Assessment of ornamental grass accessions under varying salinity levels

Abstract

Lawns play a key role in enhancing public spaces, preventing soil erosion, and acting as barriers against dust and sludge. In Brazil, Paspalum notatum is widely cultivated for its adaptability to the country’s ecosystems and the availability of native ecotypes. However, soil salinization, a growing ecological concern, can limit lawn growth due to sodium and chloride ion toxicity. This study aimed to identify the most tolerant among five genotypes (Aruaí and Tiriba cultivars, BRA 010006 and BRA 019178 accessions and the commercial species Axonopus fissifolius) subjected to salinity levels (0.5, 1.5, 3.0, 4.5, and 6.0 dS m-1). Analyzed variables included Na and Cl contents in plants, growth parameters (leaf and root dry mass and soil coverage), and morphological symptoms. No significant changes in leaf color or damage compromising aesthetics or functionality at salinity levels from 0.5 to 1.5 dS m-1, with only occasional yellowing or minor scorch. Higher salinity led to leaf burn and yellowing, particularly in accession BRA 010006 and the control. Sodium and chloride contents, especially sodium, was higher in roots than leaves. Accession BRA 019178, followed by cultivars Aruaí and Tiriba, demonstrated moderate tolerance, maintaining satisfactory soil coverage and dry mass across the tested salinity levels. These findings highlight the importance of selecting native turfgrasses with enhanced salt tolerance for landscaping applications in saline-prone areas.