Production and ion uptake of Celosia argentea irrigated with saline wastewaters

Abstract

The reuse of saline wastewaters and groundwaters becomes a viable option for the irrigation of salt tolerant floral crops as competition for high quality water increases. A completely randomized design with three replications was used to assess the effects of two water ionic compositions and six salinity levels on the production and mineral accumulation of two cultivars of Celosia argentea var. cristata (L.) Kuntze under greenhouse conditions. Ionic water compositions mimicked sea water and saline drainage waters of the Imperial and Coachella Valleys of California. Electrical conductivity levels included 2.5 (control), 4.0, 6.0, 8.0, 10.0, and 12.0 dS m −1. Seeds representing the two cultivars (“Chief Rose” and “Chief Gold”) were sown in 36 greenhouse sand tanks. Leaf mineral concentrations were determined 1 month from planting for Ca 2+, Mg 2+, Na +, K +, Cl −, total-S, and total-P. Phenotypic measurements were taken when plants were harvested after flowering. For both cultivars and ionic water compositions, concentrations for Ca 2+, K +, and total-P decreased as salinity increased whereas Mg 2+, Na +, and Cl − concentrations increased with increasing salinity. Significant two-way interactions were found between water ionic composition and salinity for all mineral concentrations for both cultivars ( P < 0.05). All phenotypic measurements showed an overall decrease as salinity increased for both cultivars. Based on stem length measurements, “Chief Gold” may be produced for commercial use in saline waters with electrical conductivities of 12 dS m −1 in both water compositions. “Chief Rose” may be produced in salinity concentrations up to 10 dS m −1 for water compositions similar to the Imperial and Coachella Valleys and up to 8 dS m −1 for water compositions similar to sea water. Producing cut flowers in saline waters also reduces excessive stem length, which occurs when plants are grown in control treatments.