EFFECT OF PLANT GROWTH REGULATORS AND LIQUID NANO-UREA ON VEGETATIVE GROWTH, FRUIT SET AND PHYSICAL QUALITY PARAMETER OF DRAGON FRUIT (HYLOCEREUS COSTARICENSIS)

Abstract

Dragon fruit (Hylocereus costaricensis) is an emerging fruit crop in subtropical regions, where optimization of vegetative growth and fruit development is essential for improving productivity. A two-year field experiment was conducted during 2024-25 and 2025-26 under subtropical conditions of Western Uttar Pradesh, India, to evaluate the effect of plant growth regulators and liquid nano-urea on growth and fruit attributes of dragon fruit. Ten treatments comprising brassinosteroid, jasmonic acid and liquid nano-urea in combination with the recommended dose of fertilizers (RDF) were evaluated in a randomized block design with three replications. The pooled results showed that T₂ (brassinosteroid 5 ppm + RDF) performed consistently better for most of the growth and fruit attributes. It recorded the highest plant length at 90 DAI (187.86 cm), number of segments (13.67 plant⁻¹) and number of areoles (300.67 plant⁻¹), while the maximum number of primary branches was recorded with T₁ (35.00 plant⁻¹). T₂ also produced the highest fruit length (12.25 cm), fruit volume (318.06 cc), fruit diameter (8.698 cm) and pulp weight (219.17 g). Fruit set was highest under T₂ and T₉ (98.17% each), compared with 94.67% in the control (T₀). Among the nano-urea treatments, T₈ (15 ml/4.5 L + RDF) showed comparatively better performance for growth and fruit attributes. Overall, the application of brassinosteroid at 5 ppm along with RDF was the most effective treatment for improving vegetative growth and physical fruit attributes of dragon fruit under the subtropical conditions of Western Uttar Pradesh.