Influence of Plant Growth Regulators on Growth and Capsule Traits of Small Cardamom (Elettaria cardamomum L. Maton)

Abstract

Small cardamom (Elettaria cardamomum L.) is a high-value spice crop whose productivity is often limited by poor fruit set and capsule development. Plant growth regulators have shown potential in improving growth and reproductive efficiency in horticultural crops, but their standardized use in cardamom remains limited. A field experiment was conducted at the Cardamom Research Station, Pampadumpara, Kerala during 2024–2025 to evaluate the influence of plant growth regulators (PGRs) on growth and capsule traits of small cardamom (Elettaria cardamomum L. Maton). The experiment was laid out in a randomized block design with 14 treatments and three replications. Treatments comprised gibberellic acid (GA₃), naphthalene acetic acid (NAA), benzyl adenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D) at different concentrations along with controls. Growth parameters such as panicle length and internodal length were significantly influenced, with GA₃ @ 250 ppm recording superior values. Capsule traits including capsule length, width and number of seeds per capsule were also significantly affected. NAA @ 60 ppm recorded higher seed number and capsule width, while GA₃ @ 250 ppm recorded maximum capsule length. Parameters such as percentage of bold capsules were not significantly influenced. However, capsule weight and size-related attributes showed variation among treatments, indicating differences in capsule development and filling. The study indicates that plant growth regulators influence growth and capsule traits in small cardamom, with responses varying based on the type and concentration of the regulator, and highlights their potential role in improving capsule development and yield attributes.