Amin Abbasi

Drought stress is one of the important environmental stresses that affects plants biologically. In order to investigate the effect of ascorbic acid spraying on the amount of chlorophyll content of the leaves of the savory plant under water stress conditions, an experiment was carried out as factorial experiment conducted based on a randomized complete block desing with three replications in the greenhouse of Maragheh University in 2021. The main factor includes water stress at three levels. The main factor includes water stress at three levels, 90% of field capacity (as no-stress conditions) and 60 and 30% of field capacity, and the secondary factor also includes the control (not spraying of ascorbic acid) and spraying ascorbic acid at concentrations of 150 and 300 µM. According to the results, chlorophyll a, chlorophyll b, Chlorophyll a/b, total chlorophyll and carotenoid were affected by the effect of intraction of water stress × ascorbic acid spraying. According to the results obtained from this research, the highest amount of chlorophyll a, chlorophyll b, Chlorophyll a/b, total chlorophyll and carotenoid was obtained from the spraying of 300 µM ascorbic acid in 90% field capacity. The lowest values of the traits are related to the treatment of not using ascorbic acid in the 30% field capacity. Also, the results showed that spraying of 300 µM ascorbic acid at 30% field capacity increased chlorophyll a, chlorophyll b, Chlorophyll a/b, total chlorophyll and carotenoid traits by 20, 23, 115, 49 and 9%, respectively compared to not spraying ascorbic acid in the 30% field capacity. In general, it can be said that the use of ascorbic acid at 300 µM concentration, especially in high stress intensities, due to the increase of photosynthetic pigments is so usefull combination.