Growth and Flowering Response of Marigold (Tagetes erecta) to Salt Stress

Abstract

M arigold (Tageteserecta L.) is herbaceous annual plant belongs to the family Asteraceae (Kumar et al., 2016). Marigold is used both for ornamental and medicinal purposes. It is also used in cosmetic and perfume industry due to its aromatic nature and essential oil contents (Regaswamy and Koilpillai, 2014). Marigold is a major seasonal flowering plant grown in the public parks, gardens, and roadside Abstract | Salt stress is major concerns to agriculture globally. Salt stress interferes enzymatic activities and several physiological processes that lead to reduction in crop yield and quality. The current investigation was performed at Horticulture Garden where two marigold cultivars (V 1 = African orange and V 2 = Dwarf double mix) were subjected to salinity stress condition (0, 2, 4, 6 and 8 dS m -1 ). The results exhibited that salt stress revealed adverse effect on all the parameters of both of the varieties of marigold. The plants irrigated with canal water (control) having EC of 0.7 dSm -1 showed better results for both seed and flowering related traits. The plants treated with canal water showed better seed germination (82.56 %), seed germination index (2.04), plant height (21.31 cm), branches/plant (45.61), leaves/plant (201.67), flowers/plant (8.56), diameter of flower (7.95 cm), fresh root biomass (0.821 g) and dry root biomass (2.28 mg). The plants treated with 2 dSm -1 showed seed germination (65.35 %), seed germination index (1.53), plant height (16.61cm), branches/plant (40.38), leaves/plant (195.33), flowers/plant (6.83), diameter of flower (6.75 cm), fresh root biomass (0.718 g) and dry root biomass (2.04 mg). It was further noted that as the salt stress increases the plant performance for all investigated traits decreased significantly. The varieties showed highly different responses for both seed and flowering related attributes. The variety dwarf double mix had a better seed germination and flowering growth and production in comparison with African orange. The double mix showed better seed germination (64.64 %), seed germination index (1.53), plant height (14.94 cm), branches/plant (36.71), leaves/plant (190.73), flowers/ plant (5.64), diameter of flower (6.32 cm), fresh root biomass (0.660 g) and dry root biomass (2.12 mg). It is concluded that salt stress up to 0.7 dSm -1 did not reveal any adverse effects on germination and flowering response of marigold. The salinity at 2, 6 and 8 dSm -1 caused simultaneous adverse effects on all the studied parameters.