Seed priming and soil application of Zinc improved yield and shoot Zn concentration of corn (Zea mays L.)

Background Zinc (Zn) deficiency is a serious issue which negatively affects yield and quality of different crops. Various crop species and cultivars exhibit varying responses to Zn application with diverse techniques. Improved seed germination and subsequent seedling establishment in corn has been observed by Zn application via seed priming. This improvement in early growth stages ultimately leads to higher yields of grains enriched with Zn. Methods The current greenhouse study evaluated the impact of ZnSO4 (5 mM solution) seed priming durations (i.e., 1, 10, 30 and 60 min) on dry matter yield and shoot Zn concentration on corn (Zea mays L.) grown on different soil types (Zn-deficit and Zn-sufficient) (soil supplementation with Zn) soils. Unprimed seeds were taken as control for comparison. Chlorophyll index, dry matter yield and shoot Zn concentration were recorded at 20 and 25 days after emergence. Results Seed priming with ZnSO4 for 60 min significantly improved chlorophyll index on Zn-deficit (1.44 %–5.72 %), and Zn-sufficient (2.28 %–2.97 %) soil. Similarly, dry matter yield was improved by 32.45 %–58.20 % on Zn-deficit and 0–3.79 % on Zn-sufficient soil by the seeds primed for 60 min compared to unprimed seeds. Likewise, ZnSO4 seed priming for 60 min improved shoot Zn concentration by 17.21 %–32.83 %, and 0 %–11.85 % on Zn-deficit and Zn-sufficient soils, respectively. The improvements in the recorded traits were directly proportional to priming duration. A higher improvement in the recorded traits was recorded on Zn-deficit soil than Zn-sufficient soil. However, the values of the traits on Zn-deficit soil were ∼50 % less than those observed from Zn-sufficient soil. Conclusion Growth and Zn accumulation in corn was increased with increasing priming duration. However, seed priming alone was insufficient to improve shoot Zn concentration. This might be attributed to low priming duration. Therefore, future studies with longer priming duration are needed to reach sound conclusions. Nonetheless, both seed priming and soil application of Zn are required to improve growth and shoot Zn concentration of corn on Zn-deficit soils.