The Effects of Deficit Irrigation, Planting Date and Biofertilizers on Phenological Traits, Yield and Quality of Quinoa

In order to investigate the effects of irrigation, planting date, and biofertilizers on phenological traits, yield, and some qualitative traits of quinoa as a new plant, an experiment has been conducted on a farm located in Bilehsvar region of Ardabil Province in two cropping years from 2019 to 2021 in split - split plot design based on a randomized complete block design with three replications. Experimental factors include irrigation at three levels, including (complete irrigation, irrigation termination in budding stage, and irrigation termination in seed filling stage) as the main factor, planting date at three levels (namely 27 July, 11 August, and 27 August) as the sub-factor, and four levels of nitrogen biofertilizer (the control, seed inoculant with Azotobacter, inoculant with Azospirillum, and inoculation with a mixture of Azotobacter and Azospirillum) as the sub-sub-factor. The results show that the use of complete irrigation with a planting date of 27 July and inoculation of Azotobacter and Azospirillum biofertilizers has increased the length of phenological stages and 1000-seed weight. In terms of harvest index, complete irrigation treatment with planting date of 27 July, and combined inoculation of biofertilizers have had the highest value, in terms of protein percentage and saponin content of seed, irrigation interruption at the budding stage with planting date of 27 July, while co-inoculation with biofertilizers has given the best results, and the highest biological yield (620 g/m2) and grain yield (304.97 g/m2) have been obtained from complete irrigation treatment with planting date of 11 August and co-inoculation of biofertilizers.