RESPONSE OF LISIANTHUS TO IRRIGATION WITH SALINE WATER: PLANT GROWTH

Abstract

Production of cut flowers in California is located mostly in the coastal areas, where sea water intrusion is a problem, or in the southern inland valleys, where water quality and quantity are prevalent issues. In recent years there has been an increasing interest as to the feasibility of commercial production of ornamental plants using degraded waters. The present study was conducted in greenhouse sand cultures to compare the growth and development of lisianthus in response to irrigation with solutions differing in ionic composition and concentration to mimic either well waters contaminated with sea water (sea water dilutions, SWD) or tailwaters typical of concentrated Colorado River water (CCRW). Seedlings of lisianthus ‘Pure White’ were irrigated with varying electrical conductivity (EC) treatments, ranging between 2 to 12 dS · m⁻¹. The results showed that lisianthus ‘Pure White’ grew better when irrigated with EC = 2 dS · m⁻¹ SWD, although commercially acceptable flowering stems were produced in treatments as high as 7 dS · m⁻¹. Lisianthus can also be irrigated with CCRW tailwater with EC ≤ 6 dS · m⁻¹ for ‘Echo Blue’ or with EC ≤ 8 dS · m⁻¹ for ‘Pure White.’

Keywords:

• cut flowers
• Colorado River Water
• salinity
• sea water dilutions
• water reuse