exogenous application of growth-stimulating substances alleviated the effects of water-deficit stress on the spring camelina sativa

A field experiment aimed to evaluate the agronomic characteristics of the spring camellia plant in different soil moisture conditions (100% fc or well-watered and 50% fc or water-deficit stress) and foliar spraying with ascorbic acid (concentration of 10 and 20 mm) and salicylic acid (0.6 and 1.2 mm) in the semi-arid region of maragheh in the northwest of iran (47°53′ e, 37°93′ n; 1682 m above sea level). the results showed that water shortage stress caused a significant decrease in plant height (13%), canopy width (43%), seed yield (22%), number of days to maturity (13%), and number of siliques plan-1 (44%). however, external application of high concentrations of ascorbic acid and to some extent salicylic acid could improve vegetative growth in both irrigation conditions. the highest number of days to maturity (128 days) was recorded with the application of 1.2 mm salicylic acid solution under well-watered conditions. foliar application of ascorbic acid under water-deficit stress conditions improved the chlorophyll content by 28% compared to the control (s0: spraying with distilled water). foliar spraying with 10 mm ascorbic acid could increase the number of seeds silique-1 under both water-deficit stress (58%) and well-watered (36%) conditions when compared with control. the highest seed yield was obtained with foliar spraying of 20 mm ascorbic acid under well-watered conditions. this foliar treatment could improve the seed yield by 13% under well-watered conditions and 16% in water-deficit conditions compared to the control. under water shortage conditions, high concentrations of ascorbic acid and to some extent, salicylic acid can alleviate the effects of drought stress. the results showed that the exogenous application of 10 mm ascorbic acid was very efficient under well-watered conditions. however, spray of growth-stimulating substances was able to alleviate the destructive effects of drought stress to some extent.