EFFECTS OF CHEMICAL FRUIT THINNING ON FRUIT YIELD AND QUALITY IN ‘GEMLIK’ OLIVE (OLEA EUROPAEA L.)

Abstract

In recent years, a large amount of ‘Gemlik’ olive variety started to be grown in Aegean Region. ‘Gemlik’ is a black table variety, but it is processed to oil in many areas. Since ‘Gemlik’ olive is a double purpose variety, chemical fruit thinning may be useful to control alternate bearing and standardization of the fruit size. In this study, clearing out the effects of chemical fruit thinning by potassium salt of naphtaleneacetic acid (NAA-K), on fruit yield and quality in ‘Gemlik’, which is one of the important olive cultivar of Turkey, was aimed. Olive trees treated with 180 ppm NAA-K gave 26.6 and 53.1 kg fruit/tree in “off” and “on” years respectively, while the untreated trees gave only 13.6 and 17.8 kg fruit/tree. 180 ppm NAA also gave rise to decreases in figures of most variables and delayed the fruit maturity in both thinning years. In “on” year, 120 ppm NAA increased the size (fruit/kg), and dimensions (width and length) of olive fruits together with 100 ppm. In “on” years, NAA treatments at 100–120 ppm might be useful to increase the fruit dimensions in ‘Gemlik’ olive.