Effect of planting date and salicylic acid on some quantitative and qualitative traits of quinoa as affected by drought stress

This study was conducted as split-split-plot based on randomized complete block design with three replications at experiment station of the Agricultural Faculty of Bardsir, Shahid Bahonar University of Kerman at 2018. The experimental treatments were planting date (5 April, 5 May and 5 June) assigned to main plot, irrigation levels (90, 60 and 30% of filed capacity) as subplot and foliar application (salicylic acid 1 mM and water) as sub-subplot. The results showed that the delay in planting date shortened the Quinoa growth period. GDD and growth period were decreased by drought stress. May planting date has significantly higher root length (31.81 cm) and dry weight (9.09 g plant-1) than two other planting dates. The highest root length for April (28.27 cm) and May (35.92) planting dates was assigned at 60% of FC, while for June (21.27 cm) was related to no-stress condition. Averagely, grain yield for May (653.91 kg ha-1) planting date was significantly higher than April (578.7 kg ha-1) and June (460.8 kg ha-1). Decrease in consumed water to 60% of FC had no significant effect on grain yield, but the trait value in 30% of FC was significantly lower than other irrigation levels. Justly at severe drought level, grain yield was significantly increased by foliar application of salicylic acid than water application. Relationship of grain yield was positive with grain oil percentage (r = 0.82) and was negative with protein percentage (r = -0.78). Water use efficiency (WUE) was significantly higher in May planting date than in April and June planting date. WUE increased significantly with water consumption decreasing. Generally, the results illustrated that May planting date is the most suitable planting date for Quinoa in Bardsir regions and same climates. Results showed that the plant has a considerable tolerate in water stress condition.