FOLIAR NPK FERTILIZATION ENHANCES GROWTH, FLOWERING, AND ORNAMENTAL PERFORMANCE OF ZINNIA ELEGANS L. UNDER SEMI-ARID CONDITIONS
Keywords:
Zinnia elegans; foliar fertilization; nitrogen; phosphorus; potassium; ornamental horticulture; flowering performance; vegetative growth; flower quality.Abstract
Zinnia elegans L. is one of the most economically important ornamental flowering species cultivated worldwide because of its attractive blooms, prolonged flowering period, and suitability for landscaping and cut-flower production. Balanced nutrient management, particularly through foliar fertilization, plays a pivotal role in improving vegetative growth and flower quality. The present study evaluated the effects of foliar application of nitrogen (N), phosphorus (P), and potassium (K) on the growth, flowering behavior, and ornamental performance of Zinnia elegans under the agro-climatic conditions of Lasbela, Pakistan. The experiment was conducted using a Completely Randomized Design (CRD) comprising four treatments, including an unfertilized control and three NPK concentrations (6, 12, and 18 g), each replicated three times. Growth and flowering parameters, including plant height, number of leaves, stem diameter, number of branches, flower diameter, flower stalk length, number of flowers per plant, fresh and dry flower weight, and days to flowering initiation, were recorded and statistically analyzed using analysis of variance (ANOVA). Foliar application of NPK significantly (P < 0.05) enhanced all measured vegetative and reproductive characteristics compared with the control treatment. Plants receiving 18 g NPK exhibited the greatest plant height, leaf production, stem diameter, flower diameter, flower weight, flower number, and branch development while producing earlier flowering than untreated plants. The findings demonstrate that balanced foliar nutrition effectively promotes plant vigor, accelerates flowering, and improves the ornamental quality of Zinnia elegans. Therefore, foliar application of 18 g NPK is recommended as an effective nutrient management strategy for maximizing the commercial production and aesthetic value of Zinnia elegans under the environmental conditions of Lasbela.
