Chemlali Sfax Download sheet Fruit Denomination and synonyms Origin and diffusion Originated from Sfax region in the centre of Tunisia, it is cultivated throughout the centre and the south. Almost, this variety occupied 56% of the olive areas and 69% of the total trees in Tunisia (CCIS, 2013). Thus, Chemlali Sfax is considered the main oil variety in Tunisia. Fathi Ben AmarFathi Ben AmarFathi Ben Amar Purpose Oil Morphological characterisation Tree Vigour Strong Growth habit Upright Canopy density Dense Fruit Weight Low Radio length/width in position A Moderately elongated Over colour at full maturity Black Symmetry in position A Weakly asymmetric Shape of apex in position A Obtuse Nipple Absent or weak Shape of base in position A Truncate Leaf Length Medium Width Medium Radio length/width Moderately elongated Curvature of longitudinal axis Straight Stone Radio length/width Moderately elongated Weight Low Shape of apex in position A Acute Symmetry in position A Weakly asymmetric Symmetry in position B Symmetric Shape of base in position A Rounded Number of grooves on basal end Between 7 and 10 Distribution of grooves on basal end Evenly distributed Mucron Present Rugosity of surface Medium Molecular characterisation (SSRs) UDO-43 DCA3 DCA9 DCA16 GAPU-101 175/214 229/237 192/192 122/173 191/205 Agronomic characterisation and commercial considerations Chemlali Sfax is well adapted to different environments in Tunisia and different cultural modes (Trigui and Msallem, 2002) especially in salty and arid conditions (Ben Ahmed et al. 2008, 2009). Oil quality degradation is observed in saharian climate: high temperature, high light intensity and low rainfall (Dridi et al. 2016). It has an early maturity (November), medium propagation rate by cuttings, high fat rate reaching 29 % and autofertile behaviour (Grati-Kamoun and Khlif, 2001). This variety was famous by the low density of plantation (17 trees/ha) in rainfed conditions of the centre-south of Tunisia and is still the symbol of the olive forest of Sfax with 24m/24m spacing (CCIS, 2013). It’s characterised by high productivity and alternate bearing high in rainfed conditions and medium in irrigated conditions (Elloumi et al. 2017). The acid composition of its oil is characterised by low oleic acid level and high palmitic acid level (Grati-Kamoun et Khlif, 2001). A maximum of 59% level for oleic acid was reported by Ben Amar et al. (2021). At early maturity, the oil of Chemlali Sfax is with intense fruity aroma, slightly bitter and spicy taste (Grati-Kamoun and Khlif, 2001).To improve the acid composition, a genetic improvement program was initiated in 1990th and recently five new varieties were released in the Tunisian varietal catalogue (Guellaoui et al. 2019).Chemlali Sfax was found to be extremely susceptible to Verticillium dahliae (Yaacoub et al. 2017) and tolerant to draught and moderately tolerant to salinity (Elloumi et al. 2022). This variety is moderately tolerant to olive mite, susceptible to olive fly ant highly susceptible to psyllid (Mraicha, 2012; Dibou, 2012). Fathi Ben Amar