Effects of different NaCl Concentrations on germination and seedling growth of <i>Amaranthus hybridus</i> and <i>Celosia argentea</i>

Abstract

Salinity refers to the salt content of any given system. By nature, arid soils are naturally saline. Soils could also acquire salinity due to some agricultural practices like irrigation. There is need therefore for search on halophytes that could adapt to such soils and be used to reclaim soils contaminated with salts. Thus, this present study focused on investigating Amaranthus hybridus and Celosia argentea with respect to their potentials and suitability for use in saline environments. This study was conducted in two phases; germination (laboratory-based) and seedling tests (field-based). Shoot length, root length, root/shoot ratio, total length, fresh weight, dry weight, dry matter content, leaf area index, leaf number as well as relative water content were parameters used for assessing results for the field-based test. Germination results showed that only the control (0 mM) showed 100 % germination in both species. Germination percentages decreased steadily with increasing NaCl concentrations in both species. Growth was steadily stimulated in both species at lower NaCl levels with best growth stimulation at 50 mM NaCl but was adversely affected by higher NaCl concentration levels (75, 100 and 150 mM). Both species showed almost the same phenomenon for fresh weight, dry weight, dry matter, leaf area index, number of leaves as well as relative water concentration. These show that both species would best be cultivated under moderate than low or high saline concentration. The findings in this study showed that it is best for seedlings of both species of plants to be raised in nurseries free of NaCl to attain 100% germination and after which, the seedlings could then be transplanted to moderately saline soils for maximum growth and development. This has strong implications for maximizing food productivity and ensuring food security. 

Key words: Germination, early seedling growth, NaCl, salinity, Amaranthus hybridus, Celosia argentea.