The Most Commercially Viable Olive Cultivars
is fortunate to have many of the world's most valuable olive
cultivars already on its shores. These have been selected and
imported from various olive growing regions of the world.
Although valuable cultivars are still being imported, Australian
growers can be confident with the cultivars already commercially
USED IN THE "CULTIVAR DESCRIPTIONS" SECTION
This is an area where problems are often encountered. Some sources name up to 100 cultivars in Australia at present, however, many of these names have never been heard of in other olive growing countries. So where have they come from? Are they new Australian cultivars?
In most instances, the cultivars have been brought to Australia by people immigrating from the Mediterranean regions. It may have been their favourite cultivar in their homeland so they decided to bring it to the new country with them. On arriving, many of the cultivars were given new names. This was usually done because either they forgot the real cultivar name or they wanted to name their olives after their hometown, a famous person or some sort of descriptive in their own language. With this in mind, it can be easily understood how a cultivar of name 'A' could actually be cultivar 'B' if it has been imported and renamed upon arrival. This factor makes correct identification of the lesser known cultivars very difficult.
The 'Other Names' sections in the following chapter consist of synonym names for the cultivar, agreed upon by the International Olive Oil Council and/or cultivar experts within the various countries of the Mediterranean. This is not a comprehensive list of synonyms, however it does cover the most popular synonyms for each of the cultivars.
Many believe that the only biological method able to 100% guarantee an olive's true cultivar origin is 'reading' the pattern of grooves on the seed of the fruit. Each cultivar family has its own 'fingerprint' on the seed. Unfortunately, there are very few people in the world skilled in seed identification. As such, the use of leaf shapes, sizes and colours, tree history, fruit and seed size, flesh texture and ratio, and oil contents etc. are usually used for cultivar identification.
Cultivar identification programs in the Mediterranean assess up to 55 different characteristics of each cultivar before publishing their results.
The possibility of identifying varietal "families" through the use of DNA is currently being done in a number of countries including Australia. However, this approach is only able to conclude that certain cultivars have similar DNA, it cannot ascertain the commercial viability of the cultivar or even guarantee that it is a specific cultivar without other aspects of the tree being taken into account.
the end of the day, the most important factor is that the cultivar,
whatever its origin or name, must produce commercial quantities
of high quality products on the grower's land.
section deals with the physical attributes of the cultivar. Aspects
such as fruit size, colour, weight and texture are discussed along
with the growth habits of the tree.
Throughout the olive growing regions of the world, single cultivars tend to be grown together in regions according to the climate and traditional industry established in the area. Small local nurseries have often promoted a personal favourite cultivar; or where they have good access to propagating material of a certain cultivar they may promote it above others which may even be more suitable for their region. Many, but not all cultivars have been tried in various climatic regions and it has finally been decided for some, that a given climatic zone is better for oil quality, crop yield or disease resistance than another zone.
However, it must be noted that many cultivar experts throughout the Mediterranean believe that cultivars which are currently most popular in a given climatic zone will not necessarily produce most effectively in that region. It is generally consented that most cultivars give heavier crops and good oil in warmer regions under irrigation. However, others say that the best oil is produced in areas where the trees are harshly treated with cold and dry conditions.
Until recently, it was generally believed that commercial olive groves would only crop between the latitudes of 30 and 45 degrees north and south of the equator. This was believed mainly because it was between these latitudes that the Mediterranean olive industry existed. As the Mediterranean has been the source of the majority of the world's olive products, these latitudes were accepted as the rule.
Australian terms, the 30th degree runs across just above Coffs
Harbour (NSW), just below Lake Eyre (SA) and just south of Geraldton
(WA). Traditionally, this would mean that only areas south of this
would be suitable for olive orchards. However, international plantings
over the past few decades have proven that many areas outside
of these latitudes have perfect climates for commercial olive production.
There are numerous regions which are nearer to the equator than
the 30th latitude, which due to their altitude or other geographic
aspect are very suitable for commercial olive orchards. Even within
the Mediterranean itself, there are many olive growing regions outside
of the traditional geographic limits. Due to the number of
areas within Australia that lie outside of the traditional
30-45 latitude and yet are suitable for commercial olive orchards,
we have chosen not to deal with the cultivars by their traditional
with any agricultural pursuit, the ultimate measure of a cultivar's
worth is whether or not it is commercially viable. This section
deals with the advantages and disadvantages of each of the cultivars
from a financial point of view. The current status of the cultivar
in other parts of the world has been supplied to give an indication
of the possible potential for it in Australia. Comments on the cultivars
by various people within the industry are also noted. Characteristics
which either promote or demerit the cultivar for different
aspects of the industry are mentioned.
"Pests and Disease"
Australia can thank its strict quarantine services for the general lack of serious olive diseases. The major olive diseases such as olive knot and olive fly have not been identified on our shores. Continued strict quarantine combined with the co-operation of people within the olive industry can keep our country clean well into the future.
There are six main diseases and insect pests which can effect olive orchards in Australia. These are peacock spot (Cycloconium oleaginum or Spilocaea oleaginea), olive lace bug, black olive scale (Saissetia oleae), verticillium wilt (Verticillium dahliae), olive moth (Prays Oleae or Margaronia unionalis) and anthracnose.
Research is currently being done into the identification of some 'grubs/maggots' which have been found in olives in some parts of Australia. It would appear that the problem is some form of a fly larvae but no results have been released as to its actual identification or whether it is related to the Dacus Oleae of other olive growing countries.
extent to which an orchard is effected by any of these problems
is naturally going to effect the commercial viability of the grove.
It is not within the range of this section to cover disease
and insect pest prevention, however their control is generally neither
difficult nor labour intensive.
In general, most researchers are now recommending that growers
plant at least three olive varieties in close proximity in their
groves to ensure some cross-pollination to improve fruit set.