Effect of boron on kernel and leaf mineral contents in hazelnut trees

The effect of boron application in hazelnut quality and production are not clear. Some authors reported that fruit yield and nut quality may increase with boron application whereas others did not find any effect. The purpose of this research was to study possible effects of boron on mineral contents of kernel and leaves and on nut production on hazelnut cultivars grown in Tarragona, Spain. A two year experiment (1992-93) was conducted in two drip irrigated orchards, one with cultivar "Negret" located in La Selva and the second in Mas Bove, with "Pauetet" hazelnut. Four boron treatments included an untreated control, two levels of foliar spray (300 and 600 mg B. liter(-1)) using about two liters per tree and a soil treatment of 12 g B per tree were tested. Treatments had 5 replications for "Negret" and 4 for "Pauetet. Boron treatment significantly affected boron kernel and boron foliar contents in both cultivars. Boron content in kernels ranged from 10 to 16 (mu g.g(-1) and boron levels in foliar samples, obtained at the end of july, were from 19 to 140 (mu g.g(-1). Soil application produced the upper boron levels in nuts and in leaves. Results show that B application did not increase fruit production. Nut yield in "Negret" cultivar ranged from 2630 kg. ha(-1) to 1498 kg.ha(-1) in 1992 and 1993 respectively, whereas in "Pauetet" the yield was 2184 kg.ha(-1) in 1992 and only 783 kg.ha(-1) in 1993.