Effect of growth biostimulators on flower and seed yield parameters of Calendula officinalis

Abstract

Calendula.officinalis is a medicinal plant species known for centuries and it is widely used in cooking, medicine and numerous processing industries. In an attempt to improve the productive properties of C. officinalis in pots, an experiment was conducted at the experimental field of the Institute for Medicinal Plants Research "Dr. Josif Pančić" Belgrade, Serbia. This work aimed to examine the influence of organic growth biostimulators on the flower and seed yield parameters of C. officinalis grown under semi-controlled conditions. The experiment contained two treatments by priming C. officinalis seeds for 20 minutes, organic biostimulators (EkoBooster1 - E and Algo Fast - A) and one control treatment (K) in distilled water. The results of the experiment showed that the yield parameters during the first four harvests were significantly better in the treatments with biostimulators, while in the later harvests the yield parameters were better in the control treatment. In contrast to the treatments with biostimulators (A) and (E), the yield of seeds per plant (9.2 and 8.9) was significantly better in the control treatment (K-12.8), while the percentage of germinated seeds did not differ significantly between treatments (A:91.3 %; E: 90.2%; K: 92.4%). The outcome of this study shows us that biostimulators have a positive effect on the parameters of marigold flower yield in the initial stages of harvest, while they did not have an excessive effect on seed yield.