of production of its flowers per unit area. Agricultural techniques like pinching and application of growth-promoting chemicals may play pivotal role to increase the production. Pinching entails the removal of the terminal portion of shoots, which aids emergence of quality blooms on lateral branches (Singh, 2006) [1] . GA 3 trigger transitions from meristems to shoot growth, juvenile to flowering (Pradeepkumar, 2019). Salicylic acid is a plant phenolic and signalling molecule, now recognised as a phytohormone (Raskin, 1992) [2] . It takes part in numerous physiological functions of plants like photosynthesis, respiration, transpiration, nutrient uptake, senescence, inducing disease resistance, etc. (Clarke et al., 2004 and Wang et al., 2018) [3] . Hence, in present investigation pinching operation was followed along with foliar application of GA 3 and salicylic acid to find out their response on growth and flowering attributes in annual chrysanthemum.

Materials and Methods

An experiment was carried out to study the effect pinching, salicylic acid (SA) and gibberelic acid (GA 3 ) on growth and flowering characters in chrysanthemum. The experiment was conducted at Horticulture Research Farm, Department of Horticulture, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh during 2021-2022. Two levels of pinching (no pinching, single pinching at 30 DAT), three levels of GA 3 (100 ppm, 200 ppm and 300 ppm) and three levels of SA (100 ppm, 150 ppm, 200 ppm) along with control (distilled water) were taken in this investigation. There were fourteen treatment combinations. The experiment was laid out in a Randomized Block design with three replications. Seed sowing was done in the last week of November and one month old seedlings were transplanted at 60 cm row to row and 50 cm plant to plant distance. A single foliar spray of GA 3 and SA was applied 21 days after transplanting. Uniform cultural practices were followed for all the treatments. The data on various growth and flowering attributes were subjected to statistical analysis by using factorial experiment for analysis of variance (ANOVA).

Results and Discussion

Effect of pinching on growth attributes

All the growth parameters were significantly influenced due to various level of pinching except fresh leaf biomass (Table 1). Maximum no. of secondary branches/plant (166.88), no. of leaves/plant (1649.94), leaf area (9.06 cm 2 ) and dry weight of leaf (0.42 g) was observed with pinching, whereas maximum plant height at 60 DAT (49.16 cm) and at 90 DAT (120.07 cm) was found with no pinching. When pinching is done, it removes the apical bud, lowering the concentration of IAA. This encourages the lateral buds and promotes branching by overcoming apical dominance. Similar results were also reported by Meena et al. (2015) [4] , Singh et al. (2015) [5] in marigold.

Effect of GA 3 and SA on growth attributes

The effect of GA 3 and SA on growth parameters in chrysanthemum was found to be significant (Table 1). Among different levels of growth chemicals maximum no. of leaves/plant (1732.67) and plant height at 60 DAT (53.10 cm) and at 90 DAT (135.07 cm) was found with GA 3 300 ppm. Similarly, maximum fresh leaf biomass (474.06 g) was found with GA 3 300 ppm which was found at par with SA 150 ppm (472.97 g) followed by SA 100 ppm (450.78 g). Gibberellins promote growth by affecting either cell expansion or cell division. The similar results were quoted by Pushkar et al. (2012) [6] in marigold, Singh et al. (2018) [7] in lily and Singh et al. (2019) [8] in rose. Significantly, maximum no. of secondary branches/plant (180.30) was found with SA 100 ppm which was at par with SA 150 ppm (170.80). Maximum leaf area (10.32 cm 2 ) was observed with SA 200 ppm which was at par with SA 150 ppm (9.51 cm 2 ) followed by GA 3 300 ppm (8.29 cm 2 ) and dry weight of leaf (0.53 g) was observed with SA 150 ppm. The application of SA was attributed to the increase of photosynthetic tissues. Increase in leaf area is due to a positive correlation between photosynthesis and leaf area. Similar findings were reported by Pacheco et al. (2013) [9] in pot marigold.

Interaction effect

The data revealed from Table 1 showed the significant effect on all growth attributes except leaf area and plant height at 60 DAT due to interaction of different levels of pinching, GA 3 and SA. Significantly maximum no. of secondary branches/plant (206.60) was found with pinching × SA 100 ppm which was found to be at par with pinching × SA 150 ppm (205.00) similarly fresh leaf biomass (616.48 g) were found with pinching × SA 100 ppm which was at par with pinching × GA 3 300 ppm (574.61 g) followed by no pinching × SA 150 ppm (555.43 g). Similarly, maximum no. of leaves/plant (1989.00) was found with interaction of pinching and GA 3 300 ppm and dry weight of leaf (0.67 g) were observed with pinching × SA 150 ppm. Whereas maximum plant height at 90 DAT (141.17 cm) was observed with no pinching × GA 3 300 ppm. The supply of more nutrients by application of GA 3 and SA were effectively utilised by pinched plants, which might have played some role in augmenting more no. of secondary branches, no. of leaves, fresh leaf biomass and plant height. Present study is in line with the findings of Sharma et al. (2016) [10] in chrysanthemum and Chauhan et al. (2005) [11] in marigold.

Effect of pinching on flowering attributes

Various flowering parameters were significantly influenced by pinching except flower diameter, fresh and dry weight of flower ( [12] , Singh et al. (2017a) [13] in marigold and Salve et al. (2017) [14] in chrysanthemum.

Effect of GA 3 and SA on flowering attributes

Data recorded on flowering characters were statistically significant for various levels of growth promoting hormones GA 3 and SA except for dry weight of flower (Table 2 andTable 3). Earliest bud initiation (47.07 days) and flowering (76.04 days) were recorded for application of GA 3 200 ppm. Significantly maximum fresh weight of flower (1.57 g) was recorded with GA 3 200 ppm. Likewise, significantly maximum no. of flower/plant (285.13) and flowering duration (46.45 days) was found with GA 3 100 ppm which was at par with GA 3 200 ppm (275.30 and 45.58 days), respectively. Flowering attributes were noticed to be better with GA 3 . This might be due to increase in cell elongation and rapid assimilation of photosynthetic metabolites, which probably influenced floral morphogenesis. Present data on flowering characters are in line with Vijayakumar et al. (2017) [15] in China aster, Yadav et al. (2015) [16] in marigold, Dorajeerao et al. (2012) [17] in chrysanthemum and Singh et al., (2004) [18] in pot marigold. Maximum diameter of bud (17.96 mm) and maximum peduncle length (17.86 cm) were recorded from SA 100 ppm whereas, minimum values of both bud diameter (16.42 mm) and peduncle length (14.57 cm) were observed for control. Flower longevity is a desired character for chrysanthemum which was highest (9.39 days) with SA 150 ppm and was at par with GA 3 100 ppm (9.34 days). Maximum diameter of flower (6.99 cm) was recorded with SA 150 ppm which was at par with GA 3 200 ppm (6.98 cm) followed by GA 3 100 ppm (6.86 cm). SA exerts stimulatory effects on various physiological processes related to plant growth and development. These results are in close conformity with the results of Kumar et al. (2019) [19] .

Interaction effect

Interaction effect of pinching and growth promoting hormones like GA 3 and SA on flowering attributes of chrysanthemum (Table 2 and Table 3) were found statistically significant for most of characters except bud diameter, flower longevity, fresh and dry weight of flower and flowering duration. Days to bud initiation and flowering determine the availability of flower in a season. Earliest bud initiation (42.94 days) was observed with no pinching × GA 3 100 ppm.

Similarly earliest days to flowering (70.39) was found with no pinching × GA 3 300 ppm. Maximum peduncle length (19.57 cm) was recorded with interaction of pinching × SA 100 ppm. Likewise, maximum no. of flower/plant was (294.60) was obtained with pinching × GA 3 200 ppm which was at par with no pinching × GA 3 100 ppm (291.87). Significantly maximum diameter (7.09 cm) of flower was observed with interaction of pinching × SA 100 ppm which was at par with no pinching × GA 3 100 ppm (7.06 cm). Plant growth and flowering were significantly influenced with growth promoting chemicals has been observed by Singh (1999) [20] . This result is in agreement with finding of Singh et al. (2017) [21] , Singh et al. (2018a) [22] and Sarkar et al. (2018) [23] in African marigold.

Conclusion

The present investigation demonstrated that pinching, gibberellic acid (GA 3 ) and salicylic acid (SA), individually as well as in combination, significantly influenced the growth and flowering performance of annual chrysanthemum. Pinching at 30 days after transplanting enhanced vegetative growth by increasing the number of secondary branches, leaves, leaf area and leaf dry weight, and also improved important flowering attributes such as bud diameter, peduncle length, flower longevity and number of flowers per plant. In contrast, plants without pinching exhibited earlier bud initiation and flowering and a longer flowering duration. Among the growth regulators, GA 3 300 ppm was most effective for plant height, number of leaves and fresh leaf biomass, whereas GA 3 100 ppm produced the maximum number of flowers per plant and flowering duration. GA 3 200 ppm promoted early bud initiation and flowering and resulted in the high est fresh flower weight. Salicylic acid at 100 ppm was effective in enhancing secondary branching, bud diameter and peduncle length, while SA 150 ppm improved leaf dry weight, flower longevity and flower diameter. The interaction between pinching and growth regulators further improved several growth and flowering attributes, with pinching × SA 100 ppm producing maximum secondary branches and fresh leaf biomass, pinching × GA 3 300 ppm producing the maximum number of leaves, and pinching × GA 3 200 ppm producing the highest number of flowers per plant. Thus, the study confirms that appropriate integration of pinching with GA 3 and SA applications can effectively modify plant architecture and improve important flowering and quality attributes of annual chrysanthemum.

References

1. Singh AK. Flower Crops: Cultivation and Management. New Delhi: New India Publishing Agency; 2006. p. 247.
2. Raskin I. Salicylate, a new plant hormone. Plant Physiology. 1992;99(3):799-803.
3. Clarke SM, Mur LA, Wood JE, Scott IM. Salicylic acid dependent signaling promotes basal thermotolerance but is not essential for acquired thermotolerance in Arabidopsis thaliana. Plant Journal. 2004;38(3):432-447.
4. Meena Y, Sirohi HS, Tomar SB, Kumar S. Effect of planting time, spacing and pinching on growth and seed yield of African marigold cv. Pusa Narangi Gainda. Indian J Agri. Sci. 2015;85(6):797-801.
5. Singh AK, Singh SV, Sisodia A, Asmita, Hembrom R. Effect of pinching and nitrogen on growth, flowering and seed yield in African marigold cv. Pusa Narangi Gainda. Environment and Ecology. 2015;33(4B):1876-1879.
6. Pushkar NC, Singh AK. Effect of pinching and growth retardants on flowering and yield of African marigold (Tagetes erecta L.) cv. Pusa Narangi Gainda. International J. Hort. 2012;2(1):1-4.
7. Singh AK, Kapri M, Sisodia A, Padhi M. Effect of GA3 and BA (Benzyladenine) on growth and bulb production in lily (Lilium longiflorum). Int. J Curr. Microbio. App. Sci. 2018;7(6):12361240.
8. Singh AK, Kumar P, Sisodia A, Padhi M. Effect of GA3 and salicylic acid on growth and flowering in rose grown under protected condition. Journal of Pharmacognosy and Phytochemistry. 2019;8(5):462-465.
9. Pacheco AC, da Silva Cabral C, da Silva Fermino ES, Aleman CC. Salicylic acid-induced changes to growth, flowering and flavonoids production in marigold plants. Journal of Medicinal Plants Research. 2013;7(42):3158-3163.
10. Sharma G, Patanwar M, Mishra P, Shukla N. Effect of plant growth regulators and pinching on garland chrysanthemum (Dendranthema grandiflora Tzvelev). International Journal of Bio-resource and Stress Management. 2016;7(4):766-769.
11. Chauhan S, Singh CN, Singh AK. Effect of vermicompost and pinching on growth and flowering in marigold cv. Pusa Narangi Gainda. Progressive Horticulture. 2005;37(2):419-422.
12. Singh AK, Kumar P, Kumar A, Sisodia A. Effect of pinching, urea and GA3 on growth, flowering and seed attributes in African marigold (Tagetes erecta L.). Journal of Ornamental Horticulture. 2014;17(1&2):38-42.
13. Salve DM, Panchbhai DM, Badge S, Satar V. Response of pinching on flowering and quality parameters of Chrysanthemum. Plant Archives. 2017;17(1):436-38.
14. Vijayakumar S, Rajadurai KR, Pandiyaraj P. Effect of plant growth regulators on flower quality, yield and postharvest shelf life of China aster (Callistephus chinensis L. nees.) cv. Local. Int. J. Agri. Sci. 2017;7(2):297-304.
15. Yadav KS, Singh AK, Sisodia A. Effect of growth promoting chemicals on growth, flowering and seeds attributes in marigold. Annals of Plant and Soil Research. 2015;17(3):253-256.
16. Dorajeerao AV D, Mokashi AN. Yield and quality parameters of garland chrysanthemum (Chrysanthemum coronarium L.) as influenced by growth regulators/chemicals. Indian Journal of Plant Sciences. 2012;1(1):16-21.
17. Singh AK, Sharma G. Effect of growth regulating chemicals on growth and seed attributes in Calendula officinalis. Progressive Horticulture. 2004;36(2):266-268.
18. Kumar P, Sisodia A, Padhi M, Barman K, Singh AK. Plant growth and flowering in rose as influenced by application of calcium sulphate and salicylic acid. International J. Chemical Studies. 2019;7(4):3090-3093.
19. Singh AK. Response of tuberose growth, flowering and bulb production to plant bioregulators spraying. Prog. Hort. 1999;31(3):181-183.
20. Singh AK, Kumar P, Sisodia A, Pal AK, Singh HV, Padhi M. Effect of pinching, urea and GA3 on growth, flowering and seed attributes in African marigold (Tagetes erecta L.). Journal of Ornamental Horticulture. 2017;20(1&2):34-39.
21. Sarkar D, Saud BK, Mahanta P, Kalita P, Neog B, Talukdar MC. Response of pinching and gibberellic acid on growth and physiological characteristics of African marigold. Int. J. Curr. Microbiol. App. Sci. 2018;7(3):1666-1672.
22. Pradeepkumar CM, Chandrashekar SY, Kavana GB, Supriya BV. A review on role and use of gibberellic acid (GA3) in flower production. International Journal of Chemical Studies. 2020;8(1):3076-3084.
23. Wang Y, Wen T, Huang Y, Guan Y, Hu J. Salicylic acid biosynthesis inhibitors increase chilling injury to maize (Zea mays L.) seedlings. Plant Growth Regulation. 2018;86:11-21.
24. How to cite this article: Kushwaha A, Meena PK, Ratnakar TJ, Tiwari A, Meena H, Kumar R, et al. Effect of pinching, salicylic acid and GA 3 on growth and flowering attributes in Chrysanthemum. International Journal of Advanced Biochemistry Research. 2026;SP-10(9):2266-2270. doi: https://w ww.doi.org/10.33545/26174693.2026.v10.i9Sab.10162