Effect of different levels of zinc on zinc efficiency for maize genotypes under calcareous soil

Abstract

Twelve maize genotypes viz. Four composites (Laxmi, Swan, Devki and Hemant), four quality protein maize (Shaktiman-1, Shaktiman-2, Shaktiman-3, and Shaktiman-5) and four hybrids (Raja 909, NK 6607, Rasitopless and Rasi 3022) were tested for their response and efficiency to zinc fertilization at Dr. Rajendra Prasad Central Agricultural University Pusa (Samastipur) Bihar. The genotypes were not equally responsive to zinc application. Except composite genotyped all other genotypes (Hybrid and Quality protein maize) showed higher response to zinc application. Among the hybrids the Rasitopless had the highest response followed by Raja 909, NK 6607 and Rasi 3022, the later two having identical responses. Comparing the Quality protein maize their response can be ranked as Shaktiman-5> Shaktiman-1> Shaktiman-3> and Shaktiman-2. The relative grain yield i.e zinc efficiency index varied from 92.5 to 75.5% and relative grain zinc uptake i.e zinc efficiency varied from 77.4 to 44.8% among the genotypes. On the basis of Zinc efficiency, genotypes were classified into efficient and nonresponsive (Raja 909, NK 6607, Rasitopless, Rasi 3022 and Shaktiman-3), efficient and responsive (Shaktiman-1 and Shaktiman-2), inefficient and nonresponsive (Shaktiman-5) and inefficient and responsive (Laxmi, Swan, Devki and Hemant). From a practical point of view genotypes that produce high grain yield at low level of zinc and respond well to zinc additions are the most desirable because they able to express their high yield potential in a wide range of zinc availability.