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Margaret Edwards
J5 Olive Trees
After growing both J5 and Frantoio olive trees for 30 years, it is apparent that these varieties are not related, although the trees may appear similar in form.
It is difficult to trace the history of J5 accurately. In the 1950s the New Zealand government implemented a study into olive production and, as well as importing bare rooted olive trees for planting around the country, cuttings were taken from old, well-established olive trees. Cuttings taken from a tree in the Whangape area of Northland were given to Milton Johnson, a nurseryman, for propagation. The trees thrived and were named J5. The “mother” tree, which may have been planted by Frank Lisle on his property sometime in the early 1900s, is still alive.
J5 trees grow and produce well in the northern, warmer, more humid areas of New Zealand, possibly because the “mother” tree is growing on the edge of swampy ground. It is very unlikely that a Frantoio tree would tolerate and thrive with “wet feet.”
On examination, the pits from Frantoio and J5 are completely different, Frantoio pits being elliptical, slightly asymmetrical and rounded at the apex and base. The J5 pits are elongated, asymmetrical and pointed at the apex and base.
The oil yield is also different, Frantoio from my olive grove routinely has a return of oil of between 22% and 26% whilst J5 is normally in the 16% to 19% range.
However, the most significant factor is that the oil from these 2 varieties have completely different sensory profiles that bear no resemblance to each other. When one considers that the sensory profile of oil is set by the genetics of the variety, this surely becomes the factor that decides whether or not J5 and Frantoio are linked.