EFFECTS OF AMMONIUM RATIO AND NUTRIENT DELIVERY INTERVAL ON ROSES GROWING IN AEROPONICS

Abstract

Roses have been grown for centuries because of their aesthetic value in landscapes, pots or vases as well as their nutritional and therapeutic significance. This has led growers to search for means of improving its production by changing the mode of cultivation and the fertilization regime. The development of a new aeroponic system is reported here. Stentings of Rosa x hybrida 'Prestige' were placed on top of separate mist chambers and nutrient solutions were sprayed on their bare roots by means of pressurized air. Aeroponically-grown roses were treated with four NH 4 + /total N ratios (0.14, 0.03, 0.02 and 0.008) of a complete nutrient solution and two spray intervals (3/15 min and 3/30 min; on/off). Subsequent growth of plants was measured by number of flowers, length and thickness of flowering stems, length and thickness of flower buds, leaf and total dry weight and total leaf number. The middle range proportions of ammonium-N in the nutrient solutions (0.03 and 0.02) improved the growth characteristics of plants including number of flowers, leaf and total dry weight, and length and thickness of flower buds. The shorter spray interval (3/15 min) resulted in roses with improved growth: length and thickness of flowering stems, length and thickness of flower buds and total leaf number were enhanced.