B. O. EDEGBAI

Soil salinity is one of the major environmental problems limiting seed germination and crop productivity in tropical agriculture. Corchorus olitorius L. (jute) is an important fibre and vegetable crop in Nigeria, yet its early growth is highly sensitive to saline conditions. This study evaluated the physiological response of two jute landraces. Landrace C (from NIHORT) and Landrace D (from Delta State) were treated to different salt concentrations to determine their level of tolerance. The experiment was conducted using a Completely Randomized Design (CRD) with five sodium chloride (NaCl) levels: 5 ppm (control), 200, 2000, 5000, and 10,000 ppm, each replicated three times. Growth parameters observed included germination percentage, shoot height, number of leaves, stem girth, number of branches, internode length, and leaf area. Data collected were analyzed using Analysis of Variance (ANOVA) at a 5% significance level. Results showed that salt stress caused a steady decline in all growth parameters. Landrace C had the highest germination rate (90.00 ± 17.32%) and best seedling growth at 200–2000 ppm, recording maximum shoot height (26.83 ± 4.64 cm) and leaf number (34.67 ± 1.70). Landrace D performed poorly, with peak germination at 200 ppm (20.00 ± 0.00%) and no growth beyond 2000 ppm. Analysis of variance (ANOVA) indicated significant differences (p < 0.05) among treatments and between landraces. Overall, Landrace C exhibited stronger salt tolerance due to better osmotic adjustment and growth stability, making it suitable for cultivation and improvement in saline prone soil.

Salt stress is an abiotic factor which poses significant threat to plant growth and productivity. A variety of plants are sensitive to salinity, one of which, is Corchorus olitorius. This study investigated the effect of salt stress on the germination, seedling growth, and physiological responses of Corchorus olitorius seeds collected from Benin (Landrace B) and National Horticultural Research Institute (NIHORT) designated as Landraces C. This experiment was conducted to determine how different concentrations of sodium chloride (NaCl) influenced germination percentage and the various growth parameters namely shoot height, number of leaves, leaf area, stem girth, number of branches, internode length, and leaf loss. The seeds were subjected to five treatments including control (5 ppm NaCl solution) and other varying salt concentrations (200 ppm, 2000 ppm, 5000 ppm, and 10000 ppm). Data collected were subjected to Analysis of Variance (ANOVA) to determine the level significance of the treatments. The results revealed significant differences in the parameters investigated. Increasing salinity levels significantly reduced germination rate, shoot elongation, and overall seedling establishment. The treatments with concentrations below 2000ppm recorded the highest mean values for germination percentage and growth parameters, while the treatments with the highest concentration of salt exhibited severe inhibitory effects leading to reduced germination rate, stunted growth, and poor seedling development. These findings demonstrated that C. olitorius is sensitive to high salinity levels, and salt stress adversely affects its early growth stages. It also reveals that C. olitorius seeds from Benin city were more sensitive to salt stress compared to C. olitorius seeds from NIHORT as higher germination percentage and growth were observed in landrace C.