Oil accumulation kinetic along ripening in four olive cultivars varying for fruit size

To determine whether oil accumulation pattern is parallel to drupe olive (Olea europaea L) growth and if common climatic parameters may influence oil content we conducted an experiment in rainfed orchards with four olive cultivars, Amygdalolia, Arbequina, Lucques, and Olivière, differing by fruit size at maturity. Fruits were harvested weekly from July to November. They were counted and weighted before being crushed. Fat content was determined on dry matter using a Minispec RMN. Common climatic parameters were recorded. Variance analyses showed stage effects highly significant. Results showed three different patterns for fruit growth. Dry matter accumulated broadly similarly and the weekly rates were positively correlated with fruit size. Oil accumulation is mostly independent of climatic variation and probably depends on genetic programmes for each cultivar. We defined the main steps and events for olive fruit ripening according to recent knowledge on fruit development.