Two field experiments were conducted to evaluate the influence of 12 treatments represented the
combination between thee bulb sizes of Hippeastrum vittatum (small, medium, and large.) and four
concentration of BA (0, 20, 40 and 60 ppm) on the growth, flowering, bulbs productivity and chemical
composition of Hippeastrum vittatum plant. Results showed that the combined treatment between large bulb size
and BA at 60 ppm significantly gave the tallest plant, highest number of leaves / plant and the heaviest fresh and
dry weights of leave/plant, followed by the combined treatment between large bulb size and BA at 40 ppm in
the two seasons. The earliest flowering, the highest values of inflorescence length, inflorescence stem diameter,
inflorescence fresh weight and flowering percentage were recorded by the combined treatment between large
bulb size and BA at 60 ppm in the two seasons. The heaviest bulb fresh and dry weights, the highest bulbs
number/plant and the thickest bulb and bulblet were scored by the combined treatment between the large bulb
and BA at 60 ppm in the two seasons. The highest leaf N, P, K, total carbohydrates and total chlorophylls
contents were scored by the combination of large bulb size, especially, those received BA at 60 ppm in the two
seasons. Conclusively, spraying Hippeastrum vittatum plants with BA at 60 ppm induced prospective effects on
vegetative growth and flowering parameters with higher bulbs productivity.