Journal of Experimental Agriculture International

The present investigation was conducted at the Agricultural Research Farm, School of Agriculture, Suresh Gyan Vihar University, Jaipur, Rajasthan, to study the effect of plant growth regulators on the growth, yield and quality of chilli (Capsicum annuum L.) during the Rabi season of 2024–25. The experiment was laid out in a randomised block design (RBD) comprising 10 treatments: T1 – control (water spray), T₂ – NAA (20 ppm), T₃ – NAA (40 ppm), T₄ – NAA (60 ppm), T₅ – GA3 (25 ppm), T₆ – GA3 (50 ppm), T₇ – GA3 (75 ppm), T₈ – 2,4-D (2.5 ppm), T₉ – 2,4-D (3.5 ppm) and T₁₀ – 2,4-D (4.5 ppm), each replicated three times. The results revealed that plant growth regulators significantly influenced the growth, yield and quality parameters of chilli. The maximum plant heights at 30, 60 and 90 days after transplanting (30.24, 42.62 and 54.38 cm, respectively) were recorded under T₆ – GA₃ (50 ppm), whereas the maximum number of branches per plant (23.18), fruit girth (0.96 cm), fruit weight (4.13 g) and fruit length (9.92 cm) were recorded under T₉ – 2,4-D (3.5 ppm). The minimum number of days to 50% flowering (50.42 days) was recorded under T3 – NAA (40 ppm). The maximum number of fruits per plant (110.34), fruit yield per plant (0.46 kg), fruit yield per plot (7.40 kg) and reported yield per hectare (128.51 t/ha) were observed under T4 – NAA (60 ppm). The highest ascorbic acid content (125.63 mg/100 g) and total soluble solids (7.70 °Brix), together with the lowest acidity (0.32%), were recorded under T₆ – GA₃ (50 ppm)_. Economically, NAA at 60 ppm recorded the highest net return (₹918,590.0/ha) and benefit–cost ratio (3.86), followed by NAA at 20 ppm. Therefore, foliar application of NAA at 60 ppm was the most effective treatment for fruit yield and reported profitability under the agro-climatic conditions of Jaipur, whereas GA3 at 50 ppm was most effective for the measured plant height and fruit-quality attributes.