Effects of chitosan foliar application on quantitative and qualitative characteristics of German chamomile (Matricaria chamomilla L.)under water deficit stress conditions

In order to evaluate the effects of chitosan foliar application under water deficit stress conditions on quantitative and qualitative characteristics of German chamomile (Matricaria chamomilla L.), a study was conducted based on randomized complete blocks design with factorial arrangement of treatments and three replications at Gonbad Kavous University research field, Iran in 2014 growing season. Treatments included irrigation at two levels, irrigation after 60 mm evaporation from class A pan and 100 mm evaporation from class A pan, and chitosan spraying at five levels including non-application of chitosan (spraying with distilled water as control (K1)), chitosan spraying at 125 mg/l after 60 days of planting (K2), 125 mg/l after 75 days of planting (K3), 250 mg/l after 60 days of planting (K4) and 250 mg/l  after 75 days of planting (K5). Results showed that water deficit stress decreased the plant height, number of flowers, plant dry weight and flower dry yield. Foliar application of chitosan increased the number of branches per plant and flower dry yield. Results indicated that utilization of second level of chitosan under stress and third level of chitosan under normal irrigation improved the chamazolen essential oil percentage and yield. According to results of this study, application of chitosan spraying at 125 mg/l after 60 days of planting under deficit water stress conditions caused the highest percentage and yield of essential oil and chamazulene percentage. In general, in order to prevent and reduce the damage of water stress as well as increased chamazulene, the use of bio-polymer chitosan as a natural material in German chamomile is important.