is experiment was carried out to study on the e ect of di erent NO 3 ¯:NH 4 + ratios on macronutrient content and growth of two cut gerbera (Gerbera jamesonii Bolus ex Hooker f.) cultivars in an open hydroponic system. e plants were nourished with di erent NO 3 ¯:NH 4 + ratios as 100:0, 80:20, 60:40, and 40:60. e application of NO 3 - and NH 4 + at ratio 40:60 caused a reduction in ower height, stem and disk diameter, number of owers, in orescence fresh and dry weight, and vase life. Results indicated that N, P and NH 4 + concentrations were enhanced in leaves of gerbera cultivars by increase of NH 4 + ratio, whereas K, Ca, Mg, and nitrate were decreased. As compared to ‘Double Dutch’, the ‘Stanza’ cultivar could uptake more of N, P, and Mg. Inversely, ‘Double Dutch’ was able to uptake more of K and Ca than ‘Stanza’. Dened optimal ratio of NO 3 ¯:NH 4 + 80:20 could be used for gerbera production in vegetative and reproductive stages.
