Evaluation of Grain Yield and Physiological and Biochemical Trait of Quinoa (Chenopodium quinoa Willd) under Irrigation and Organic Fertilizers

Abstract

Quinoa received worldwide attention due to its ability to grow in different stresses. The grain protein content and its quality are better than other seeds. It is rich in the amino acids lysine, globulin, which makes it suitable for patients with celiac disease. In order to evaluate fertilizer levels under different irrigation regimes on grain yield, physiological and biochemical properties of quinoa, an experiment was conducted during the two cropping years of 2019-20 as split plots in a randomized complete block design with three replications in Birjand, IR Iran. The main factor was irrigation regimes at three levels (100%, 65%, and 30% of reference evapotranspiration) and the secondary factor was fertilizer levels at six levels (control, manure, and vermicompost, NPK, 50% manure+ 50% NPK and 50% vermicompost+ 50% NPK). The highest chlorophyll content with an average of 26.28 mg.gdw^-1 for the first year using irrigation ET0 65% and the application of 50% M+ 50% NPK and its lowest amount with an average of 13.85 mg.gdw^-1 belonged to the first year using ET0 30% treatment with no fertilizer application. Maximum levels of GPX, APX enzymes were observed under severe stress without fertilizer and the lowest levels were observed in 100% evapotranspiration of the reference plant (ET0) with the application of 50% M+ 50% NPK, which showed a significant difference with other treatments. Drought stress affected and reduced quinoa grain yield and the highest dry yield (2496.1 kg ha^-1) was obtained at the control irrigation level in 2019 and there was no significant difference between the two crop years with no stress. However, irrigation up to 65 mm evaporation from Class A pan produces acceptable dry matter, which indicates the good resistance of this plant to drought stress. We can conclude that stress mitigation along with 50% Vermicompost+ 50% NPK happened to be a corresponding hike in biochemical properties, improving physiological aspects and grain yield of quinoa.