The 2012 ASHS Annual Conference

There are numerous references that classify plants based on the salt tolerance.  However, many of these references are based on observational data and may not be accurate.  The objective of this study was to develop a protocol that could be used to verify salt tolerance of ornamental species.  Rose of Sharon (Hibiscus syriacus) has been reported to be a salt tolerant plant while Sea Hibiscus (Hibiscus tiliaceus) has been classified as a salt intolerant plant.  Five replicates of 10 rooted cuttings from Rose of Sharon and Sea Hibiscus were placed in 3 L containers filled with 2 L of solutions.  The solutions varied in EC concentrations of 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 dS/m.  The solutions were prepared by mixing marine aquarium salt with distilled-deionized water until the desired EC was achieved.  Solutions were changed every day and leaf water potential of each plant was compared with control to determine salt stress.  For each plant species the lethal concentration that killed 10% of the population were calculated.