THE PERFORMANCE OF DELPHINIUM (Delphinium ajacis (L.) Schur.) PLANTS UNDER DROUGHT STRESS, HYDROGEN PEROXIDE AND SALICYLIC ACID TREATMENTS

چکیده

Greenhouse experiments were conducted during the two successive winter seasons of (2016 –
2017) and (2017- 2018) in order to enhance the performance of Delphinium plants under drought stress conditions
and the possibility of enhancing vegetative growth, flowering growth, and chemical composition. Experiments
were designed as a split-plot based on randomized complete block with three replications in a private commercial
nursery in Damanhour City, El-Beheira Governorate, Egypt. The experiments were conducted by applying foliar
applications of hydrogen peroxide (H2O2) at 0, 1250 and 2500 ppm and salicylic acid (SA) at 0, 100 and 200 ppm.
The vegetative, root and flowering growth and chemical composition of Delphinium plants grown under drought
stress were examined. The obtained results of the two seasons revealed that either SA or H2O2 treatments caused
significant increase in growth parameters and chemical composition of Delphinium plants compare to control
plants. Salicylic acid at a concentration of 100 ppm was more effective in increasing vegetative, root and flowering
growth, and photosynthesis parameters, followed by H2O2 at a concentration of 1250 ppm compared to the other
treatments. On the other hand, H2O2 at a concentration of 2500 ppm was more effective in increasing total phenols
and H2O2 content in leaves.