Foliar Application of NPK Improves Growth, Yield and Fiber Morphological Properties of Some Kenaf Varieties

Different concentrations of NPK fertilizer as a main factor with humic acid as a basal applied to enhance growth, fiber yield and bast morphological properties of three kenaf varieties. The research was done at Grdarasha Field/ Erbil, Kurdistan in summer season 2021. Results showed the significance differences among all growth, quantity and quality properties except of few situations. The highest plant height was noted from FH952 (V1), while the biggest stem diameter was by 4202 (V3), and the highest value of the leaf number was by 4383 (V2), which were (3.70 m, 23.77 mm and 214.67 leaf/plant), respectively. Foliar application of NPK caused to increase fresh and dry matter of total stem, bast and core fiber yields when 2000 mg L-1 applied to plants. Interaction between factors was also significantly affected all studied parameters. The biggest total fresh and dry stalk yield were noted of FH952 var. when 2000 mg L-1 NPK was added (V1NPK1), which were by (284.93 and 72.80 t/ha), respectively. While, the longest single fiber length was recorded in the situation of (V3NPK2), 4202 var. with 4000 mg L-1 NPK by almost (6 mm). Despite that, other bast fiber morphology properties changed dramatically in the other states of interaction between factors. Both concentrations of foliar application of NPK 2000 and 4000 mg L-1 were suggested to use as a nutrient supplement to the kenaf plants, since it caused to improve not just growth parameters but also quantity and quality properties of the stalk and fiber yields.