Document Type : Research Paper

Authors

1 Ph.D. Student, Agronomy Department, Damghan branch, Islamic Azad University, Damghan, Iran

2 Department of Agriculture, production and technology of herbal medicines research centre, Damghan Branch, Islamic Azad University, Damghan, Iran;

3 Assistant Professor, Filed and Horticultural Crops Research Department, Agricultural and Natural Resources Research and Education Center of Semnan Province (Shahrood), Agricultural Research, Education and Extension Organization (AREEO), Shahrood, Iran

Abstract

The experiment aimed to study the physiological, growth, and yield responses of sesame to the application of potassium nano-fertilizers, chitosan, and fulvic acid under drought stress in Semnan Agricultural and Natural Resources Research Center as a factorial split-plot based on randomized complete block design with three replications in 2019. Experimental treatments included drought as the main plot (normal irrigation, irrigation cut off in 70 and 60BBCH as moderate and severe stress, respectively) and potassium nano-fertilizer (0, 1.5,and 2.5 per thousand) and foliar application (control, chitosan, fulvic acid, and 50% of chitosan+fulvic acid) were performed as sub-plots. Application of potassium nano-fertilizer under normal and stress conditions resulted in a significant increase in chlorophyll b and total, leaf area index, number of capsules, 1000-seed weight, and oil percentage. The highest grain yield was related to the application of 1.5 and 2.5 per thousand nano fertilizers using fulvic acid alone or in combination with 50% chitosan.The highest oil content was in 1.5 and 2.5 per thousand nano fertilizer application under normal irrigation, which increased 13.2% and 15.4%, respectively.Foliar application of fulvic acid with nano potassium fertilizer under severe drought stress showed the highest activity of antioxidant enzymes catalase, peroxidase, ascorbate peroxidase, and superoxide dismutase.In general, the results showed that the application of 1.5 per thousand nano potassium fertilizer and combined foliar application of chitosan and fulvic acid under severe drought by improving physiological traits, leading to the modification of the adverse effects of drought and increasing growth, yield, and quality indices of sesame.

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