EFFECTS OF IRON CHELATE LEVELS AND TYPES ON YIELD AND GRAIN IRON CONCENTRATION OF TEFF [(Eragrostis tef (Zucc.) Trotter] IN TIGRAY SOILS, ETHIOPIA

Abstract

Iron deficiency was reported in Tigray in soils with relatively higher soil pH (>7.3), that possibly limit productivity of teff. There are limited researches on Fe nutrition to teff. To evaluate the effects of Fe levels and Fe chelate types on yield and grain Fe concentration of teff, greenhouse pot experiment was conducted in five high pH and Fe deficient soils collected from Leptic Regosols, Vertic Cambisols, Luvisols and Cambisols. The experiment was conducted in a factorial (Fe-rates x Fe-chelate types x soils) completely randomized design with three replications. Three supplemental Fe levels of 0, 2.5 and 5 kg ha-1 and three Fe chelate types of Fe-HBED (6% Fe of which 6.0% ortho-ortho Fe), Fe-EDDHA1 (6% Fe of which 4.0% ortho-ortho Fe) and Fe-EDDHA2 (7% Fe of which 1.5% ortho-ortho Fe) were used. Application of Fe at a rate of 2.5 kg ha-1 significantly increased teff biomass yield in all studied soils with a mean yield of 47.33 g per 0.049 m2 pot while it was 44 g per 0.049 m2 pot in the control. Increase in teff biomass yield was found to be consistent with the decrease in initial Fe content. Among the Fe chelate types and levels, Fe-EDDHA1 at application rate of 2.5 kg ha-1 improved teff grain yield and grain Fe concentration by 13.6 and 37%, respectively, over the control. The findings indicated that application of appropriate Fe chelate fertilizer is important to sustain sufficient yield and nutrition of teff in high pH and Fe deficient soils.