Biostimulants as Innovative Tools to Boost Date Palm (Phoenix dactylifera L.) Performance under Drought, Salinity, and Heavy Metal(Oid)s’ Stresses: A Concise Review

Abstract

Date palm (Phoenix dactylifera L.) is constantly subjected to abiotic stresses. Hence, the application of biostimulants, such as the arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR), and organic amendments hold tremendous potential to significantly improve the growth and yield of date palm. The strengthening of biostimulants’ main common modes of action is exerted through five main functions: biostimulation (essentially), biofertilization, bioprotection, biological control, and the role of bio-effector. Moreover, synergistic and complementary effects manifest through biochemical and nutritional benefits, in addition to molecular modulation. In this regard, the present concise review focuses on highlighting the beneficial impact of AMF and PGPR, as well as the organic amendments, in boosting the health status and productivity of date palm plants subjected to abiotic stresses. Furthermore, mechanisms reinforcing date palm plants’ resilience to abiotic stresses, powered by biostimulants, are particularly emphasized. Based on this review, we could conclude that the overall findings corroborate the beneficial effects of AMF–PGPR and/or compost and manure application in terms of boosting date palm’s growth traits, development, yielding, as well as soil properties under extreme environmental factors, such as those of drought, salinity, and excessive heavy metal(oid)s. Thus, biostimulants can confer resilience to date palm plants against abiotic stresses.