Response of quinoa (Chenopodium quinoa) cultivars to organic acid under drought stress

The present study was an attempt to delve into the responses of two quinoa cultivars treated with humic and amino acids to drought stress. the experiment was conducted based on a split plot arrangement in a randomized complete block design with three replicates during 2019-2020. experimental factors included drought stress at three levels (50, 80, and 110 mm evaporation from evaporation pan class a), cultivar at two levels (titicaca and q29), and organic acids at four levels (control, humic acid, amino acid, and a combination of humic and amino acids). findings suggested that extreme drought stress resulted in the decreasing of 20.33% plant height, and 30.19% of leaf area index while increasing 78.69% malondialdehyde content as well as 8.12% catalase and 31.26% peroxidase enzymes activities. titicaca cultivar had higher plant height, leaf area index, and catalase contents (93.32%, 9.98%, and 13.38%, respectively) as compared with q29. applying organic compounds improved growth and biochemical properties of quinoa plants with the maximum positive effect in plants treated with a combination of humic and amino acids. these compounds also decreased the negative effects of drought stress. application of humic and amino acids seems to improve vegetative parameters of quinoa plants under both normal and drought stress conditions through increasing antioxidant enzyme activities and regulation of abscisic acid hormone.