Abstract
The extensive use of synthetic chemical fertilizers is associated with environmental pollution
and soil degradation. In addition, the high costs of these fertilizers necessitate the search
for alternative, eco-friendly and safe natural sources of phytonutrients. The liquid extracted from
moringa (Moringa oleifera Lam.) leaves has been used in agriculture to improve the growth and
productivity of several crops. The efficacy of moringa leaf extract (MLE) is attributed to its high
content of mineral nutrients, protein, vitamins, sugars, fiber, phenolics and free proline. In addition,
MLE contains significant amounts of phytohormones, such as auxins, cytokinins and gibberellins.
Furthermore, MLE is a valuable product promoting seed germination, plant growth and deeper root
development, delaying fruit senescence and increasing the yield and quality of crops grown under
normal or stressful conditions. Here, we review the research on MLE as a biostimulant to enhance
crop growth and productivity. Moreover, we emphasize its possible introduction to smallholder
farming systems to provide phytonutrients, and we further highlight research gaps in the existing
knowledge regarding MLE application. Generally, MLE is an inexpensive, sustainable, eco-friendly
and natural biostimulant that can be used to improve the growth and productivity attributes of
various crops under non-stressful and stressful conditions.