Influence of Some Plant Growth Regulators on Quality Attributes of Pineapple (Ananas comosus L.)

Aims: A trial was conducted to investigate the influence of plant growth regulators on the growth and quality attributes of pineapple fruits. Study Design: The experiment was arranged in a randomized completed block design (RBCD) with three replications using 25 plants per replication. Place and Duration of Study: The experiment was carried out between 2020 and 2021 at the Central Horticultural Experiment Station, Aignia, Bhubaneswar, India. Methodology: The application of PGRs i.e. naphthalene acetic acid (NAA), gibberellic acid (GA), and brassinosteroid (BR) was done at the flower initiation stage. Only water application is done in case of control. Fruits were harvested at the ripe stage and an analysis of different growth and quality parameters were done. Results: The application of naphthalene acetic acid (NAA), and gibberellic acid (GA) significantly improved the yield and quality attributes of pineapple. Application of NAA 200 mgL-1 (T3) was found to be the most effective in enhancing absolute growth rate (2.65 g day-1), fruit weight (1.58 kg), and fruit/crown ratio (6.38). It was also evident that the application of NAA 200 mgL-1 improved fruit quality in terms of soluble solid contents (17.67 oBrix), soluble solid contents to acid ratio (19.49), reducing sugar (3.54%), and total sugar content (12.38%). Higher pulp content (73.89%), pulp-to-peel ratio (3.49), and juice content (54.50%) were also observed with NAA 200 mgL-1. Conclusion: NAA 200 mgL-1 significantly improved fruit growth i.e. fruit weight, fruit-to-crown ratio, and absolute growth rate. It also enhanced the quality attributes of pineapple fruits i.e. pulp content, pulp-to-peel ratio, juice content, pH, soluble solid contents, SSC to acid ratio, reducing sugar, and total sugar content.