Archives of Current Research International

Poor germination and weak early establishment can reduce plant population and productivity in Bt cotton, while zinc deficiency can constrain enzyme activity, reserve mobilization, and root development during establishment. Against this background, the present study evaluated nano zinc oxide (ZnO) seed treatment and seed priming for improving seed germination, seedling vigour, and root development in Bt cotton (Gossypium hirsutum L.) under controlled laboratory conditions. Eight treatments comprising three nano ZnO seed-treatment doses (0.5, 1.0, and 2.0 g kg⁻¹ seed), four seed-priming concentrations (500, 750, 1000, and 1250 ppm), and an untreated control were evaluated in a single laboratory experiment with two independent replications using the between-paper germination method following ISTA guidelines. Germination percentage, seedling vigour indices (SVI-I and SVI-II), and root morphological traits were recorded and subjected to analysis of variance. Nano ZnO significantly improved germination and early seedling growth over the control. Seed treatment with nano ZnO at 1.0 g kg⁻¹ seed recorded the highest germination (92%), SVI-I (3119), SVI-II (43001), root length (326.7 cm), root volume (1.92 cm³), and root surface area (82.8 cm²). Among seed-priming treatments, 1000 ppm nano ZnO produced superior seedling performance. Thus, nano ZnO at an appropriate concentration enhanced early establishment and root development in Bt cotton; however, these findings are limited to laboratory conditions and require nursery and field validation before agronomic recommendation.