Objective: This study aimed to investigate the effect of sodium nitroprusside foliar application (SNP) on the performance of henna (Lawsoniainermis L.) ecotypes under drought stress conditions.

Methods: The experiment was conducted using a completely randomized design with a factorial arrangement. The factors included three henna ecotypes (Shahdad, Bam andRudbar-e-Jonub), three levels of irrigation (100, 75 and 50% of field capacity) and spraying (control and sodium nitroprusside). Various growth and physiological parameters were measured to assess the performance of henna under different treatments.

Results:With a decrease in water level, the amount of photosynthetic pigments, growth indices, net photosynthesis, and ultimately leaf dry matter yield decreased. However, the application of sodium nitroprusside spray treatment was able to significantly increase leaf surface index, product growth rate, net photosynthesis, and leaf dry matter yield compared to the control treatment at irrigation levels of 75% and 50% of the agricultural capacity. Among them, the highest percentage increase in the measured traits was related to the Shahdad genotype.

Conclusions: This study provides valuable insights into the potential of SNP foliar application in enhancing the performance of henna plants under drought stress conditions. The findings highlight the importance of selecting suitable henna ecotypes for cultivation in regions prone to drought stress. Additionally, the study contributes to the limited literature on the use of SNP as a potential tool for improving plant tolerance to drought stress. Bottom of Form