INFLUENCE OF HUMIC ACID AND MINERAL NUTRITION ON THE GROWTH, YIELD OF FLOWERS AND THE CHEMICAL CONSTITUENTS OF ROSA HYBRIDA, L.

Abstract

The present study was designed to investigate the influence of humic acid (HA) as an organic nutrition and mineral NPK and their combined effects on growth, qualitative and quantitative characteristics and the chemical constituents of Rosa hybrida, L. cv. Santrix plants. Four different doses of humic acid (HA) fertilizer at levels of 0.0, 2.0, 4.0 and 6.0 g/plant and four concentrations of NPK fertilizer at 0.0, 0.5, 1.0 and 1.5% were applied. There was a significant effect of the interaction among the treatments of humic acid (HA) and NPK fertilizers. Using humic acid (HA) at a high level of 6.0 g/plant combined with 1.0% NPK mineral fertilizer as foliar application gave a good impact on growth and flower parameters such as the number of flowers/plant, flower stem length, flower length, stem diameter and flower dry weight. The maximum significant increases in chlorophylls (a+b), carbohydrates leaves and nitrogen, phosphorus and potassium contents were obtained by using the highest rate of humic acid (6.0 g/plant) with the mineral fertilizer at 1.0 or 1.5% NPK, compared to the untreated plants.

Keywords

• rosa hybrida l
• shrubs
• cut flowers
• humic acid
• organic fertilization
• mineral fertilization
• mineral content