Round of Philadelphia

Among the large variety of olive trees in Calabria, it is worth mentioning the presence of a particularly valuable cultivar: the Tonda di Filadelfia.

Considered by many to be a clone of the Carolea, due to the similarity of the fruit, it was instead ascertained to be a real variety by genetic analyzes carried out at the Experimental Institute for Olive Growing in Rende (CS).

It is a plant with limited vegetative development, upright habit with medium thick foliage. The branches also ascending with short internodes, short and narrow leaves of an intense green color on the upper side, the lower one light green, lanceolate in shape with a rather irregular lamina with frequent curvatures of the apical part.

The spheroidal drupe is large in size 4 – 6 grams with an apex provided with a small umbo displaced with respect to the longitudinal axis, the lenticels are not very large but visible on the immature fruit, when fully ripe it has a vinous red colour. The yield in the sun on dry soil of 49.05% is reached in December, but already in November there are good yields of 44.1% always on dry soil. The kernel pulp ratio is 84.7%, the yield is high 24 – 25%.

He tends to alternate, but the productions over the years in office are quite good, very sensitive to mange and the oil fly.

Thanks to the analyzes carried out at the ISO of Rende (CS) for two years with three annual samplings, it is possible to state the following:

the acidity has always remained below 1%;
another interesting fact is the number of peroxides which fluctuated between 3 and 4 and only in one case did it reach 6.4;
the values ​​of rancimates were good, the resistance of the oil to rancidity, almost always higher than 10 hours;
the percentage of fresh oil fluctuated between 14 and 17% in relation to the harvesting period;
the data relating to the presence of oleic acid is also significant, very important for the quality of the oil since it influences its nutritional value, the average value recorded is 72% with peaks of 75%;
last but not least, the data relating to total polyphenols is reported, which were good until the end of October and then suddenly decreased, suggesting the optimal harvest time.
From these results it can be stated that the Tonda di Filadelfia is certainly a cultivar to be further spread even outside the current distribution area, both for its varietal characteristics (it is in fact a cultivar that can be easily mechanized due to the assurgence of the branches, for the good size of the fruit that could also be used for the table) and for the peculiarities of the oil obtained from it (in fact, according to the sensory analysis, the Tonda di Filadelfia oil was moderately fruity with a slight bitter and spicy taste).

However, further studies are necessary to limit its negative aspects, primarily the high susceptibility to mange and the alternation of production.