Influence of foliar applied nitrogen, phosphorus and potassium on the vegetative and reproductive attributes of Roselle (Hibiscus sabdariffa)

An experiment was conducted to study the influence of foliar application of nitrogen, phosphorus and potash (NPK) on the vegetative and reproductive attributes of Roselle. The experiment was designed using Randomized Complete Block Design (RCBD) with one factor i.e., NPK treatments (0, 3, 4, 5, 6 g l-1). Treatments were repeated four times. The experiment was carried out in Ornamental Horticulture Nursery, Department of Horticulture, The University of Agriculture, Peshawar during the year 2020. Data were recorded on plant height (cm), stem diameter(mm), number of branches plant-1, number of leafs plant-1, leaf area(cm2), days to first flowering, days to last flowering, number of calyces plant-l, calyx diameter, calyces fresh weight plant-l, pod size, number of seeds pod-l .  Foliar application of NPK had significant effect on most of the studied attributes. Maximum plant height (104.75 cm), stem diameter (2.23 mm), number of branches plant-1 (13.5), number of leaves plant-1 (301), and leaf area (118.25cm2), minimum days to first flowering (106.50), maximum days to last flowering (128), calyx diameter (27.275 mm), calyces fresh weight plant-1(219.88 g), pod size(21.532 mm) and number of seeds pod-1 (25.68) were recorded in plants sprayed with  NPK @  6g L-1.  Minimum plant height (67.50 cm), stem diameter (0.7775 mm), number of branches (4.000), number of leaves (58.50), and leaf area (113.00cm2), maximum days to first flowering (109.00), minimum days to last flowering (114.75), calyx diameter (23.835mm), calyces fresh weight plant-1 (89.84 g), pod size (19.617mm) and number of seeds (21.688) were recorded in control plants (Sprayed with distilled water). It is concluded that plants treated with foliar applied NPK at 6g L-1  improved most of the vegetative and reproductive variables of Roselle and hence could be recommended for better growth and production of Roselle under the agro-climatic conditions of  Peshawar.