The Effect of Manure Application on Physiological Traits of Cichorium intybus L. in Response to Drought Stress

Abstract Background & Objective: Essential elements in animal manure are needed at sufficient levels to complete the plant growth cycle and have an important effect on improving the quantitative and qualitative yield of Chicory plant. Thus, this study was done to investigate the effect of different levels of irrigation and animal manure on physiological characteristics of chicory.   Materials & Methods: A factorial experiment was conducted in a randomized complete block design with three replications at the Faculty of Agriculture, Urmia University of Agriculture in 2017. Experimental treatments consisted of three levels of moisture (50, 70 and 90% of field capacity) and four levels of manure application (0, 10, 20 and 30 ton.ha-1).   Results: The results showed that with delay in irrigation the content of photosynthetic pigments and DPPH radical scavenging were significantly decreased. However, the highest amount of malondialdehyde and hydrogen peroxide was obtained under severe stress conditions. Application of 30 ton/ha of manure increased chlorophyll a, chlorophyll b, total chlorophyll and carotenoid levels. The amount of hydrogen peroxide and malondialdehyde decreased significantly with increasing amounts of animal manure. Total phenol, flavonoid, phosphorus and potassium content increased by 39, 29, 25 and 27% in optimum irrigation conditions and 28, 25, 16 and 23% in moderate stress conditions and 22, 18, 14 and 20% in severe stress conditions, respectively, by application of 30 ton/ha of manure compared to the control treatment. Maximum protein percentage (19.66%), biomass yield (2506.83 kg.ha-1) and protein yield (493.04.04 kg.ha-1) were obtained at 30 ton/ha/ manure under optimum irrigation conditions.   Conclusion: Therefore, according to the findings of this study, in the condition of water deficiate, application of animal manure in the condition of water deficiate, improved Cichorium medicinal plant performance and stability.