The potential of Moringa oleifera extract as a biostimulant in enhancing the growth, biochemical and hormonal contents in rocket (Eruca vesicaria subsp. sativa) plants

Moringa oleifera is a highly valued plant, distributed in many countries of the tropics and subtropics. It has an impressive range of medicinal uses and high nutritional value. Accordingly, rocket (Eruca vesicaria subsp. sativa) plants were foliar sprayed with the aqueous extracts of leaves and twigs of M. oleifera at rates of 1, 2 and 3%. Among these concentrations, fertilization of rocket plants with 2% leaf and 3% twig extracts potentially increased all measured growth criteria (plant height, fresh and dry herb weight), photosynthetic rates, stomatal conductance, the amounts of each of chlorophyll a and b, carotenoids, total sugars, total protein, phenols, ascorbic acid, N, P, K, Ca, Mg, Fe as well as growth promoting hormones (auxins, gibberellins and cytokinins). Besides, bio-organic manuring with both kinds of Moringa extracts at all concentrations applied negatively reduced the levels of each of lipid peroxidation and abscisic acid as well as the activities of the antioxidant enzymes (catalase, peroxidase and superoxide dismutase). Thus, it is concluded that M. oleifera leaf and twig extracts can be recommended to be used effectively by farmers as a bio-organic fertilizer for various crops due to its high productivity, high nutritive value, antioxidant effect, easy preparation, low cost and environmentally friendly nature.   Key words: Moringa oleifera, growth, gas exchange, antioxidants, metabolites, phytohormones, photosynthetic pigments.