Zinc seed treatments improve productivity, quality and grain biofortification of desi and kabuli chickpea (Cicer arietinum)

Chickpea (Cicer arietinum L.) is a leading food legume primarily grown in marginal areas and consumed all over the world. However, its production is limited owing to zinc (Zn) deficiency in many chickpea-based cropping systems. This study was conducted over two years to evaluate the effect of Zn application through seed treatments on productivity and grain Zn biofortification of kabuli and desi chickpea types in Punjab, Pakistan. Pre-optimised doses of Zn were applied as (i) seed priming (0.001 m Zn) and (ii) seed coating (5 mg Zn kg-1 seed), using ZnSO4.7H2O (33% Zn). Hydropriming (soaking in water) and non-primed dry seeds were used as control treatments. Zinc seed treatments significantly improved leghemoglobin contents, nodulation, grain yield, grain Zn yield, grain bioavailable Zn, grain minerals and grain Zn concentration compared with control treatments in both chickpea types. During both years, kabuli chickpea receiving Zn seed coating had higher grain yield (2.22 and 2.73 t ha-1) and grain Zn yield (103 and 129 g ha-1) than kabuli receiving other treatments. Likewise, during both study years, maximum grain bioavailable Zn (4.58 and 4.55 mg Zn day-1) was recorded with Zn seed coating in both chickpea types. Kabuli chickpea had more grain bioavailable Zn than desi. With regard to seed treatments, desi chickpea was more responsive to Zn osmopriming, whereas kabuli was more responsive to Zn seed coating. In conclusion, Zn seed treatments, as seed priming and seed coating, are effective methods for improving the productivity, grain quality and Zn biofortification of both desi and kabuli chickpea.