Zinc application enhances yield and alters micronutrients concentration in pigeonpea (Cajanus cajan L. Millsp.)

Abstract

Zinc (Zn) deficiency prevails in different soils and crops of the world. Soil Zn deficiency adversely affects growth, yield and micronutrients (Zn, copper (Cu), iron (Fe) and manganese (Mn)) concentration in different crops including pigeonpea (Cajanus cajan L. Millsp.), a protein rich legume crop grown consumed in different parts of the world. Therefore, we carried out a 2-years field experiment on a Zn-deficient Vertisol with 20 different pigeonpea genotypes and 3 levels of Zn treatments in a split-plot design with 3 replications, to study the effect of Zn application on yield, micronutrients concentration and uptake by pigeonpea genotypes. The 3 levels of Zn treatments were no Zn (no Zn fertilizer was applied), soil Zn (20 kg Zn ha−1) and soil + foliar Zn. Compared to no Zn application, soil and soil + foliar application of Zn enhanced mean grain yield by 15 and 24%, stover yield by 13 and 29% and total biomass yield of pigeonpea genotypes by 13 and 29%, respectively. Soil + foliar application of Zn significantly increased mean grain Zn concentration by 33% compared to no Zn application. Soil and soil + foliar Zn application led to reduction in mean grain Cu concentration by 9 and 10%, respectively, and did not significantly increase or decrease grain Fe and Mn concentration. Soil and soil + foliar application of Zn significantly increased mean grain Zn, Fe and Mn uptake by pigeonpea genotypes compared to no Zn application. Soil + foliar application of Zn had significantly higher mean grain Zn, Fe and Mn uptake compared to soil Zn application. The grain, stover and total biomass yield, micronutrients concentration in grain and stover and micronutrients uptake by the genotypes were different under various treatments. The genotypes ICPL 87119, BDN 2, JKM 7, Virsa Arhar 1, DT 23 and AAUT 2007–10 under soil application of Zn and ICPL 87119, BDN 2, JKM 7 and Virsa Arhar 1 under soil + foliar application of Zn were found promising for cultivation to obtain higher grain yield and micronutrients uptake.