Impact of foliarly applied morigna leaf extract for the mitigation of salt stress in Chenopodium quinoa genotypes: growth, physiological and ionic modifications

Abstract

Salinity poses a significant threat to crop production and food security, particularly in regions like Pakistan where salt-tolerant crop options are limited. While some salt-tolerant forage species exist, the need for salt-tolerant cereal crops is crucial. Quinoa, a pseudo-cereal renowned for its high nutritional value and tolerance to abiotic stresses including salinity, presents a promising solution. Under saline conditions, quinoa's protein content can increase, but overall productivity is often reduced. This limitation can potentially be addressed by applying moringa leaf extract (MLE), a natural biostimulant rich in micronutrients, antioxidants, and growth promoters. To investigate this, a greenhouse experiment was conducted at two salinity levels (ECe = 10 and 20 dS m⁻¹) to assess the effects of foliar MLE application on quinoa grain production and nutritional attributes. The experiment utilized a completely randomized design with three replicates. Post-harvest analysis revealed that foliar MLE application positively influenced quinoa growth, significantly enhancing its salt tolerance. This improvement is attributed to MLE's chemical composition, which facilitated reduced sodium (Na⁺) accumulation and increased potassium (K⁺) and calcium (Ca²⁺) concentrations in both leaves and seeds, ultimately improving plant growth and yield. Notably, among the genotypes tested, UAF-Q7 exhibited greater inherent salt tolerance than UAF-Q9, with MLE application further augmenting this resilience. This study highlights the potential of foliar MLE application as a viable strategy to mitigate salinity stress in quinoa, especially in salt-affected agricultural regions of Pakistan, contributing to enhanced food security