The effects of various NPK levels on growth, flowering, and xanthophyll contents of African marigold (Tagetes erecta, ‘Double Eagle’) and French marigold (Tagetes patula, ‘Yellow’) were investigated. | I. AHMAD, M. ASIF, A. AMJAD, S. AHMAD Research Article Turk J Agric For 35 (2011) 641-648 © TÜBİTAK doi: Fertilization enhances growth, yield, and xanthophyll contents of marigold Iftikhar AHMAD*, Muhammad ASIF, Atyab AMJAD, Sagheer AHMAD Institute of Horticultural Sciences, University of Agriculture, Faisalabad-38040 - PAKISTAN Received: Abstract: The effects of various NPK levels on growth, flowering, and xanthophyll contents of African marigold (Tagetes erecta, ‘Double Eagle’) and French marigold (Tagetes patula, ‘Yellow’) were investigated. Plant height, number of branches plant-1, leaf area (cm2), total chlorophyll contents (mg g-1), number of flowers plant-1, flower diameter, flower quality, fresh and dry weight of a flower, total flower weight plant-1, blooming period, and days to flowering were maximum with 15:10:10 g m-2 NPK application. However, leaf nitrogen, phosphorus, and potassium contents reached the highest values with 15:20:10, 5:20:10, and 10:20:10 g m-2 NPK application, respectively. Xanthophyll contents were higher in plants fertilized with 15:20:10 g m-2 NPK application. Results suggested that NPK fertilization enhanced growth and improved yield, quality, and xanthophyll contents of marigold. Key words: Annual flowers, lutein, macronutrients, specialty cut flowers, Tagetes spp. Introduction Marigold, a member of the family Asteraceae or Compositae, is a potential commercial flower that is gaining popularity on account of its easy culture, wide adaptability, and increasing demand in the subcontinent (Asif 2008). Marigold is grown as an ornamental crop for its flowers, which are sold in the market as loose flowers in bulk, as specialty cut flowers, or for making garlands. It is also one of the most important natural sources of xanthophylls for use as natural food additive to brighten egg yolks and poultry skin (Bosma et al. 2003). Moreover, it is also being used effectively to dye fabrics commercially, where
