Agronomic Bio-fortification of Zinc in Sorghum (Sorghum bicolor L.) Genotypes

Abstract

A field experiment was conducted to assess the zinc (Zn) content in sorghum grain, leaves, stem and root with soil and foliar application of Zn. Significantly highest grain (3.25 t ha−1), leaves (3.87 t ha−1), stem (7.92 t ha−1) and root (2.69 t ha−1) yield was recorded with soil application of 5 kg Zn ha−1 through ZnSO4 along with two foliar sprays @ 0.5% ZnSO4 before flowering and at dough stage as compared to soil application of 5 kg Zn ha−1 alone or control. Among the eight sorghum genotypes, the genotype CSH-35 recorded significantly highest grain yield (3.99 t ha−1) as compared to the PVK-809, CSV-20, AKSV-181, AKSV-161, AKSV-313, AKSV-314, AKSV-318 genotypes. Highest Zn content was recorded in sorghum grain (43.5 mg kg−1), leaves (19.7 mg kg−1), stem (23.6 mg kg−1) and root (42.4 mg kg−1) consequent to soil application of 5 kg Zn ha−1 through ZnSO4 along with two foliar sprays before flowering and at dough stage. Soil plus foliar application of Zn increased the Zn uptake by grain, leaves, stem and root of sorghum. The highest agronomic efficiency (AEZn) was recorded with the soil application of 5 kg Zn ha−1 through ZnSO4, followed by soil application of 5 kg Zn ha−1 and two foliar application of ZnSO4 @ 0.5%, but the apparent recovery efficiency (REZn) of Zn was highest in the latter case. The REZn increased with an increase in Zn levels, but AEZn decreased with the increase in Zn levels.