Foliar application of moringa leaf extract (MLE) enhanced antioxidant system, growth, and biomass related attributes in safflower plants

The use of synthetic fertilizers is a potential source of environmental hazards. Natural plant-based growth regulators are eco-friendly, inexpensive and their use is highly recommended. Moringa (Moringa oleifera L.) is also known as a miracle plant with high nutritional content, medicinal and plant growth-promoting properties due to the presence of appreciable levels of hormones, vitamins, micro, and macronutrients. However, no literature has been found regarding the effect of moringa leaf extract (MLE) application on safflower plants (Carthamus tinctorius L.). Therefore, the present experiment investigated the effect of two different concentrations of MLE (3 and 20%) on various biochemical, mineral content, growth, and biomass-related attributes of safflower plants. Results revealed that application of MLE significantly improved chlorophyll content, maximum quantum yield of photosystem II (Fv/Fm), shoot and root length, fresh and dry biomass. Moreover, MLE application also significantly enhanced activities of leaf superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) while decreasing H₂O₂ and MDA content. Foliar application of MLE also resulted in a notable increase in proline, glycine betaine, and mineral content. The application of MLE (20%) manifested maximum improvement in all attributes when compared to MLE (3%). Pearson's correlation analysis revealed positive correlation among growth, biomass, biochemical and mineral content, whereas a strong negative correlation was found between these traits and oxidative stress markers (H₂O₂ and MDA) under MLE application. The present experimental findings indicate that MLE application can be employed as a natural plant growth regulator. Furthermore, the MLE enhanced the antioxidant system and reduced oxidative stress, therefore, it can be used to ameliorate the detrimental effects of environmental adversities on plants.