Quinoa (Chenopodium quinoa Willd.) has attracted attention in agricultural community as alternative crop in harsh climatic regions due to its high tolerance level under biotic and abiotic conditions. Natural and synthetic growth enhancers are supposed to boost up the growth, development and economical yield of field crops under normal and unfavourable growing conditions. Two successive field experiments were conducted to explore the impact of moringa leaf extract (MLE), sorghum water extract (sorgaab), hydrogen peroxide and ascorbic acid on growth and grain quality of quinoa cultivated under normal and late sown conditions. MLE at 3%, sorgaab at 3%, hydrogen peroxide at 100 µM and ascorbic acid at 500 µM were applied at anthesis stage of crop cultivated during growing seasons of 2016–2017 and 2017–2018. Seeds of quinoa genotype UAF-Q7 were sown at Research Area of Directorate of Farms, University of Agriculture, Faisalabad-Pakistan. All the foliar treatments significantly improved the physiological and growth attributes. Maximum improvement in synthesis of chlorophyll (29% and 12%) and carotenoids contents (42% and 28%) and net rate of photosynthesis (58% and 70%) and respiration (26% and 14%) was recorded by MLE application over control (no spray) under normal and late sowing. Mineral elements, antioxidants activities and seed protein contents were also improved by all foliar treatments but mainly by MLE application. MLE application produced highest grain (47%) and straw (52%) yields under normal and late sown environments. Application of MLE is considered good biostimulant to improve the productivity and yield of quinoa crop cultivated under normal and even in late sown circumstances.