Investigation of the effect of drought stress and foliar application of zinc and manganese on yield and some physiological characteristics of quinoa (Chenopodium quinoa Willd.)

Calculating water use efficiency and utilizing micronutrients in arid areas can help save water consumption and reduce the effects of drought stress. This experiment was conducted to investigate the different levels of irrigation and spraying with zinc and manganese in 2019 in research field of Saravan Higher Education Complex as split plot in a randomized complete block design with three replications. Experimental treatments consisted of three levels of irrigation (50, 80 and 110 mm evaporation from Class A evaporation pan - equivalent to mild, moderate and severe stress, respectively) as main plot and foliar application with zinc sulfate (three per thousand), manganese sulfate (three per thousand) and non-foliar application as sub plot. The results showed that the highest rate of electrolyte leakage was observed in 110 mm evaporation from the pan and no foliar application and the highest amount of RWC was observed in the 50 mm evaporation treatment from the pan, under foliar application with zinc and manganese elements. By increasing evaporation rate from 50 to 110 mm in the pan, the RWC content decreased significantly. Also, with increasing the stress intensity from 50 to 110 mm of evaporation, the number of seeds per plant decreased significantly. The highest biological and seed yields were observed in the 50 mm evaporation treatment. In addition, foliar application with zinc sulfate caused a significant increase of 21.2% and 25.9% in biological and seed yields compared to non-foliar conditions. Treatment of 50 mm evaporation from the pan was higher in a rate of 60% and 19.5% water use efficiency of biomass and seed, respectively than irrigation treatment based on 110 mm evaporation. Also, the highest water use efficiency of biomass and seed was observed in zinc sulfate treatment. In generally, irrigation based on 110 mm evaporation from the pan for quinoa was recommended in Saravan climate and it seems that foliar application of zinc sulfate can be used as an agricultural solution to increase the yield of this plant.