Root Dipping, Foliar and Soil Application of Zinc Increase Growth, Yields, and Grain Zinc in Rice (Oryza sativa L.) Grown in Moderate Zinc Soil of Inceptisol Order

Abstract

ABSTRACT Zinc (Zn) fertilization not only increased yield of rice but also serves as an economical source of Zn to fight Zn deficiency problems in humans and cattle. A pot experiment was conducted during 2016 (kharif) to study the response of different methods of Zn application on growth, yield, and zinc concentration of rice. Treatments consisted of T1 – without fertilizers (WF); T2 – recommended dose of fertilizer (RDF); T3 – RDF+soil application of 5.0 kg Zn ha−1 (SA5); T4 – RDF + soil application of 7.5 kg Zn ha−1 (SA7.5); T5 – RDF + soil application of 10 kg Zn ha−1 (SA10); T6 – RDF + root dipping in 2% ZnO (RD); T7 – RDF + SA5 + RD; T8 – RDF + foliar application of 0.5% ZnSO4 at tillering and flowering stage (2FA); T9 – RDF + foliar application of 0.5% ZnSO4 at tillering, flowering, and milking stage (3FA); T10 – RDF + SA5 + foliar application of 0.5% ZnSO4 at tillering stage (1FA); T11 – RDF + SA5 + 2FA; and T12 – RDF + SA5 + 3FA. Significantly higher grain and straw yield was obtained in T7 and T6, with a corresponding increase of 17.6 and 30.0% over RDF. Conjoint application of Zn (T7) increased the Zn concentration in grain and straw as compared to RDF, but FA of Zn was more effective than SA. Higher doses of Zn applied increased Zn and manganese (Mn), but decreased the concentration of iron (Fe) and copper (Cu) in grain. Application of 10 kg Zn ha−1 (T5) significantly increased (1.78 folds) the DTPA extractable Zn content in postharvest soil over RDF.