Potential use in olive nurseries of olive cake and compost from animal manure or urban rubbish.

The influence of light availability on olive fruit development, oil accumulation and the qualitative characteristics of the oil were studied. The trial was carried out in central Italy, on non-irrigated trees of cultivars 'Frantoio' and 'Leccino'. In October and November, samples of olives grown under conditions of low or high light availability (about 400 and 1100 ?mol of photons m-2 s-1) were collected and analysed. Fruit ripening was slightly affected by high availability of light (higher pigmentation and detachment force and lower pulp consistency). Olives grown under well lighted conditions, with respect to those grown at low light intensity, were heavier, had a higher percentage of oil and a lower water content. The pulp/pit ratio was not affected by light intensity. The oils extracted from olives grown under high light conditions had a higher polyphenol content and better sensorial characteristics than those obtained from olives grown at low light intensity. The acidity and peroxide number were not affected by the light conditions. The results highlight the importance of ensuring good, uniform illumination of the entire crown by making optimal choices at the moment of the olive orchard establishment and rationalizing all techniques that affect light availability at the crown level (planting area exposition, training system and spacing, pruning intensity, etc.).