Chitosan-induced Enhancement of Plant Growth and Yield in Bush Pepper

Chitosan is a potential biostimulant for enhancing plant growth and productivity. The present study evaluated the effect of different concentrations and methods of chitosan application on growth and yield attributes of bush pepper (Piper nigrum L.), variety Panniyur 1. The experiment was laid out in a completely randomised design with seven treatments. Chitosan was applied as foliar spray (1.0, 1.5 and 2.0 g L⁻¹) and soil drench (2.0, 3.0 and 4.0 g L⁻¹) at bimonthly intervals. The untreated plants served as control. Chitosan application significantly influenced plant height, secondary branching, leaf production, leaf area, spike length and fresh berry weight. Foliar application at 1.5 g L⁻¹ resulted in the highest plant height at 6 and 12 months after initiation of chitosan application (56.97 and 64.40 cm, respectively). Soil drenching at 2.0 g L⁻¹ recorded the highest number of leaves (40.93) and leaf area (3301.30 cm²) at 12 months after initiation of chitosan application. Soil drenching at 3.0 g L-¹ produced the highest spike length (7.83 cm). Soil drenching with chitosan at 2.0, 3.0 and 4.0 g L⁻¹ and foliar spraying at 1.5 g L⁻¹ resulted in significantly higher fresh berry weights, with the highest value (63.47 g plant⁻¹) recorded following soil drenching at 2.0 g L⁻¹. Overall, chitosan application improved vegetative growth and yield attributes in bush pepper.