Enhancing Tuberose (Polianthes Tuberosa L.) Growth and Productivity Through Precision Zinc Fertilization

Abstract

Objective: Tuberose (Polianthes tuberosa L.), a bulbous flowering plant, is widely cultivated for bouquets, decorative purposes and essential oil extraction. Its growth, development and flowering are significantly influenced by climatic factors, soil conditions, water availability and nutrient deficiencies. The study's objective was to investigate the effects of precision zinc fertilization on tuberose growth and productivity, with a focus on determining the optimal zinc application rates for maximizing yields and flower quality.

Materials and Methods: The research was conducted at the Floriculture Research Area, Institute of Horticultural Sciences, University of Agriculture, Faisalabad. The experimental layout followed a Randomized Complete Block Design (RCBD). Five treatments were applied, including a control (T₀), with each treatment replicated five times. Zinc spray of different concentrations was prepared along with 0.1% Calcium carbonate (CaCO₃). The treatments consisted of T₀ (control), T₁ (0.25% ZnSO₄), T₂ (0.5% ZnSO₄), T₃ (0.75% ZnSO₄) and T₄ (1% ZnSO₄). Foliar application of Zn spray was done three times, starting one month after sowing, at 30-day intervals. The experiment was conducted using a randomized complete block design. The statistical analysis of the generated data was analyzed using the software Statistix 8.1. Fisher's analysis of variance (ANOVA) technique was used and treatment means were compared using Tukey's test at a 5 percent probability level.

Results: Data on different morphological attributes were collected which indicated that treatment T4 showed maximum plant height (93.03 cm), number of leaves per plant (36.33), leaf length (45.76 cm), leaf width (1.73 cm), leaf diameter (1.38 cm²), spike length (77.83 cm), number of florets per spike (44.33), floret length (7.0 cm), floret width (3.07 cm), floret diameter (3.96 cm²), petal length (2.85 cm), petal width (2.63 cm), petal diameter (2.80 cm²), vase life of flowers (10.67 days), leaf nutrients zinc analysis (0.24 mg/g), leaf nutrients calcium analysis (2.3 mg/g), flower quality (9.20) and total leaf chlorophyll contents (72.48). Results demonstrated that foliar application of ZnSO₄, particularly at 0.75 and 1.00% concentrations, significantly enhanced both vegetative and reproductive traits in tuberose. The improvements in morphological features, nutrient uptake, chlorophyll content and post-harvest life underscore zinc’s crucial role in optimizing plant vigor and floral aesthetics.

Conclusion: The findings establish a strong dose-dependent response to zinc application, with 0.75% ZnSO₄ emerging as the optimal concentration. This study reinforces the significance of precision zinc fertilization in ornamental horticulture for enhancing productivity, quality and market value of cut flowers.