Effects of Chemical Fruit Thinning on Oil Yield and Quality in ‘Gemlik’ Olive (Olea europaea L.)

Abstract

‘Gemlik’ olive variety started to be grown in many areas of Turkey in recent years. ‘Gemlik’ is mainly a black table variety, but it is processed to oil in many areas. So chemical fruit thinning may be useful to control alternate bearing and standardization of the fruit and consequently the oil quality. In this work, predicting the effects of chemical fruit thinning by potassium salt of naphtaleneacetic acid (NAA-K) on oil yield and quality in ‘Gemlik’, which is one of the prominent olive variety of Turkey was aimed. Results showed that NAA applications decreased the oil acidity levels in the first year (off year). In the second year (on year), NAA sprayings at 100 and 120 ppm increased the oil acidity up to 1.75 % while 150 ppm decreased the acidity value to 0.36 %. 180 ppm NAA significantly augmented the oil content of olive fruits particularly in “on year” and gave rise to 22 and 48 % increments in oil rates successively on fresh and dry matter basis compared to control.