Germination and seedling growth of okra: A comparative study with competitive weeds under salinity stress

Abstract

This study explores the effects of salinity stress on the germination and seedling growth of okra (Abelmoschus esculentus) and its competitive weeds. The experiment was conducted under controlled conditions with a factorial combination of four salinity levels (0, 5, 10, and 15 mM NaCl) and three plant species (okra, Portulaca oleracea, and Cynodon dactylon) arranged in a completely randomized design, having four replications each. Data were collected on germination percentage (GP), germination energy (GE), germination rate index (GRI), mean germination time (MGT), and seedling vigor index (SVI). The results demonstrated that increasing salinity levels significantly negatively affected the plant species germination and seedling growth, as the higher the concentration the stronger the effect. Increasing salinity levels from 5 to15 mM concentration caused a reduction in GP from 25 % - 98.1%, GE from 33.3 % - 93.6 %, GRI from 39.2 % - 98.6 %, and SVI from 41.1 % - 99.9 % compared to the control. In contrast, P. oleraceae showed higher resilience to salinity stress, maintaining superior GP, GRI and SVI compared to okra and C. dactylon. The C. dactylon exhibited moderate tolerance to salinity between okra and P. oleraceae. The findings have shown the competitive disadvantage of growing okra in saline environments and suggest that P. oleraceae could exacerbate weed competition under such conditions. This study highlights the need for targeted weed management strategies and the development of salt-tolerant okra varieties to improve its production in salt-affected regions.