Ripening Document classification 1.3.5. Ripening Text Ripening is the process that precedes fruit senescence and its eventual decline. During ripening, significant metabolic and biochemical transformations alter the colour, composition, weight, oil content, respiration and fruit retention force. These changes are influenced by factors such as the cultivar, environmental conditions, agronomic practices like irrigation, and the fruit load. Table 1 shows a classification of ripening timing for cultivars in Spain, while Figure 5 shows the variations between years. For most cultivars, the colour of the fruit changes from intense green to yellowish-green, partially purple, purple, and eventually to violet-black, as shown in Figure 2. The timing of olive ripening is closely linked to the harvesting season, which in turn depends on the intended use of the olives. Olive cultivars suitable for "Sevillano style" table olives are usually harvested when they have reached a yellowish-green colour, while naturally black "Greek style" table olives are harvested when the fruit has turned completely black. When olive fruits are used for oil production, early harvesting tends to result in higher-quality oils due to their higher polyphenol content, among other characteristics. However, early harvesting is also associated with lower oil content and higher fruit retention force. Traditionally, farmers have prioritised maximum oil content and low fruit force retention, resulting in a preference for later harvesting. Nowadays, the balance between early harvest and optimum oil content is becoming increasingly important. Recent research suggests that the optimum date for oil content is mainly influenced by environmental conditions and is not necessarily related to the fruit colour. Therefore, to make the best decision on when to harvest, it is advisable to monitor the accumulation of oil content. Text Figure 3: Asynchronous flowering due to insufficient chilling causes the presence of different phenological stages within the same tree (from Medina-Alonso et al., 2020). Text Percentage of cultivars Figure 4: Evolution of timing of flowering for a group of 124 cultivars over 12 different years in the World Olive Germplasm Bank of Córdoba, Spain (in Barranco and Rallo, 2005). Percentage of cultivars Figure 5: Evolution of the timing of ripening for a group of 122 cultivars over 6 years in the World Olive Germplasm Bank of Córdoba, Spain (in Barranco and Rallo, 2005). Text Table 1: Classification of chilling requirements, flowering and date of budburst in the World Olive Germplasm Bank of Córdoba (Spain) and Marrakech (Morocco). Cultivar Chilling requirement assessment Budburst Flowering Ripening Empirical1 Modelling2 Marrakech (Morocco) Córdoba3 (Spain) Arauco Mid-Late Arbequina Low 20 Feb Early-Mid Early Late Arbosana Medium Barnea Late Beladi Medium 26 Feb Mid-Late Mid Late Buga Low 20 Feb Late Carolea Medium 26 Feb Early Chalkidikis Low 20 Feb Early Chemlali Sfax Extra Late Chetoui Medium Low 20 Feb Early-Mid Late Coratina Low 21 Feb Early Cordovil de Serpa Medium 20 Feb Late Late Late Cornicabra Medium 26 Feb Early Crnica Low 20 Feb Late Frantoio High Medium 26 Feb Mid-Late Mid Mid Galega Vulgar Low 20 Feb Late Gemlik Medium 29 Feb Mid-Late Extra Late Early Gordal Sevillana Low Medium 25 Feb Mid-Late Mid Hojiblanca Medium Medium 21 Feb Mid-Late Mid Late Istarska Bjelica Mid-Late Kalamon Late Early Kato Drys Medium 27 Feb Late Koroneiki Medium Medium 28 Feb Early Early Lastovka Medium 20 Feb Early Early Late Leccino High Highest 6 Mar Late Mid Early Manzanilla Cacereña Medium 20 Feb Early-Mid Early Mid Manzanilla de Sevilla Medium 21 Feb Early-Mid Mid Mid Maurino Medium 21 Feb Mid-Late Late Early Meski Early-Mid Early Nocellara del Belıce Medium 26 Feb Mid Peranzana = Bosana Medium 21 Feb Mid Picholine du Languedoc Medium 20 Feb Mid Picholine Marrocaine Medium 27 Feb Early-Mid Mid Late Picual High Medium 28 Feb Late Late Late Salonenque Medium 21 Feb Early Early Early Sourı or Soranı Early-Mid Tsounati = Mastoidis High Medium 21 Feb Early 1: Chilling requirement assessment by leafy explant cutting method (Ramos et al., 2018; Rubio-Valdes et al., 2023) in Córdoba (data not published). 2: Chilling requirement assessment by modelling method in Marrakech (Morocco). Four groups for chilling requirements (Low, Medium, High, and Highest), according to Abou-Saaid et al., 2022.3: Four groups for flowering time in Córdoba (Early, Early-Mid, Mid-Late, and Late), adapted from 10 original groups in Belaj et al., 2020.4: Four groups for flowering time in Marrakech (Early, Mid, Late, and Extra Late) according to Abou-Saaid et al., 2022.5: Three groups for fruit ripening time in Córdoba (Early, Mid, and Late), adapted from 10 original groups in Belaj et al., 2020. Text References Abou-Saaid, O.; Yaacoubi, A.E.; Moukhli, A.; Bakkali, A.E.; Oulbi, S.; Delalande, M.; Farrera, I.; Kelner, J.-J.; Lochon-Menseau, S.; Modafar, C.E.; Zaher, H.; Khadari, B. Statistical Approach to Assess Chill and Heat Requirements of Olive Tree Based on Flowering Date and Temperatures Data: Towards Selection of Adapted Cultivars to Global Warming. Agronomy 2022, 12, 2975. Barranco, D., Rallo, L., 2005. Épocas de floración y maduración pp. 281-292. En: Variedades de olivo en España (Libro II. Variabilidad y selección). L. Rallo, D. Barranco, J. M. Caballero Carmen del Río, A. Martín, Joan Tous e Isabel Trujillo. (Eds.). Junta de Andalucía, MAPA, Mundi-Prensa. Madrid. Belaj, A., de la Rosa, R., León, L., Gabaldón-Leal, C., Santos, C., Porras, R., de la Cruz-Blanco, M., & Lorite, I. J. (2020). Phenological diversity in a World Olive Germplasm Bank: Potential use for breeding programs and climate change studies. Spanish Journal of Agricultural Research, 18(1), Issue 1, e0701. Medina-Alonso MG, Navas JF, Cabezas JM, Weiland CM, Ríos-Mesa D, Lorite IJ, León L, de la Rosa R (2020) Differences on flowering phenology under Mediterranean and Subtropical environments for two representative olive cultivars. Environmental and Experimental Botany 180:104239. Ramos, A., Rapoport, H. F., Cabello, D., & Rallo, L. (2018). Chilling accumulation, dormancy release temperature, and the role of leaves in olive reproductive budburst: Evaluation using shoot explants. Scientia Horticulturae, 231, 241–252. https://doi.org/10.1016/j.scienta.2017.11.003. Rapoport, H., Moreno-Alías, I. 2017. Botánica y morfología. En: Barranco, D., Fernández-Escobar, R., Rallo, L., eds. El cultivo del olivo. 7ª Ed. Mundi-Prensa. Madrid. 37-43. Rubio-Valdés, G., Cabello, D., Rallo, L., & Rapoport, H. F. (2022). Bud Dormancy Release Dynamics in the Olive Tree and Validation of the Use of Explants to Determine Chilling Requirement Fulfillment. SSRN Electronic Journal. https://doi.org/10.2139/ssrn.4169505. Sanz-Cortés F, Martínez-Calvo J, Badenes ML, Bleiholder H, Hack H, Llácer G, Meier U, 2002. Phenological growth stages of olive trees (Olea europaea). Ann Appl Biol 140: 151-157.