Multivariate assessment of growth dynamics and yield determinants in ‘Snow Mystique’ cauliflower under varying plant spacings in Eastern Nepal

Cauliflower (Brassica oleracea var. botrytis L.) is a major winter vegetable in Nepal, but its productivity often fluctuates due to suboptimal plant density and improper spacing management. To overcome this challenge, the present study was conducted at ILAM-9, Sera, Ilam District (26.90° N, 87.92° E; 989 m asl) from December 2023 to April 2024. The objective was to determine the optimal plant spacing for maximizing growth, yield, and curd quality of the hybrid variety ‘Snow Mystique’. The experiment followed a Randomized Complete Block Design (RCBD) with four spacing treatments: 45 × 45 cm, 50 × 50 cm, 45 × 50 cm, and 60 × 60 cm, replicated five times. Growth parameters (plant height, canopy cover, and leaf number) and reproductive attributes (curd initiation, maturity, size, and yield) were recorded at successive growth intervals. Results revealed that spacing significantly influenced both vegetative and reproductive traits. Moderate spacing (50 × 50 cm) consistently produced the tallest plants, broader canopy cover, greater leaf numbers, earlier curd initiation, and the highest yield (≈47–48 t ha⁻¹). Wider spacing (60 × 60 cm) enhanced individual plant growth but reduced total yield due to lower plant population, while closer spacing (45 × 50 cm) induced competition stress. Multivariate and correlation analyses identified plant height, leaf number, and curd size as key yield determinants. The study concludes that a spacing of 50 × 50 cm is optimal for achieving balanced growth and maximum productivity of Snow Mystique cauliflower under mid-hill agro-climatic conditions of Eastern Nepal. Future research should integrate nutrient management, mulching, and varietal interaction studies to further refine site-specific spacing recommendations.