International Journal of Plant & Soil Science

In recent years, interest in the cultivation and consumption of capsicum has significantly increased, driving research toward identifying the most favorable conditions for its growth and productivity. Biostimulants are materials or microorganisms used in agriculture to boost a plant’s nutrient uptake, enhance its tolerance to abiotic stress, and improve overall crop performance. They are broadly categorized into groups such as humic and fulvic acids, protein hydrolysates, nitrogen-based substances, seaweed extracts, plant-based compounds, chitosan and other biopolymers, inorganic materials, and beneficial microbes like fungi and bacteria. The present study was conducted to evaluate the effect of biostimulants on the yield and yield-attributing traits of capsicum. A total of twelve treatments, including an absolute control, were tested using a Randomized Block Design (RBD) with four replications. The research was carried out under polyhouse conditions at the Department of Vegetable Science, CCS Haryana Agricultural University, Hisar, during the Rabi seasons of 2022–23 and 2023–24, utilising the PSM-1 variety as the test material. The results revealed significant differences among treatments for all recorded parameters, including days to first flowering, fruit maturity, number of fruits per plant, fruit size, average fruit weight, and total yield. The treatment T₃ (RDF + Seaweed extract @ 2.5 ml/L) emerged as the most effective, recording the earliest flowering (41.75 days), highest number of fruits per plant (22.50), maximum fruit length (9.55 cm), fruit diameter (7.96 cm), average fruit weight (95.74 g), and highest total yield (399.05 q/ha). Comparatively, treatments involving 87.5% RDF alone or with biostimulants showed moderate improvements but were generally less effective than those with 100% RDF. Thus, the integrated application of biostimulants with full RDF, particularly seaweed extract, is recommended for optimizing capsicum productivity and quality in protected cultivation systems.