Hydroponic cultivation enhances the morpho-physiological traits and quality flower production in three cultivars (marigold scarlet red, marigold orange, and marigold yellow) of French marigold (Tagetes patula L.)

Abstract

In soil-less agriculture, hydroponic is considered a potential farming system for the production of uniform quality plant material in significantly less time. Therefore, for the first time, the current investigation corroborates the effect of different cultivation conditions (open-field, poly-house, and hydroponic) on morpho-physiological traits, phenolic content, and essential oil components analysis in three French marigold cultivars (marigold scarlet red, marigold orange, and marigold yellow) of Tagetes patula L. The results revealed that the maximum plant height, number of secondary branches, number of flowers, photosynthesis, stomatal conductance, and transpiration rate were observed under the hydroponic system as compared to other conditions. However, the maximum content of gallic acid (0.82 mg/g dry weight), syringic acid (3.98 mg/g dry weight), epicatechin (0.48 mg/g dry weight), p-coumaric acid (7.28 mg/g dry weight), protocatechuic acid (0.59 mg/g dry weight), ferulic acid (2.58 mg/g dry weight), and luteolin (8.24 mg/g dry weight) were quantified under open-field conditions. However, under hydroponic conditions, the higher content of vanillic acid (0.43 mg/g dry weight), caffeic acid (0.49 mg/g dry weight), and quercetin (0.92 mg/g dry weight) were observed. In addition, a total of nineteen volatile components were identified in the essential oil of different French marigold cultivars (marigold scarlet red, marigold orange, and marigold yellow) T. patula L. cultivated under different conditions. The major reported volatile components in essential oil were (-)-caryophyllene oxide, trans-β-caryophyllene, trans-geraniol, 3-methyl-benzyl alcohol, and 2,2′:5′,2″-terthiophene. It has also been observed that the volatile component percentage range in all cultivars was observed in open-field (70.85 % to 90.54 %), poly-house (59.03 % to 77.93 %), and hydroponic (68.78 % to 89.41 %). In conclusion, the research highlighted that maximum morpho-physiological performance with a higher number of flower production per plant was observed under hydroponic cultivation conditions. However, phenolic content and volatile components were maximally observed under open-field conditions. Though, significant results have been reported under hydroponic conditions in all studied parameters, so it could be a potential strategy for quality flower production in T. patula.