Effects of different plant populations of African night shade (Solanum nigrum) varieties on the vegetative growth parameters across two distinct agro-ecological zones (Bali and Jalingo) in Taraba state, Nigeria.

A two-site factorial experiment was conducted during the 2024 rainy season in Bali and Jalingo, Taraba State, Nigeria, to evaluate the growth and leaf yield of three African nightshade (Solanum nigrum) varieties: Mbamga (V1), Mange (V2), and Pala Pala (V3). The study employed a 3 × 5 factorial arrangement in a Randomized Complete Block Design, investigating the effects of the three varieties and five plant spacing treatments (S1: 20×30 cm, S2: 25×30 cm, S3: 30×30 cm, S4: 35×30 cm, and S5: 40×40 cm). Data on vegetative growth and leaf yield were subjected to Analysis of Variance (ANOVA). Significant varietal differences (p < 0.05) were observed across all measured parameters. Pala Pala (V3) consistently exhibited the largest leaves across both locations, with maximum leaf length (10.176 cm) and width (7.558 cm) recorded at 6 Weeks After Transplanting (WAT) in Bali under S5 spacing. Mange (V2) demonstrated superior branching capacity (9.91 branches/plant at S5) and greater plant height (35.55 cm in combined analysis). Wider spacing (S5) significantly promoted larger leaf size (leaf length: 8.10 cm vs S1: 5.22 cm in combined analysis) and increased plant height (S5: 32.59 cm vs S1: 25.46 cm). Leaf yield analysis identified V3 and V2 as superior producers. Maximum yields per plant were recorded at 40×40 cm spacing (V3: 2,613.9 g/plot in Bali; V2: 2,599.8 g/plot). However, the highest yield per unit area was achieved at the closest spacing (20×30 cm), producing 2,775.8 g/plot in Bali. A significant variety × spacing interaction was observed (p < 0.01). Location effects were highly significant, with Bali outperforming Jalingo across all parameters due to more favorable rainfall (1,850 mm vs 1,058 mm) and temperature regimes. Optimal spacing varied with production objectives: 20×30 cm with V2 and V3 maximized leaf yield per unit area. These findings underscore the importance of site-specific recommendations for enhancing African nightshade productivity.