Outlined below are some questions and answers about our industry.

Q. What is the cost per hectare to plant a olive grove?
A. On well-drained arable land, and with your own labour and equipment it currently costs around $9,000 per hectare. This includes irrigation lines and sprinklers, but excludes fences, water supply, shelter belts etc.

Q. What is the expected yield of fruit per tree?
A. This depends on the olive variety planted and the local micro-climate. An expected yield from variety Frantoio is around 20 kg at year 7.

Q. How much olive oil would you expect to obtain from Tasmanian olives?
A. This depends on the olive variety and grove location. The ripe fruit from a mature and established Frantoio olive tree should yield 15-20% of oil. However, the anti-oxidant polyphenols reach a maximum proportion some weeks prior to maximum oil yield, then dramatically reduce as the oil yield increases.  If growers prefer to enhance the taste and nutritional qualities of their oil they should harvest when polyphenol content is high.

Q. When does an olive tree yield fruit?
A. Usually in year 3,  but commercial quantities usually occur in year 5.

Q. What is the difference between black and green olives?
A. As an olive ripens it changes colour from green-yellow-purple-black. Black olives usually contain more oil, however the nutritional quality declines as the fruit over-ripens. The amount of highly nutritious polyphenols, many of which are anti-oxidants, peak 2-3 weeks before the maximum oil yield is attained in the fruit during ripening.

Q. What age should a tree be before you allow fruit to set?
A. Any age, but you can improve vegetative growth if you follow the following regime.               All flowers are removed until year 3
    Year 4 - remove 3/4 of the flowers
    Year 5 - remove 1/2 of the flowers
    Year 6 - remove 1/4 of the flowers
    Year 7 - full production                                                                                                

This procedure is extremely arduous and many growers do not consider it to be worthwhile.

Q. What is the standard no. trees for plantings per h/a? 
A. The traditional planting spacing of 8 metre wide rows and trees planted 5 metres apart will give 250 trees per hectare. Closer in-row spacing less than 5 metres will give difficulty with fruit harvesting catching frames. Narrower row widths will restrict access to large mechanical harvesting machines. Hedgerow planting with 2.5m tree spacing will give increased yield per hectare during the early years of grove establishment, but restriction to sunlight and air may induce disease problems. Traditional spacing should give an equivalent yield from around year 10.

Q. Does an olive tree require irrigation?                      

A. Yes. You will get an increased fruit set if you irrigate before and through the flowering period. If the tree is stressed through lack of water it will focus it’s resources to support leaves and roots.

 
Q. Can all  olive trees be used for both oil and table products?
A.  All olives can be processed for table fruit, however not all fruit can be processed for oil.  Generally speaking there are 3 types of olive trees: -

Q. Where are olives planted in Tasmania?  

A. Subject to soil type and drainage, cool climate varieties will grow in most areas of Tasmania. However, as ripening fruit is damaged by frost and young trees can have their bark split by sub-zero temperatures, most inland commercial groves are planted in areas below an altitude of 120 metres above sea-level. Currently the majority of olive plantings are in the South East and East coast areas.

If you are in an area which receives frosts from mid May onwards, it is recommended that you maximise sunlight to ripen your fruit early by planting on land with a Northerly aspect; use 7m x 5m or 8m x 5m planting spaces, arrange rows on a North– South axis, and prune your trees to an open-vase shape to allow light into the centre of the tree.

Q. Do same variety olive trees grow as quickly in Tasmania as they do in warmer areas of mainland Australia.                                   

A. No!  We have slower growth rate, due to the reduced number of warm days when the tree is in it’s vegetative growth period. However, as we have a longer cool or dormancy period our olive oil has been discovered to have higher levels of tocopherols and oleic acid, the main mono-unsaturated fat in olive oil. A fatty acid oil profile study in 2005, discovered that most of our oleic acid levels were over 80%. Some even more nutritious oils were found to have values higher than 83%, which is the determined IOOC maximum qualifier for extra virgin olive oil.

From a fatty acid profile perspective, our oil is more nutritious than that produced in warmer climates. The Tuscan area of Italy is renowned for producing premium olive oil. It is interesting to note that Tasmania has a similar Southern latitude to the Northern hemisphere’s Tuscan region.

Q. What variety of olives should I plant in Tasmania.                         

A. Most growers with established groves are getting commercial yields from Frantoio, Correggiola Mission, Barnea*, Verdale, and Manzanillo. 

Frantoio appears to be the most popular. Our Association has heard of many disappointments in the planting of other varieties. If you are recommended to plant others, we suggest that you ask if you can contact someone with an established grove of that variety, or  treat them as an experimental crop by minimising planting numbers, and assess these in 4-5 years time.              *Young (1-3year old) trees of Barnea are particularly frost prone.

Q. How are olives harvested in Tasmania and what is the cost?      

A. Currently they are picked by hand, with pneumatic, electric, & mechanical hand held rakes, into a catch ground net or dish shaped above ground catching frame. Petrol driven limb shakers are also used. The current rate for pickers is around  $15 per hour. With mature trees yielding 20-25 kg, an experienced picker with a mechanical limb shaker can harvest 100-150kg per hour. Lesser fruit yielding trees are considerably more expensive to harvest. Rakes are slightly less efficient, however if you are harvesting partially ripened fruit, the shaker efficiency is reduced due to increased fruit detachment resistance. Our Association is unaware of any overhead, large combing, or trunk shaker harvesting machines operating in the state.

Q. How much does it cost to extract the oil from my fruit.                 

A. Currently the owners of the larger machines in the state are charging around $400-$450 per ton. Some have a minimum run size. It is recommended that you contact your processor prior to harvesting to ascertain booking time and charges.

Q. What sort of return can I expect from oil sales.  

A. Up to 2005, a few growers with niche market outlets were getting $30-50 per litre. Others achieved around $20 per litre. Tasmania is only just  establishing itself as a producer of premium olive oil. Until this is fully established, we recommend that you base your costing calculations on the world parity price, which is around $4 to $5 per litre.

Send mail to bhinson@tasmanian-olives.com with questions or comments about this web site.
Last modified: May 07, 2008