Drought affects size, nutritional quality, antioxidant activities and phenolic acids of Moringa oleifera LAM.

Abstract

To observe variation in growth performance, antioxidant activities, and nutritional quality of Moringa oleifera, we exogenously applied benzyl amino purine (BAP), ascorbic acid, and moringa leaf extract (MLE) to moringa plants at three field capacity levels, 100, 75, and 40% in a completely randomized design with three replications. We observed a decrease in growth, chlorophyll a and b, total phenolic contents, antioxidant activities, crude protein, and mineral contents of moringa leaves at 100 and 40% field capacity in comparison with 75% field capacity. BAP best improved growth performance of moringa plants, improving shoot length, root length, number of leaves and photosynthetic pigments, followed by MLE at 75% field capacity, while moringa plants showed reduced growth at 40% field capacity which was increased by BAP and MLE foliar application. Maximum contents of gallic acid, p-coumaric acid and sinapic acid were found in moringa leaves when the plants were sprayed with ascorbic acid while p-hydroxybenzoic acid and caffeic acid were maximally increased under 75% field capacity when the plants were subjected to BAP followed by MLE. The lowest and highest crude protein, calcium, potassium, magnesium, and phosphorous contents were recorded under 40 and 75% field capacity, with MLE impro-ving these contents under both conditions. It can safely be concluded that moringa plants showed retarded growth under 100 and 40% field capacity, and that the effects of deficit in nutritional quality were mitigated by applying BAP and MLE. Among these two plant growth regulators, MLE can be preferred being a natural source.