The present experiment was carried out to define the efficiency of foliar applications
(3 times) with chelated magnesium (0, 200, 400 and 600 ppm) and iron
(0, 150, 300 and 450 ppm) for improving growth, productivity and anthocyanins
content in calyces of roselle. Results showed that calyces production and their
contents of anthocyanins were significantly increased with increasing either Mg
or Fe concentration. The combination of Mg at 600 ppm and Fe at 450 was the
most effective combined treatment in stimulating number of leaves and flowers,
flower weight per plant, calyces dry weight per plant, seed dry weight per plant,
weight of 1000 seeds and calyces content of anthocyanins. However, calyx fresh
weight attained the highest values when the medium concentration of Mg (400
ppm) combined with Fe at the highest concentration (450 ppm) was employed.