Determination of Phenotypic Diversity and Effective Temperature Sum Times in Some Olive (Olea europaea L.) Varieties by Using Phenological Stages with Multivariate Analysis

In the research, a total of 12 olive varieties, three foreigner and nine local, were used. In 2021, the beginning of inflorescence was determined between the 27 March (‘Memecik’) and 19 April (‘Domat’), while the beginning of black (harvest) maturity was determined between 30 September (‘Gemlik-21’) and 28 November (‘Domat’). In 2022, the beginning of inflorescence was determined between 2 April (‘Memecik’) and 17 April (‘Domat’), while the beginning of black (harvest) maturity was determined between 4 October (‘Ayvalık’) and 30 November (‘Domat’). In 2021, the effective temperature total duration between the beginning of inflorescence and the beginning of black (harvest) maturity varied between 2300 (‘Edincik Su’) and 2736 degree-days (‘As Topakaşı’), while in 2022 this period varied between 2403 (‘Ayvalık’) and 2685 degree-days (‘As Topakaşı’). In 2021, the passing time between the beginning of inflorescence and the beginning of black (harvest) maturity was determined to vary between 182 (‘Gemlik-21’) and 224 days (‘Domat’), while in 2022, this period was determined to vary between 183 (‘Ayvalık’) and 228 days (‘Domat’). According to the correlation analysis, a positive correlation was found between the beginning of inflorescence and the beginning of black (harvest) maturity effective temperature sum and the beginning of inflorescence and the beginning of black (harvest) maturity passing time (r = 0.91, p < 0.001); the beginning of flowering to the beginning of black (harvest) maturity effective temperature sum and beginning of flowering to the beginning of black (harvest) maturity passing time (r = 0.92, p < 0.001). According to principal component analysis, the first three principal components account for 78.50% of total variation. This study, which will be recorded as the first detailed research in the literature in terms of olive cultivation, will greatly assist those concerned in planning the basin-based plant production model.