Table 3. Average number of days to callus initiation.

Explant	Control	ZnO-NPs 10 mg/L	ZnO-NPs 20 mg/L	ZnO-NPs 30 mg/L	ZnO-NPs 40 mg/L	ZnO-NPs (50 mg/L)
Seeds	29±1.45	27±3.22	20±2.15	20±0.01	32±0.76	_______
Internodes	23±1.05	23±0.45	17±2.75	15±1.85	29±0.98	33±1.55