Response of Olive Trees to Different Boron Application in Izmir and Mugla Province of Turkey

Abstract

ABSTRACT This study was conducted to determine the effect of boron (B) applications on the olive yield and quality in Izmir and Mugla province of Turkey. For this purpose, 254 soil and leaf samples were taken simultaneously and analyzed. After the analysis six locations with different B levels were chosen. The soil-leaf content was 0.83–12.03 mg kg−1 in Milas, 0.85–14.39 mg kg−1 in Seydikemer; 0.36–16.99 mg kg−1 in Dikili; 0.23–16.80 mg kg−1 in Odemis; 0.65–16.69 mg kg−1 in Urla and 1.40–17.29 mg kg−1 in Bergama, respectively. The field trials were carried out in five replicates according to the random blocks, four application types (control (C), soil (S), foliar (F), soil + foliar (S + F)). S applications (0 g B tree−1; 4000 g B ha−1) were done before the shoot activity, F application (0 mg B L−1; 300 mg B L−1) was done after harvest, before flowering, after fruit set. The F application increased yield 47% at Bergama and 75% at Odemis location. In other locations, applications are not effective statistically, but when compared with the C group, the yield values increase with F and S + F applications. It is thought that this increase of yield is very important for olive plants and it was related to the B contents of the leaves and fruits. B applications increased B content of leaves and fruits, and affected the dry matter and oil content of fruits. The results suggest that foliar B applications are effective in increasing olive yield, and application should be done at three different times after harvest, before flowering and after fruit set. Further studies on B should take the cultivar into account for a faster progress in the knowledge on B mobility in olive.