Effect of different plant growth regulators on growth, flowering and quality of tuberose (Polianthes tuberosa L.) cv. GKTC-4 under Prayagraj agro-climatic conditions

Introduction

Tuberose (Polianthes tuberosa) is a widely cultivated ornamental and aromatic plant known for its highly fragrant flowers. This review provides a comprehensive overview of the botanical, agronomic, and commercial aspects of tuberose cultivation. Originating from Mexico, tuberose spread to various parts of the world, including Europe, Africa, and Asia, during the 16th century. Its introduction to India is believed to have been facilitated by the British. The plant is characterized by long, narrow leaves and tall flowering stalks bearing clusters of waxy white flowers with a strong fragrance. Tuberose varieties are classified based on flower type: single, semi-double, double, and variegated. Various cultivars, such as Mexican, Calcutta, and Hyderabad, have been named after their place of origin or cultivation. Tuberose is a half-hardy bulbous crop that thrives in mild climates with temperatures ranging from 20-35 °C, preferably with high humidity. It is commercially grown in several regions of India, including West Bengal, Karnataka, Andhra Pradesh, Tamil Nadu, Uttar Pradesh, and limited areas of Haryana and Punjab. The production of tuberose flowers depends on climatic conditions, soil fertility, and agronomic practices. Under optimum conditions, a single hectare of tuberose can yield about 5,00,000 flower spikes or 10.5 tonnes of loose flowers. Despite its commercial importance, tuberose faces challenges in seed setting, particularly in single-flowered cultivars. However, variegated cultivars exhibit a higher degree of seed setting. The exact reasons for poor seed setting remain unclear but may be attributed to factors such as lack of pollinizers. Tuberose flowers are not only prized for their ornamental value but also for their essential oil, which is rich in compounds such as geraniol, nerol, and eugenol. The oil is extracted using solvents like hexane and is used in perfumery and aromatherapy.

This review concludes with a discussion on the genetic and chromosomal characteristics of tuberose, highlighting its close relation to other species within the Polianthes genus. Future research directions are proposed to address the challenges in tuberose cultivation and to explore its potential applications in various industries.

Materials and Methods

A field experiment entitled "Effect of different plant growth regulators on growth, yield and quality of tuberose (Polianthes tuberosa L.) c.v. GKTC-4"" under Prayagraj agroclimatic conditions" have been describes in this chapter.

Experiment was carried out at the experimental field of the Department of Horticulture, Naini Agriculture Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, U.P to find out most suitable plant growth regulator on growth, flowering and yield of tuberose. The experiment was conducted in Randomized Block Design with 9 treatment in three replications viz. T 0: CONTROL, T 1: GA3 @100ppm, T 2: GA3@200ppm, T 3: GA3@300ppm, T 4: CCC@1000ppm, T5: CCC@1500ppm, T 6: CCC@2000ppm, T 7: TRIA@4ppm, T 8: TRIA@6ppm, T 9: TRIA@8ppm. Crop was planted with the spacing of 30 cm × 30 cm.

Results and Discussion Vegetative Parameters of Different Treatments on tuberose Variety Plant height and plant spread

The investigation conducted at the Horticulture Research Field, Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology And Sciences, Prayagraj (U.P.) from April 2023 to March 2024 revealed significant differences among tuberose varieties concerning plant height, and plant spread. Among the treatments, treatment GA3@ 300ppm recorded significantly taller (55.27 cm), which was found to be followed by with TRIA@ 4ppm (52.13 cm) whereas, shorter plants (33.27 cm) water spray. These result are in agreement to those reported by the (Dhumal et al., 2018) [9] . Among the treatments, treatment GA3@ 300ppm recorded significantly more plant spread (58.56 cm 2 ), which was found to be followed by with TRIA@ 4ppm (57.7 cm 2 ) whereas, lesser plant spread (42.8cm 2 ) was recorded in Control (water spray). Significant variation in plant spread observed the among different varities may be attributed to hereditary traits and their manifestation in a given set of environmental condutions. These result are in agreement to those reported by the (Dhumal et al., 2018) [9] .

Floral parameters of different varieties of tuberose Days to First Spike Initiation and First Flowering

The minimum Days to bud initiation was observed with T 3 -GA3 @ 300 ppm (21.33) which was at par with T 7 -TRIA @4 ppm (23.22) whereas, maximum number of days was reported in T 0 -Water spray (27.22). The minimum Days taken for first flower opening from planting was observed with T 3 -GA3 @ 300 ppm (36.66) which was at par with T 7 -TRIA @4 ppm (36.88) whereas, maximum was reported in T 0 -Water spray (48.4). Early bud initiation may be attributed to higher photosynthetic assimilation due to vigorous plant growth, a factor governed by genetic composition of different varieties and impact of the growing environment. The data for early bud initiation in conformity with the findings of (Gawai et al., 2009) [8] and (Dalvi et al., 2021) [3] .

Rachis and Spike Length

The maximum Rachis length (cm) was observed with T 3 -GA3 @ 300 ppm (44.60) which was at par T 7 -TRIA @4 ppm(41.86) whereas, minimum was reported in T 0 -Water spray (22.46). The maximum Flower spike length (cm) was observed with T 3 -GA3 @ 300 ppm (74.86) which was at par with T 7 -TRIA @4 ppm (73.40) whereas, minimum was reported in T 0 -Water spray (59.20). Rachis and spike length are genetically controlled traits and varies with genetic make-up of the varieties and the prevailing environmental conditions. Variation in rachis length in different treatment is also observed by (Amin et al., 2017) [2] and (Lakshmi et al., 2019) [1] .

Number of Florets per Spike

The maximum Number of florets was observed with T 3 -GA3 @ 300 ppm (49.73) which was at par with T 7 -TRIA @4ppm (45.86) whereas, minimum was reported in T 0 -Water spray (37.60). Number of florets are genetically herited characters. This variation in number of florets may be due to among the different treatment of PGRs and prevailing environmental conditions. Variation in number of florets among the treatments was also reported (Patil et al., 2009) [4] .

Diameter of florets

The maximum Diameter of florets (cm) was observed with T 3 -GA3 @ 300 ppm (4.51) which was at par with T 7 -TRIA@4 ppm (4.46) whereas, minimum was reported in T 0 -Water spray (4.10). Diameter of florets are genetically herited characters. This variation in diameter of florets may be due to among the different treatment of PGRs and prevailing environmental conditions. Variation in number of florets among the treatments was also reported (Patil et al., 2009) [4] .

Weight of florets

The maximum Weight of florets (g) was observed with T 3 -GA3 @ 300 ppm (2.06) which was at par with T 7 -TRIA @4ppm (1.93) whereas, minimum was reported in T 0 -Water spray (1.40). Weight of florets are genetically herited characters. This variation in weight of florets may be due to among the different treatment of PGRs and prevailing environmental conditions. Variation in number of florets among the treatments was also reported (Patil et al., 2009) [4] .

Shelf Life

The maximum Shelf life was observed with T 3 -GA3 @ 300 ppm (3.77) which was at par with T 7 -TRIA @4 ppm (3.66) whereas, minimum was reported in T 0 -Water spray (2.33). The variation in shelf life might be due to temperature that reduces the entire metabolism of the tissues, slows down the respiration and transpiration, ethylene action and retards the multiplication of bacteria and fungi. This observation is in the accountance with the (Kumar et al., 2018) [10] .

Number of spike per plant

The maximum Number of spike per plant was observed with T 3 -GA3 @ 300 ppm (3.46) which was at par with T 7 -TRIA @4 ppm (3.20) whereas, minimum was reported in T 0 -Water spray (2.46). The variation in the total number of spike per clump might be attributed to the difference. In utilization of nutrients by plants or the effect of cultural practices like hoeing and the genetic composition and environmental circumstances may also be directly connected to the variance in the number of spikes per plant. Similar finding is also observed by (Sobhana et al., 2000) [6] .

Spike per hectare of tuberose: The maximum Number of spike per hectare was observed with T 3 -GA3 @ 300 ppm (2,80,800) which was at par with T 7 -TRIA @4 ppm (2,59,200) whereas, minimum was reported in T 0 -Water spray (1,99,800). The variation in the total number of spike per hectare might be attributed to the difference in utilization of nutrients by plants or the effect of cultural practices like hoeing and the genetic composition and environmental circumstances may also be directly connected to the variance in the number of spikes per hectare (Maheshwari et al., 2018) [11] . (2,80,800). Among the different treatments, the highest gross return is 14,69,520 Rs/ha, Net return is 8,79,384 Rs/ha and benefit cost ratio is 2.49, obtained under the use of GA3 @300 ppm in the treatment T 3 . Hence, GA3 @ 300 ppm can be recommended for plant growth, yield and quality of Tuberose (Polianthes tuberosa) cv. GKTC-4.

Acknowledgement

AcknowledgementI express my gratitude to my Advisor Dr. Vijay Bahadur for constant support, guidance and valuable suggestions for improving the quality of this research work and to all the faculty members of Department of Horticulture, SHUATS, Prayagraj, Uttar Pradesh for providing all necessary facilities, their cooperation, encouragement and support. For this research, a total of nine treatment of PGRs and one tuberose variety were used. Among the three PGRs were procured from Alopibagh, Prayagraj and one variety of tuberose was procured from FFDC, Kannauj, Uttar Pradesh.

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