Purpose: A field experiment was conducted at Dharwad, Karnataka, during 2017-18 to evaluate the effect of seed treatment and foliar application of nano ZnO on nutrient status of Bt cotton.

Method: The experiment was laid out in split plot design with three main treatments (M₁:seed treatment with chelated ZnSO₄ @ 4 g kg^-1 seeds, M₂: nano ZnO @ 1 g kg^-1 seeds and M₃:seed priming with 1000 ppm nano zinc solution), four sub plot treatments (Foliar application of nano ZnO @ 500, 750, 1000 and 1250 ppm at square initiation and flowering stage) and three uneven control (C₁: RDF + FYM + 0.5 % EDTA ZnSO₄ foliar application at square initiation and flowering stage, C₂: C₁ + seed treatment with Fe, Zn, Mg and Mn @ 4g each kg^-1 seed and C₃ : Only RDF + FYM @ 5.0 t ha^-1) treatments replicated thrice.

Result: Among seed treatments, higher seed cotton yield (2842 kg ha^-1) recorded with nano ZnO seed treatment than seed priming with nano zinc solution and chelated ZnSO₄ seed treatment.

Conclusion: Among all treatment combinations, seed treatment with nano ZnO in combination with foliar application of nano ZnO @ 1000 ppm recorded significantly higher nutrient uptake. Superior treatment combination recorded higher stalk yield and seed index.