Development of soilless culture methods for production of moringa (Moringa oleifera Lam.) root and leaf biomass

Abstract

The soilless culture of a xerophytic, multipurpose tree used in agroforestry was demonstrated. Medical evidence for the nutritional, therapeutic, and prophylactic properties of moringa (Moringa oleifera Lam) and its numerous agricultural and industrial uses have encouraged scientists to further examine the potential of this valuable plant. Tissue culture techniques have been developed for the moringa genus to ensure the maintenance of germplasm, but poor survival of plantlets suggests that transfer to hydroponic culture rather than soil culture may be advantageous. Moringa has been identified as a plant to be analyzed using a stable isotope technique using hydroponic culture to measure vegetable specific β-carotene absorption to combat Vitamin A deficiency. Hydroponic culture will also provide access to uncontaminated root biomass. Because little information is available regarding the hydroponic culture of moringa, protocols were studied for producing leaf and root biomass. Seed obtained from Uganda and Haiti, were germinated at 25°C in rockwool cubes using a 16 h photoperiod and a photon fluence rate of 250 μmol·m-2·s-1. Germination rates of upto 65% were obtained for the dehulled seeds, but germination was low in hulled seeds. Seedlings grew extremely well in recirculating rockwool slab culture for more than three months using a nutrient solution consisting of 1.0 g·L-1 5-11-26 Hydrosol, 0.75 g·L-1 15.5-0-0 Calcium Nitrate Plus and 0.25 g·L-1 MgSO4· 7H2O and having electrical conductivity (EC) levels maintained between 2.0 and 2.3 dS·m-1. Maintaining a dry region around the base of stems was critical. Seedlings grown at pH 5.5, 6.0, 6.5, 7.0 and 7.5 demonstrated optimum growth between pH 5.5-6.0. Moringa plants grown aeroponically using a commercially available, recirculating, Aeroflo® system, resulted in robust plants with well developed, fibrous, root biomass. This study demonstrated that moringa can be successfully grown using hydroponics.