Response of field-grown barley cultivars grown on zinc-deficient soil to zinc application

Field experiments were carried out to study the response of barley varieties (Hordeum vulgare L. cvs. Tokak-157/137, Erginel-90, Obruk-86, Bulbul-89, Cumhuriyet-50, and Kiral-97) to increasing applications of zinc (Zn) (Control, 9, 18, and 27 kg Zn ha(-1)) in Zn-deficient calcareous soils (DTPA-Zn = 0.26 mg kg(-1) soil). Relative increases in grain yield as a result of Zn applications over control ranged from 16% to 29% in the 1994-95 and 1995-96 growing seasons, respectively. However, all Zn doses were placed in the same yield group. In the control plants, Zn concentrations of the leaves and grains were 10.55 mg kg(-1) and 9.95 mg kg(-1), respectively, as the mean of all varieties. These Zn concentrations were below the critical Zn concentration which was reported as 10-15 mg kg(-1). Zinc concentrations of the leaves and grains were increased by Zn fertilization and relative increases were 185% (30.05 mg kg(-1)) and 122% (20.00 mg kg(-1)), respectively. In spite of variety x zinc, interaction was not significant, "Erginel-90" "Kiral-97" and "Cumhuriyet-50" varieties showed the highest grain yield increases by Zn application over the control. Thus, these varieties were determined as more susceptible varieties to Zn deficiency. Also, the yield components showed marked increases as a result of Zn application. Relative increases in plant height, grain number per spike, spike number per square meter with Zn application over the control were 28%, 31%, and 35% in 1994-95 and 20%, 22%, and 18% in 1995-96, respectively. The results showed that Zn deficiency is a critical nutritional problem limiting barley production in the Konya Province of Central Anatolia. The results also showed that Zn concentrations in leaves and grains were below the critical Zn concentration, and significant increases in grain yield, Zn concentration of leaves and grains and some yield components as a result of Zn application were found.