Developmental, Phytochemical and Enzymatic Changes in Pot Marigold (Calendula officinalis L.) cvs. Hybrid and French with Salicylic Acid (SA) and Polyamine Spermidine (SP) Foliar Spray

Marigolds (Calendula officinalis L.) are valuable in ornamentation, human food, and other uses; to enhance productivity, plant growth regulators produce stimulatory effects, including salicylic acid (SA) spermidine (SP), but there is a lack of scientific evidence about such effects marigolds. The study assessed, under greenhouse conditions, changes physico-chemical parameters, enzymatic activity, bioactive compounds marigold cvs. Hybrid French marigolds were sprayed SA (1 2 mM) SP (2 3 compared control (pure water). at mM improved leaf length (8.20 cm), flower height diameter (5.32, 8.28 fresh dry weight (14.30, 1.5 g), the maximum number petals (55) ‘Hybrid’. Similarly, gave leaves (40.71) stem thickness (5.76 mm) ‘French’, promoted Superoxide dismutase, peroxidase, catalase activities increased ‘Hybrid’ with SA; this dose, had higher contents total phenolic (68.34 mg GAE g−1), antioxidants (77%), carotenoids (110 100 flavonoids (67.5 RE g−1) than control. best dose for improving both varieties was SA.