Effects of hydropriming and foliar application of chitosan and humic acid on physiological and agronomic characteristics of borage

To investigate the effects of hydropriming and foliar application of chitosan and humic acid on physiological and yield characteristics of borage, a factorial experiment was carried out based on a randomized complete block design with three replications at Medicinal Plants Research center of Samian Ardabil in 2017. Treatments were seed priming in two levels (non-priming (control) and hydropriming for 48 hours), and foliar application in four levels (control, 0.5 g.L-1humic acid 1 g.L-1 chitosan and combination of humic acid and chitosan). Results showed that hydropriming significantly improved the grain yield (1.23 fold) and yield components of borage plants compared to control; may be through the increasing in the photosynthetic pigments content. Foliar application of humic acid, chitosan and combination of humic acid and chitosan, significantly increased the flower yield in the plants obtained from primed seeds. Although hydropriming increased the 1000-grain weight and grain yield, the foliar application caused a further increase these traits, so that, in the plants from primed seeds, the foliar application of humic acid and utilization of humic acid and chitosan were significantly increased the 1000-grain weight (1.22 fold) and biological yield (1.69fold) compared to control, respectively. These results indicate the synergistic effects of hydropriming and utilization of humic acid on borage growth and yield characteristics under field condition.