Yield and mineral composition of grapevine (Vitis vinifera L. cv. Karaerik) as affected by boron management

Boron (B) deficiency is widespread in the northeastern Anatolian region of Turkey. This could impact the production and quality of grapevine (Vitis vinifera L. cv. Karaerik). A field experiment was conducted for determining the optimum economic B rate (OEBR), critical soil test, and tissue B values for yield and quality response of grapevine to B fertilizer application method (foliar and soil) at 5 doses (0, 1, 3, 9, and 12 kg B/ha) for 2 years. OEBR of foliar and soil application ranged from 6.4 to 8.5 kg B/ha with an average yield of 20.2-12.8 t/ha, respectively. The average soil B content at the OEBR was 0.32-2.52 mg/kg. Leaf tissue B content amounted to 98.9 and 64.4 mg/kg, and berry B content amounted to 21.4 and 12.9 mg/kg for foliar and soil application methods, respectively. Independently of application method, B application increased tissue N, Ca, Mg, P, K, and Zn, yet decreased Fe, Mn, and Cu content. We concluded that a B addition of 6.4 kg/ha for foliar application and 8.5 kg/ha for soil application is sufficient to elevate soil B to nondeficient levels.