About Olive Trees

About Olives ...

Please read these pages thoroughly as they will  answer many of your questions on this exciting industry.

"Australian olive growers are involved in one of the
nation's fastest growing horticultural industries."
(Peter Fuller, The Australian Farm Journal)

Health Recent studies show that olives and olive oil help to lower levels of bad cholesterol and reduce the risk  of heart attacks and certain cancers. The Mediterranean diet which includes plenty of olives and olive oil has long been known as one of the healthiest.

Residents of Crete in the Mediterranean have the highest consumption of olive oil per person in the world and they also have the lowest  rate of death from heart related diseases in the world. It is no secret that the  olive, which has been providing food and medicine to humans for millenniums, is  one of the most versatile and life giving trees on earth.

Olive oil is rich in mono-unsaturated fats and contains no cholesterol. Many nutritionists and medical groups including the National Heart  Foundation are now recommending olive oil as the healthy substitute for other fats in the diet. Olive oil is the only oil which is actually a fruit juice ...  in its purest form, the oil is simply 'squeezed' from the fruit, filtered and  bottled ... with no contamination by any chemical processes.

Olive Oil ... is actually a fruit juice!

These scientifically proven health facts are a major reason for  the ever increasing demand for olive products around the world.

"The modern American, with all his patent  contrivances...will never know...a full tide of health until he returns to the  proper admixture of olive oil in his diet. Until he again recognizes the value  and use of olive oil, he will continue to drag his consumptive-thinned,  liver-shrivelled, mummified-skinned, and constipated and pessimistic anatomy about...in a vain search for lost health."Dr P.E. Remondino, Olive Grower's Convention, California 1891.

A Royal History The first record of commercial olive cultivation dates back over 5,000 years to the region of Syria.  In the five millenniums from that day, archaeologists have been able to track the spread of the noble olive across the entire Mediterranean basin and  beyond.

With a possible lifespan of up to 2,000 years, individual olive  trees have seen not only generations, but entire kingdoms, come and go on the earth's surface.

From Solomon's temple to modern day Tuscany, the olive has had a distinguished career enriching the human race. Countless people have used the olive for an income, food, medicine, heat, light and shade.

From its somewhat mysterious birth on the shores of the  Mediterranean, the olive tree and its fruit have grown into a modern industry  worth an estimated $20 Billion a year.

Imports The health benefits of  olive oil are being learned around the world. In 1991 Australia imported $38 million worth of olive products. By 1996, just five years later, imports had risen to $115 million and they are still rising. (Australian Bureau of Statistics). In fact, over the past decade, Australian olive product imports have increased by more than 300 per cent (Reichelt  & Burr, 1997). Olive oil now commands up to 50 per cent of the edible oil shelf space in some of our leading supermarkets ... but with our own Australian  olive products always sold out well before the next year's harvest, we have to  import around 95% of the olive  products we consume.

Australians consume more olive oil per person than any other country outside of the Mediterranean!

Australian growers have the opportunity of lifting our economy by producing the majority of these olives on Australian soil. Also, rising  labour costs and subsidy changes in the Mediterranean countries are forcing them to increase the export price of their olive products. This gives Australian  growers an increasingly competitive edge over import prices.

Exports Australian growers are  encouraged to reduce the ever increasing imports by producing olives in  Australia, for Australians. However, a number of Australia's larger growers are  planting solely for export purposes. They will send all of their produce into the rapidly expanding Asian and American markets. Asia is beginning to demand a  more varied Western diet and along with this comes the desire for items such as  pizza's topped with sliced or whole olives, olives in salads, and the use of quality olive oils for salads and cooking. With around two billion people, the  possibilities are almost endless.

Japan's imports of olive oil almost doubled from 1995 to 1996  when they reached 16,637 metric tons. (Nikkei Kezai Newspaper 20/11/97) And in  the 1997/98 year they imported a staggering 34,228 tonnes! (International Olive Oil Council) The USA is importing 100 times the olive oil they produce and the best marketed Californian oils are selling at unrealistic retail prices of up to US$100 per litre. (San Francisco Chronicle) Taiwan, Malaysia, Singapore and many northern European countries are also rapidly increasing their demand for high  quality olive products.

Marketing Olive Crops As with any business, there is a need to have a market for your product. It is true that the  market for olive products has been around for 5,000 years and is currently a multi-billion dollar industry, but there is still a need for every Australian  grower to find a buyer for their fruit or products. There are three main options for the selling of olive crops in Australia.

In the past, Australian growers have needed to focus on the  sale of fresh olives to produce markets or on-site processing in which case they then needed to market the oils and table olives they produced.

Produce markets are still buying olives and the on-site  processing option is still viable for people with the necessary processing and  marketing skills. However, the construction of small and large scale olive  processing factories across many regions of Australia has opened new doors to olive growers.

Processors in most states are now offering contracts to olive  growers for their fruit at set prices and qualities. A number of processors are  also offering contracts on quality fruit from growers prior to the grove being planted.

Tree Appearance The olive is a  handsome tree with silvery grey-green foliage. Olive trees were selected at the Sydney Opera House as the sole tree planted on the Harbour side in 1973. Now, over twenty years later, these trees in large planter tubs, are still growing  and fruiting. The architects chose olives because of their beauty, lack of untidy bark and leaf shedding, ability to withstand the battering of storms,  salt water, heat and cold, and their evergreen nature.

Non-Fruiting Olives Many ornamental olives grow in suburban backyards across Australia. Over the years, many people have mistakenly bought these olive trees from nurseries, not realising that they  are only for ornamental purposes. The leaf is a darker green colour than the commercial varieties and does not have the same silvery grey-green appearance. As the trees grow to  maturity they produce a tiny pea-sized fruit which has no value. The tree's owners then assume that olives do not do well in their area. The problem is  simply that they have the wrong tree. With commercial olive trees, lack of water  and nutrients and other general care problems can also result in very little fruit.

Varieties of true commercial olives crop well from the cool  winter areas of Queensland through New South Wales, Victoria and Tasmania in the  south, and across to South Australia and Western Australia.

Drought Hardiness Down through  thousands of years, the olive tree has proved to be very drought hardy. When  many other trees have died, the olive tree has always been amongst the few  survivors. Unlike many other fruit orchards, an olive grove can be neglected for  a number of years and then simply be rejuvenated to bring it back into  production.

Lifespan With minimal care olive trees will live and produce fruit for well over a thousand years. This has been demonstrated in the Middle East and places like the Garden of Gethsemane in  Jerusalem. There are no age limits to the commercial viability of an olive grove  on average fertility soils, provided that the tree receives suitable annual  pruning, water and fertiliser. A suitably cared for orchard planted on the  common 5m x 8m spacing can be commercially viable for well over 100 years.

As a Gift The  olive tree is a symbol of joy, peace and happiness and as such makes an excellent gift. Because of its general hardiness, people who don't have 'green thumbs' will find them fairly easy to care for. With normal care, the olive tree will generally outlive any human and give useful food for many  centuries.

Windbreaks Olives are regularly  grown on properties throughout the world as a handsome windbreak and avenue  tree. Windbreak spacing around properties can be as close as three metres (10  feet), but don't expect heavy crops per tree at this closer spacing.

Real Estate Value Olive groves, avenues and boundary plantings increase the value of any property. The olive is  a hardy tree, handsome in appearance and valuable for fruit.

Soil Types Olive trees will  tolerate a large range of soil conditions, preferring a neutral to alkaline soil  type. If your soils are acidic, they may be easily changed to an optimal pH of 7.0-8.0 by simple methods such as the addition of agricultural lime. Check with your local fertilizer company or lime supplier if you need your lime quantities worked out. Our OLIFAX 15 sheet will  give basic information about the use of lime in your olive grove's soil. Olives will often grow in hilly, rocky areas that are not suitable for other crops.  However, they do not like very heavy soils that hold excessive water after wet periods.

It is important to understand your soil type, structure and pH prior to planting. After the trees are in the ground, there is very little you  can do to alter drainage and other essential factors. You can buy a very easy-to-use pH Test  Kit from Olive Agencies to do your basic tests.

Climate Olive trees like cool/cold  winters and hot summers. Even though olives are evergreen trees, they still need a cool winter so they can rest to prepare for their main shooting, flowering and  fruiting in the spring. For most varieties some winter frost is preferred.

Throughout the world olives are grown in climates which range  from the cold of Tuscany (Italy) where minus 20 degrees Celsius is not unheard  of, through to warmer areas such as Seville (Spain) where some regions don't even reach 0 degrees Celsius during winter. Summer temperatures are important for the growth of fruit-bearing foliage. Most olive growing regions of the world  have average maximum daily temperatures, in the hottest month of summer,  somewhere above 30 degrees Celsius. Afternoon temperatures as high as 45 degrees Celsius have very little effect on mature olives as they have an inbuilt mechanism which temporarily shuts down their system until the cooler part of the day arrives. However, apart from the cool winter and warm summer requirements,  the moisture levels of the tree must also be adequate. (See the enclosed copy of OLIFAX - 1 and the World Olive Climates article for more climate details.)

Frost Many mature olive trees will survive and crop well even in the very cold areas of Australia. Some varieties will also fruit well in 'no frost' areas as long as  the winters are cool enough. Short cold snaps of down to minus 10 degrees Celsius are often not overly detrimental to mature olive trees with sufficient  moisture in the soil to avoid stress. Some varieties have been seen to survive  minus 15 degrees Celsius as long as they are in good health. Most olive trees will be killed to the ground in an extreme freeze of minus 20 degrees Celsius  such as can occur in the coldest olive growing regions of the world. However,  such severe temperatures are quite rare in Australia.

An important aspect to be considered is the effect of cold snaps on young trees. It is not advisable to plant young olive trees during  winter if your temperatures fall below minus 5 degrees Celsius. Very young trees  can often handle temperatures down to minus 5 degrees Celsius (as they sometimes do during their growth at Olives Australia), but they must be kept in good health and have sufficient moisture. Keep a good eye on the health and moisture  levels of your trees during winter to ensure that no damage occurs.


"Once again we thank you for your honesty and help in  the growing of
another lot of trees that will tolerate the low  temperatures."
O.W. & S.W. Sandy Flat (NSW)

 Warm Winter Research Grove AWarm Winter Research Grove has been set up to assess over 70 varieties. The trial site has an average daily temperature of 13-14 degrees  Celsius in July which is considered 'marginal' (too warm) for traditional olive production. The results of the trial will not only identify olive varieties  suited to warmer winter climates of the world but will also assess numerous  grove management practices for the benefit of the entire Australian industry. 

Tree Spacing

Traditional (non-irrigated) 10 x  10m = 100 trees/ha

Medium Intensive 8m x 5m = 250 trees/ha

Medium Intensive 8m x 4m = 312 trees/ha

Intensive 7m x 4m = 357 trees/ha

Intensive 6m x 4m = 416 trees/ha

Intensive 6m x 3m = 555 trees/ha

Super Intensive 3m x 1.35m = 2,470  trees/ha

The vast majority of new Australian groves are being spaced at 8m x 5m (250 trees/ha). Some growers are selecting more intense spacings. The main factor affecting the spacing decision is the type of harvesting machinery to be used on the grove. Harvesters are manufactured for all densities but their  availability to your grove's location must be considered.

In the majority of groves, the best yield per hectare over a thirty year period comes from trees planted 5 metres apart in hedges, with a space of 8 metres between the hedge rows. This spacing is 250 trees per hectare (104 trees/acre). Earlier returns and increased returns per hectare in the early cropping years can be gained on more intensive groves. However, the long term effects of close spacings on pruning, harvesting and pest management must also be considered.

There is ongoing research in every olive growing country to  ascertain the best tree spacing for mechanically harvested olive groves. While there has been a tendency towards closer spacings in the last decade, harvesting economics on densities closer than 400 trees per hectare are still being  assessed.

With densities greater than 200 trees/ha (hedge planting), it  is important to run the hedge rows approximately north/south so that the sun  penetrates the foliage of all trees in the hedge most effectively. The basic rule for olives is - "more light penetration equals more fruit per branch".

When to Plant It is widely accepted that olive trees can be planted in irrigated olive groves year round if the winter temperatures do not fall below minus 5 degrees Celsius. Traditional  plantings in Mediterranean countries are done in the autumn leading up to the winter rains. However, access to irrigation water reduces the need for such seasonal planting. A properly irrigated grove will withstand much greater extremes in temperatures than a traditionally planted dryland grove.

Olive trees going into groves which regularly go below minus 5 degrees Celsius or are not irrigated correctly will need to be  planted outside of the winter period.

Planting an Olive Tree

Just like any tree, there's more than one way to plant an olive. Over our past 25 years of planting, growing and researching olive trees  we have observed and tested many such planting methods. With these trials and research in mind we have concluded that there is an optimum way to plant olive trees for maximum results.

Over the years, our customers have tried many methods with varying degrees of success. However, one thing that has been clearly displayed is that trees planted in suitable climates, according to the steps below, can  grow approximately one metre per year in both height and breadth, in their early  years. This is faster than any other natural methods we have seen.

So here they are - the steps for planting a healthy, fast  growing olive grove. If you follow these steps we believe that the long term  results will please you.

1. Manure Manure should be added to the soil prior to planting. Manure adds micro nutrients and miro-organisms to  the soil that will greatly benefit the health and growth of your trees. Most  manures are suitable as long as they are not too fresh.

For large groves, a fertiliser spreader will efficiently add the manure to the soil surface. Your manure supplier or fertiliser company  should be able to organise a tractor-pulled spreader for you.

Apply the manure at the rate of one cubic metre to every twelve  trees. Spread a strip of manure along the tree line about 3 or 4 metres wide.  (NB. On the 8m x 5m spacing, one cubic metre of manure will be applied over a  distance covering 12 trees (60 metres) and 3 to 4 metres wide.)

For smaller groves, the rate is approximately one builder's  wheelbarrow fully spread over 3m x 3m at each tree site. Approximately 12 full  wheelbarrows make up one cubic metre.

2. Blue-metal (basalt rock) crusher dust should also be spread along the row in the same way that the manure was  applied. This product is very high in minerals and is the main ingredient in rock dust fertilisers. There minerals are not easily water soluble and therefore will not be wastefully leached out of the soil. The nutrients are available to the tree roots as required.

Once again a rate of one cubic metre for every 12 trees (60  metres) is excellent. In size, the product should be fine dust through to small particles no larger than 4mm. Blue metal crusher dust is very heavy and one cubic metre weighs around 1.5 tonnes.

Again, for smaller groves, the rate is approximately one builder's wheelbarrow fully spread over 3m x 3m at each tree site. If it is  extremely finely screened (less than 1mm particles) then as little as one half  barrow full per tree site may be enough. OLIFAX 10 is  available if you require more information on blue-metal basalt crusher  dust.

3. Lime If your soil requires the addition of lime to bring it's pH level to 7.0-8.0 (neutral to alkaline), then  add the required amount to the manure and crusher dust above. Contact your local  Department of Agriculture or fertilizer company if you need pH testing done and lime quantities worked out. Many growers use a spreading contractor to apply the  lime along the total row rather than just at each individual tree site. Your own  inexpensive pH test kit will be handy for spot checks throughout the grove. More details on the use of lime for olive tree health can be found in OLIFAX 15.

4. Deep Ripping Next, deep rip at least 10 to 12 furrows along the full length of the planting row to a depth of  600mm or more and a width of at least 3 metres. The nutrients will be suitably mixed in as they drop down the ripper grooves. This preparation will give the  roots an excellent start and fast growth will result. Wide shoed rippers pulled by a good sized dozer will do an excellent job. You may wish to finally level the ripped area with offset discs, a rotary hoe, blade or similar.

In poorly internally drained soils, deep ripping both along the  rows and then some cross-ripping will increase subsurface drainage. Please  consider possible erosion when planning the direction and timing of your ripping. Deep ripping during a heavy rain season may result in erosion if grass  cover cannot be quickly re-established.

5. After selecting the tree site, positioning your stake, and wetting the planting site, plant the tree at the same depth or just slightly deeper than it was in the pot. Do not tease the  roots out before planting as this will stress the tree by damaging the young brittle roots.

6. Press soil down lightly around the tree roots to remove any air pockets and make a slight depression to act as a watering basin.

7. Water thoroughly immediately after planting and mulch with coarse straw to conserve water, cool the soil, and reduce weed growth. The best mulches to use are those that contain plenty of nitrogen and other minerals to feed the tree. These include lucerne, soya bean and pea hay. As the mulch decomposes over a period of time, the nutrients are  transferred into the soil by earthworms, rain and micro-organisms. If using mulch, try to buy spoilt (rain damaged) bales, which are often available for  just one or two dollars each. Loosen up the 'biscuits' before applying.

Hammer milled pine wood waste can also be used but an  occasional nitrogen fertiliser application will be needed to reduce its leaching  effect. Carefully used, well rotted manures can also produce an excellent  mulch.

If you are in an area with long, cool, wet winters then mulch  may hold too much water during this period. Remember to keep your mulch about 100mm (4") away from the trunk to allow the tree to breathe and to avoid contact between the trunk and wet mulch.

8. Continue your irrigation according to the section on "Irrigation" and using general common sense. Be  careful not to waterlog the soil as excess water is the olive's worst enemy.  Further information can be gained by reading OLIFAX 5 on  Irrigation.

NB. All trees are 'container grown' and can be planted in  moderate climates (eg. winters that don't go below minus 5 degrees Celsius) at any time of the year. Very young trees may need some protection from severe  frost and animals. No transplanting shock will occur if the simple instructions above are followed.

Congratulations - Now watch your olives  GROW!

 Staking The staking of young olive trees is very important. Stakes need to be strong enough to support the tree while the anchor roots are developing, and yet flexible enough to allow the tree to move freely in the wind. If the stakes are too rigid then the tree will be  over supported and not sense the need to develop strong roots and a thick trunk.

Our commercial grove sized trees are only lightly staked and will need to be tied to a heavier stake at or soon after planting out. The trained straight trunk will make fruit harvesting easier if a 'tree shaker' is to be used. The final stake should be 1500mm long and 16-20 mm thick. Two types  of stakes - coated steel and bamboo - are available from Olive Agencies.

The steel stakes are coated in a hardened, waterproof and UV stabilised polyethylene and, like bamboo, are smooth, light and flexible.  Because of their durability, they will last many years and can be used a number of times. The stakes are 1500mm long and are approximately $1.40 each plus  GST.

The bamboo stakes have a diameter of about 24-26mm, and are  1500mm long. Please contact Olive Agencies for a current price.

Correct land preparation and the use of under-tree sprinklers  rather than drip irrigation can also help the roots to spread widely and thereby  assist in the overall stability of the tree.

Trellising A small number of grove owners plan to prune their trees in the monoconical style (see OLIFAX 9). If you choose to go in this direction then you must seriously consider the use  of a supportive trellis. Due to the very upright nature of a monoconically  pruned olive tree, support is needed either in the form of a tall solid stake (2.0 - 2.5m tall), or a trellis wire system.

The most common trellis system is a single tight wire at 1.5 to  2.0 metres from the ground. Fibreglass or heavy wire stakes are then placed at each tree site and attached firmly to the trellis wire above. The tree is then tied to the stake as it grows. The trellis wire gives the necessary support  during windy periods.

This system is more expensive than the common bamboo stakes  used on traditionally pruned groves but is necessary for the development of monoconical groves. Trellises are also used in groves with densities greater  than 400-500 trees per hectare as monoconical pruning is considered the only  viable method for such intensities.

Irrigation Olive trees need very little water to survive if serving as an ornamental or landscape tree. However, for a good crop, mature olives generally need at least two waterings to field capacity (full depth of roots - approximately one metre in mature trees), each winter (this will depend on your soil type). If more is available during winter and at other times of the year then this will be most beneficial and will result in increased crops. In fact, it is generally accepted that a drastic reduction  in rainfall and irrigation water will result in a poor crop of only one third to one half of a fully irrigated commercial crop.

It must be remembered however, that the olive's worst enemy is too much water - especially during the winter months when there is less  evaporation taking place. So keep a good eye on the moisture levels in the soil  around your trees. Winter watering keeps the trees healthy for a good spring  flowering and a good fruit set. When the fruit has set, in addition to natural  rainfall, supplementary watering is needed to achieve a good fruit size and high oil yield per hectare.

Water Requirements Many factors can  affect the water requirements of any plant. Soil type is an obvious variable - a tree planted in sand is  obviously going to need more regular waterings than a tree in heavier soil  because of the fast draining nature of sand. Also the grove's local climate - if trees are planted in an area  which receives 300 days of sunshine per year they will need more water than  those planted in a cloudier climate which may only receive 200 sunny days per year. Another factor is annual rainfall - this is the most obvious variable when considering the tree's  supplementary irrigation needs.

When calculating your irrigation requirements you must always  look ahead to what the olive trees will be needing when they are mature rather  than the smaller quantity needed while still small. It is widely accepted that a  mature olive grove will use between 6 and 10 megalitres of water per hectare per  year. This quantity includes usable rainfall. Therefore, if your usable rainfall is 5 megalitres per year, you will need to allow between 1 and 5 megalitres per hectare via irrigation.  Your local irrigation specialist will know the usable rainfall for your region. See OLIFAX - 5 for more irrigation details.

Water Quality Every tree likes good quality water but the olive tree is still one of the few fruit bearing trees  that will survive and still bear quite well with poor quality saline (salty)  water. Saline water that is unfit for human use is generally quite suitable for  olives. Olive trees grow and crop well using water with a conductivity of up to  2,400 micro S/cm (This can be translated to Total Dissolved Ions by multiplying  by 0.64. eg 2,400 mS/cm x 0.64 = 1,536 TDI). If saltier water is used, it should  not be sprayed onto the leaves and the ground will need to be 'flushed' with good rain water from time to time. The higher the conductivity increases above  2,400 micro S/cm, the more the olive crops will begin to decrease in  tonnage.

If poor quality water is used on your grove, consult a soil  nutitionist to maintain the correct nutrient balance.

Weed Control Although controlling weed growth is a simple process, many growers find it to be the most time  consuming part of their young grove's management. To achieve early crops, weeds must not be allowed to grow around or near the tree, especially in the first couple of years. Weeds compete for water and nutrients, and when totally out of control, even light. Competition from weeds will slow down a young tree's growth  and may cause sickness and even death if not addressed.

Keep a 'weed free zone' from the base of the trunk to at least 300mm past where the foliage stops. As the foliage increases in diameter each year, so the diameter of the "weed free zone" will need to increase also. The  majority of the tree's roots are in this area and must not be held back by weed competition. This area can be kept free from weeds with the careful use of herbicides and/or mulches.

There has been no recorded damage to olive trees of any age  from careful use of glyphosate herbicides (eg. Roundup). Recommendations for  herbicide use are available from the suppliers. Grass and weeds outside of the 'weed free zone' should be kept down with regular slashing or mowing. As the trees grow, the root zone becomes more extensive. It is ideal to keep a  continuous weed free strip along the entire tree row. Mulching around the trees  produces beneficial results.

Growers are trialling the various options available for  intercropping olives with grasses, legumes and other crops. At this stage it is believed that the crops/grasses which are used in vineyards are compatible with  olive groves. You will need additional irrigation if you choose to intercrop. Cover crops may be slashed and used for mulch.

Pruning There are many different  ways of pruning an olive tree. Each country and region has differences in their pruning technique and many will protect their traditional or modern method 'to the death!'. Steve Sibbett of the University of California put it well at a  recent Olive Expo when he said, "There are only three things to argue about in  this world, Religion, Politics and Pruning."

There are however, some basic pruning facts to keep in mind. Firstly, olive trees need sufficient light and air through their foliage to bear  commercial crops. Light and air through the canopy also reduces the incidence of  pests and fungal problems. The most common way of ensuring this is by pruning  the tree into a vase shape. The tree is then open in the centre thus allowing light and air penetration.

For general grove hygiene, cut any branches off that hang too  close to the ground and remove any dead branches. Also remove branches that cross over in the middle of the tree.

In mature groves, the main pruning is done after the fruit is  harvested in Autumn. For most mechanical harvesting machines, the trunk needs to be free of branches for a height of around one metre from the ground. See OLIFAX 4A for pruning details for young trees.

Fertilising For average soils, the  initial application of manure, blue-metal crusher dust and lime is adequate to  get the trees off to a good start. From then on, a yearly 25mm (1") mulch of well rotted manure can be added to the surface of the soil. The manure should  extend out at least as far as the leaf line. This manure mulch will conserve  moisture in the soil, reduce weed growth, and add nutrients to the tree roots.

The annual manuring should be done in autumn/winter after the  fruit has been harvested. Water, earthworms and other micro-organisms will  transfer this food down into the soil. As the earthworm population increases,  this will also do an excellent job of aerating the soil.

For logistical reasons, most large scale olive groves simply use urea and other fertilisers and trace elements to supply soil and foliage  nutrients throughout the year. Fertigation, where the fertiliser is added  through the irrigation system, is a common and economical way of supplying  nutrients.

Leaf analysis is used to identify the nutrient status of the tree. Any deficiencies and toxicities can be found this way. See OLIFAX - 6 for more  fertilizing details.

Diseases Olive tree diseases are relatively minimal in Australia. Those which we do have are controlled through either preventative or remedial measures.

The main fungal problem is known as Peacock Spot (Cycloconium oleaginum). This  grows on the leaves, finally causing the leaf to drop from the tree. Severe  cases can defoliate a tree leading to reduced crops and occasionally even loss  of the tree. Simple control measures include the use of copper  fungicides.

A root problem which is usually found in overwatered groves is called Verticillium Wilt (Verticillium dahliae). Research is still being done into the exact cause of this problem. It is not commonly seen in the Australian Olive Industry.  Olives can also be affected by Phytophthora and again, this is generally  encouraged by excessive soil moisture and a lack of oxygen around the  roots.

Insect Pests These are currently fairly much restricted to the brown olive scale and olive lace bug. Insect pests will be minimal if the trees are kept in good health. At any rate, the need to spray for insects is minimal. Check with a local agricultural chemical supplier  to see which chemicals are registered in your state.

Assessment of some olive fruit found with 'maggots' in them is still occurring. Although the Olive Fly (Dacus  oleae) has not been identified in Australia, the study  of any maggots in fruit will give an accurate understanding of the fly problems  on olives in Australia.

For further details on any pests and diseases outlined here  please ask for the appropriate OLIFAX sheets.

Birds Birds do not generally favour the fruit because of its extreme bitterness before processing. However, some  Australian growers have reported a small amount of damage to ripe fruit (black) by starlings. In certain areas growers have cockatoos or parrots 'pruning' the tops of their trees. In large trees this is not a problem but young groves in  such areas may need some form of protection in the early years.

Animals During times of drought when food is scarce, very young trees may need to be protected from wallabies and kangaroos. If necessary they will nibble off the leaves for food. Hares and  rabbits can also chew the bark and they will occasionally vandalise the trees by  nipping through very young stems. Keep sheep and other stock away from olives as they chew the foliage and bark when their normal diet of grasses runs  out.

Protection from animals can be done with tree guards (small  animals), or by a netting fence around the total grove. Olive Agencies has flute board tree guards and heavy protection netting for individual tree  protection.

Production Trees that have been planted and cared for correctly, begin to produce olives about three years after  planting and the first commercial crop arrives in year four. From Australian trials carried out on 14 varieties by the Department of Agriculture in Mildura, five year old trees produced an average of 27kgs of fresh fruit. Ten  year old trees produced an average of 77kgs per tree. Fourteen year old trees produced an average of 128kgs per tree.

These yield statistics came from fully irrigated trees. In low rainfall areas where extra irrigation water is not available, the yields will be considerably less than the above figures. Good irrigation and tree maintenance practices or lack thereof, will either increase or decrease the annual yield.

Further information on the production of specific varieties can  be gained from the "Varieties" section and the technical staff at Australis Plants.

Harvesting Fruit is harvested green  (unripe), turning colour (half ripe), or black (ripe) between February and June  each year (This will vary according to the latitude and climate of the grove).  The fruit is then processed by yourself or sent to an oil processor, fresh fruit  market or pickling factory. The fruit can be hand picked or raked out of the trees by using a garden type rake with fairly close prongs. Olive Agencies can supply a range of harvesting tools from simple hand rakes through to pneumatic  harvesting tools and beyond. A ground sheet of nylon mesh, plastic or cloth can be used to collect the fruit.

Mechanical harvesting of fruit is currently done by a range of  'tree shakers' which can be fitted with catching systems to collect the falling fruit. Mechanical harvesting methods are used with varying degrees of efficiency  depending on the machine design and the grove suitability. Firms offering contract mechanical harvesting are becoming available in Australia.

Pickling Instructions For wholesale and retail nurseries, simple instructions for non-chemical home pickling are attached to the trees as they leave our nursery. They are enclosed in a clear, waterproof packet and will assist you in your nursery sales. Would you like to read an article which outlines a number of Pickling Methods?

Oil Extraction Olive oil is  extracted from healthy fruit between March and June. There are two main types of  machinery used for the extraction. The traditional press is a series of mats on which layers of crushed olives are placed in a paste form. These mats are then squeezed very tightly together and the oil and water are squeezed out of the paste. The water is then separated from the oil before the oil is ready to use.  The mats are then manually cleaned and reused. Intensity of labour and hygiene  difficulties have always been encountered with the old traditional mat  system.

The most modern factories use the hygienic continuous flow oil extraction machines. These machines allow for a single person to add the olives at one end where they are then washed and crushed into a paste. The paste is then mixed to start the separation of the oil. It then goes through a centrifuge which separates the oil and water from the paste, and finally into a separator  which divides the oil from the water. The oil then comes from the machine with  very little intervention by people involved. There are a number of types of continuous flow machines which vary in the processes outlined above. This continuous flow method greatly reduces labour costs and increases production output and hygiene.

There are continuous flow olive oil factories or traditional presses in all olive growing states of Australia. As crops increase, new  factories are being opened to cope with the demand.

The book, "An Introduction to Olive Oil Processing - From  Picking to Pouring" is available from Olive Agencies and is a valuable  resource for olive growers and oil producers alike.

Olive Products Olives can be marketed in a wide selection of products and packagings, and include the  following:

Green or black plain, herbed, stuffed, or sliced pickled olives, in bottles, cans or vacuum packaging. These olives can be processed using many different recipes, each with their own unique flavours. One Australian company even produced chocolate coated olives!

Olive oils are processed and sold in many different grades. Oil  is marketed in bottles, pressure packs or cans. Herbs or even olive twigs with  leaves can be added to the bottles for that 'something different' gift. Olive  oil is also used in margarines and other mainstream foodstuffs.

Olive oil soaps are produced as blocks or in liquid soap and powder form. Soaps and oils can also have different scents added to them to  appeal to all 'tastes'. The Japanese are using olive oil in a wide range of cosmetics, shampoos, conditioners and health products.

Green and black olive paste can be marketed for use as a spread  on bread or for adding to salad dressings. Olive dips are produced for use with  biscuits or other snack foods. Many souvenirs in olive growing countries are made from olive seeds and olive wood. Olive groves are also developed as tourist  attractions, complete with retail stores, cafes, chapels and processing facilities.

Olive Leaf Extract is proven to be anti-bacterial, anti-viral and anti-fungal.

Olive by-products such as waste cake and olive seeds are being used to produce everything from electricity to fertilisers, stock feeds,  activated carbon, bricks and even plastics.

Due to continually rising demand, it appears that the number of  commodities and methods for the marketing of olive products is limited only by human imagination.

In-depth articles on the logistics of marketing Australian olive products can be found in the Australian Olive Grower Magazine.

Financial Returns Olive Agencies have a Financial Assumption Guide for olive groves of various sizes and uses.... write to us and ask for them to be emailed to you. 

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