Combined effects of NPK fertilizer with foliar application of benzyladenine or gibberellic acid on Dracaena marginata ‘Bicolor’ grown in different potting media

Abstract

A pot experiments was carried out to evaluate the influence of growing media and combined treatments of NPK with either benzyladenine or gibberellic acid on growth, chemical constituents and anatomical structure of Dracaena marginata ‘Bicolor’. The plants were grown in two growing media; peat-moss, peat-moss+ sand (1:1, v v-1), received monthly NPK fertilizers (2 and 4 g pot-1) combined with either of benzyl adenine (BA) at 100 and 150 ppm or gibberellic acid (GA3 ) at 150 and 250 ppm, while the control plants received no treatments. As general, the results indicated that, peat- moss was superior to peat-moss+ sand medium on increasing most of vegetative growth parameters in terms of plant height, number of leaves/plant, leaf area, root length, as well as fresh and dry weights of leaves, stems and roots/plant, besides some macro elements represented in N, P, K, Ca and Mg% in both leaves and stems. While plants grown in peat-moss+ sand possessed significantly higher contents of total chlorophylls, total carbohydrates, Cu, Fe, Mn, Zn and B than those grown in peat- moss alone. Plants received combined NPK with either BA or GA3 resulted in significant increases in most of morphological and chemicals content over the control plants and it was outstanding that, GA3 was more effective than BA when they were combined with NPK. It can be concluded that for the highest quality, quantity growth and economic production of Dracaena marginata ‘Bicolor’, the plants could be grown in a medium of peat-moss and supplied monthly with NPK fertilizer at 2 g plant-1 along with foliar sprayed with 250 ppm GA3.