Combined Effect of Humic Acid and NPK on Growth and Flower Development of Tulipa gesneriana in Faisalabad, Pakistan

A research trial was conducted during 2011-2012 to elucidate the effects of humic acid (HA) and NPK to determine the optimum rate against different growth and floral attributes on tulip cultivar viz. ‘Triumph’. The following five treatments T0 : (control), T1: 10 g/m2 NPK (17:17:17), T2 : HA 0.75 ml (8%) + 10 g/m2 NPK (17:17:17), T3: HA 1.00 ml (8%) + 10 g/m2 NPK (17:17:17) and T4: HA 1.25 ml (8%) + 10 g/m2 NPK (17:17:17) were applied under RCBD replicated thrice. All the vegetative and reproductive attributes were significantly influenced by the addition of humic acid and NPK and obtained results revealed that treatment T4 was the most effective one compared with the other treatments. This treatment gave the inimitable outcomes concerning earliest sprouting and flowering, plant height increment, leaf area expansion, stem diameter, leaf chlorophyll contents, stalk length, vase life, fresh and dry flower biomass. It also increased the nutrient contents comparing with the T3 and T2. In comparison, the plants grown without HA and NPK application (control) followed by a single application of NPK (T1) exhibited poor growth with reduced yield of inferior quality. The data obtained in this study conveyed that HA (1.25 ml of 8% humic acid) along with NPK application (10 g/m2 NPK) helps to improve the uniform crop stand, plant growth and flower quality of tulip.