from the June 1997 Australian Olive Grower)
Mayo is the Vice President of California's Orchard Machinery
Corporation (OMC) and was the International Guest at one of
the 1997 Australian Olive Seminars. OMC supplies advanced technology
mechanical harvesting equipment into just about every country
where fruit, nut and other industries are mechanised. The
following speech is a summary of Don's address at Olives
Australia on March 2nd, 1997.
note that with regular developments being made in mechanical
harvesting a number of the comments made in this speech have been
questioned. Mechanical harvesting techniques and equipment are
developing rapidly and what is "best practice"
today may not be so in ten years time. Please also remember that
Don is a salesman for his machines!
great to be back in Australia. I've been coming here for many
years and I love every visit. Thank you to the Archer family
for inviting me to speak here today.
know you've got lots of questions on mechanical harvesting so
let's get straight into it.
Machinery Corporation has been working with olives for many years.
I remember going to Argentina in the 1970's to work on the early
stages of mechanical harvesting their olives. We have our
shakers working right across the world from Hawaii to Israel
and Argentina to Australia. The majority of our shakers
in Australia are in the Murray Riverlands and at Moree on the
California we have close on 30,000 acres of olive orchards.
As many of you know, California now produces about 11% of
the world's table olives. This was not always the case.
In the early days we planted many orchards for olive oil
but of course we found, as did Australia about 30 years back,
that the low production costs which were then in the Mediterranean
meant that they could land oil in our shops cheaper than we could
produce it. Because of this, many orchards were changed over to
olive oil industry in California is very small and is mainly based
on the cull fruit from the table growers.
SHAPE - The main areas with established olive orchards are
the USA, the Mediterranean and Argentina. However, their
biggest problem for mechanical harvesting is the structure
of their trees. In Australia you have an excellent opportunity
to do things right in the first place. You can choose your varieties,
tree spacings, pruning methods etc etc etc yourselves. You are
inheriting nothing from generations before and this is very much
to your advantage.
majority of trees in the established countries are multi-trunked,
having three or four trunks per tree which makes tree shaking
almost impossible ... and because of the shape and size
of the limbs and the terrain of the orchards, limb shaking is
also out of the question on most of the trees.
just like to make a comment here that I'll expand on later and
that is, don't screw up on your tree spacing. I've seen
major catastrophes in countries such as Argentina where
Mediterranean 'experts' have advised them to plant on spacings
of 6m x 3m, 5m x 5m and even 4m x 2.5m! Never plant any closer
than the 8m x 5m as you've heard recommended here today. We'll
get back to this.
take a look at tree shape and pruning for mechanical harvesting.
This is another area where there seems to be much confusion.
The first important point is to have a single, clear, straight
trunk of 1.0 to 1.5 metres from the ground. This allows
enough room for the harvester to safely and efficiently grip the
tree. It also allows room to spread the catching apron around
structure of your tree above this straight trunk should be some
form of a vase. From my experience I recommend three
main branches. This helps with the carrying of vibrations
at harvest time and also allows for simple limb shaking many years
down the track when the trunk is too large to shake. It is
best to keep an upright "V" in your vase rather
than a flat "V" because again vibrations transfer more
easily in an upwards direction. I'm no expert on the horticultural
side of the pruning but with olives, this vase shape also
helps to let sunlight and air into the tree efficiently.
know that some growers are looking at the possibility of pruning
in a monoconical system where the tree is simply a Christmas
tree shape. The main reason for this, as I understand it, is to
make vibration travel even more efficient during harvesting.
I know many people don't agree with me on this, but I speak
purely from a mechanical harvesting background in hundreds of
orchards around the world, and monoconical is not the best
way to prune your olive.
are two reasons for this. Firstly, in the harvesting business
we have a term called "end tree damage".
This refers to what percentage of the fruit is damaged during
the harvesting stage. The majority of this damage comes
from two sources, fruit to branch bruising as it falls from the
tree and then impact bruising as it hits the ground or catching
frame. Due to the careful design of mechanical harvesters, the
dislodged fruit falls almost directly downwards. As such, in a
monoconical shaped tree, the fruit 'ping pongs' from branch to
branch as it falls down through the tree. In a vase shaped tree,
the fruit falls almost directly from the tree to the umbrella
with very little branch collision. As such, tree shape is the
key to minimising fruit damage.
designs and materials used in our catching frames have reduced
fruit damage to an absolute minimum when it lands on the
second reason for my experience being against monoconical pruning
and upright tree growth comes from work that we do with
mechanical harvesting of pine cones in the USA. When we apply
powerful vibrations to the base of a pine tree we find that
although the cones can be removed very efficiently, the
vibrations travel very quickly up the tree and actually condense
(increase in magnitude) as they focus towards the top of the tree.
As these vibrations condense, the water in the cambium
layer of the tree heats up and damages the trunk. In fact,
we've blown the tops clean off pine trees because of this
condensing effect. Just picture it, the top three feet exploding
with a mass of steam being shot out of the tree top!
pine tree experience may not be as critical in shorter olive trees
but the condensing effect can still heat up the cambium
layer towards the growing tip of your monoconical tree.
what I'm saying is that from a mechanical harvesting perspective,
prune your trees into an upright "V" vase. From my understanding
of your industry, most growers are using this method already.
- A number of people have been asking me about the Fruit
Removal Force for various olive varieties. My experience on
this is limited to the main varieties being mechanically
harvested in California and Argentina but I'll explain a
few points to you anyway.
the early days we harvested Manzanillo's about two months,
60 days prior to when they were ready for green harvesting. Do
you understand that? We were harvesting extremely green
Manzanillo olives which we then processed using the 'black-ripe'
method which you heard about last night. We were getting about
85% of the fruit off the trees. We have now improved our equipment
and changed our harvest time to standard green harvesting
(60 days later) and we now get about 95% success
with the Manzanillo. Naturally, ripe fruit is easier again
5% remaining, or the 15% as it used to be was harvested later
and used for Manzanillo oil.
(Queen of Spain) olives are very easy to harvest with about 95%
coming off when green. Ascolano, a pickling variety we
have in California, bruises very easily. If I never see
another Ascolano olive tree it will be too soon! Mission
is the most difficult to harvest in California and yet we still
remove 95% of the fruit when it is turning from green to black.
I see no problem working with smaller fruit except that the shaking
time will be a few seconds longer to remove the same percentages.
people talk about using abscission sprays which cause the fruit
to loosen on the tree but we have no such sprays registered
in California and so we've simply improved the efficiency
of our machines.
achieve these high percentages because of the specialised design
of our machines. We have what are called Omnidirectional
shakers. That is, our machines have many different vibrating actions
which can be adjusted to suit the type of tree crop being
harvested. With the olives we most commonly use a tiny vibration
which moves the olives slightly in one direction and then quickly
changes direction thus using inertia to break the adhesion point
of the fruit. The next vibration, a fraction of a second
later, moves any fruit remaining 15 degrees to one side
of the first movement and then repeat the same fast change
of direction. This 15 degree change in direction is repeated over
and over for about two to three seconds after which most
of the fruit has been removed.
this same few seconds, the machine changes from high frequency
to low frequency vibrations. This is done because olives at the
top of the tree require high frequencies for removal
and olives on the lower pendulous type branches require
low frequency vibrations for removal. Weeping branches
are no problem with our harvesters because of this advanced design.
might also note that we use mechanical harvesters on olive trees
from when their trunks are about 4" (100mm) thick.
This means that you should be able to harvest from your first
commercial crop in year three or four onwards.
OF HARVEST - We produce two main harvesting machines at OMC.
One is called a Monoboom Shaker. This machine harvests
about one tree per minute but does not catch the fruit.
There are a number of these machines in operation across Australia
especially in certain nut industries where the nut needs to lie
on the ground for four or five days prior to collection.
second machine is the Catchall III. This latest technology
machine does have a catching umbrella for fruit collection and
it can actually harvest at about two trees per minute.
When you compare this to the 30 to 60 minutes per mature tree
for hand harvesting you can begin to see the major benefits.
the past we produced a two machine harvester where one
machine would travel done one row with a shaker head to vibrate
the tree and another machine would travel done the next row with
a catching mat. We stopped producing these machines for
a number of reasons, the most obvious of which are the fact
that two engines, two men and two machines are much more expensive
to run than a single operator unit such as the Monoboom
and the Catchall III. It was also very difficult to find
skilled drivers who could work efficiently together in the
synchronising of the two machine shaking and catching system.
major factor effecting harvest speed is the terrain on
which the machine is operating. Last night you saw the various
methods of caring for the floor of your orchard. My recommendation
is the same and that is that you prepare your land as flat
as possible prior to planting and then use herbicides and slashing
to control weed growth.
harvesters cannot work safely on slopes greater than 25 degrees
and the steeper the slope the slower the harvest rate.
estimating the length of time needed to harvest your trees, reckon
on 10% down time for refuelling and adjustments etc. and
then also take into account the evenness of the terrain
over which the machine will travel. The rougher the ground, the
slower the harvest. Rough ground also takes its toll on
the machinery itself.
- Other than the very obvious savings in labour, and by the way,
with manual hand picking you can spend up to 50% of your gross
income on harvesting ... the next factor of economics to look
at is fruit damage.
hand picking using the 'stripping' method, where a small tool
or hands are slid down the branch removing the olives onto
a mat below, growers expect to have between 1.5% and 2% fruit
damage. With the Catchall III harvester, fruit damage comes
in at around 3%. However, when you consider that mechanical
harvesting of olives costs about US$25 per bin and hand picked
olives cost about US$250 per bin you can see the vast differences
I've already mentioned, Australian olive growers have an excellent
opportunity to do things right from the start. One of these standards
should be in the bin size used across the country. In California,
one of the best things we did was to standardise bins to four
feet square and two feet deep. Get this sort of standardising
through your industry as soon as possible.
California we have about 35 mechanical harvesters in operation
on olive orchards. However, some orchards still need hand picking
because of wrong tree shapes or wrong tree spacings. I can't
emphasise enough the need for you to get your orchard layout right
before you plant your first tree.
SPACING - This is one of the most important factors
in the planning of your orchard. My job takes me fairly
regularly into Adelaide in South Australia and I've just
spent two weeks there again. I am not prepared to mention
names but I'm very concerned at the tree spacings that some people
are promoting in that area. I've seen the same problem in
New Zealand and Argentina. The recommended tree spacings are far
too close for efficient mechanical harvesting and I'm
talking about for any machine. I don't know too much about the
horticultural side of olives but I do know that ...
spacings of less than 8m x 5m are going to cause a lot of
the growers at harvest time.
was actually told about the problem down south by some major almond
growers who we supply machines to. They were very concerned
at some of the information getting around in the olive industry.
You need to understand that ...
planting closer than 8m x 5m is asking for trouble.
anyone is telling you to plant closer then you need to check them
out very thoroughly. They'll often tell you that the harvesting
will be done with the two machine system which we've already discussed
or with some sort of over the row type of straddle harvester.
You can take it from me that the two machine harvesters
are too inefficient and there is know successful over the row
harvester for olives anywhere in the world. Did you hear that?
There is no successful straddle harvester for trees such olives
anywhere in the world. There have been a couple of prototypes
but nothing has been successful yet. To plant an orchard
at a tree spacing designed for harvesting by a machine that does
not exist is ludicrous.
OMC we spent a lot of time and money, and I mean a lot, trying
to design and construct an incredibly advanced harvesting
machine. This machine was self propelled, controlled by
electronic sensors and harvested two rows of trees at
a time! It was by far the most advanced harvesting machine
in the world. But do you know what ... it didn't work. There
are two many variables in tree shapes and heights, pruning methods,
fruit sizes and removal forces for the machine to be viable.
I'm saying is do your homework well and unless you want to hand
pick your fruit,
never plant closer than 5m x 8m.
DAMAGE -Todays OMC harvesters DO NOT DAMAGE TREES.
That's right. We advertise in the USA that our Catchall III and
Monoboom machines will not damage the trees they are harvesting.
Keep in mind that in the USA we are 'sue crazy' which means that
if you even look at me the wrong way I'll sue you! Therefore for
us to advertise this we need to be extremely certain of our facts
... and we are.
University of Michigan study into mechanical harvesting concluded
that "the OMC mechanical harvesting system has the
only non-damaging head available." We fully understand
that damage to a tree's bark is permanent and will reduce the
crop of that tree for years to come.
US Constitution says that "All men are created equal."
And whether you agree with this or not is none of my business,
but let me tell you that all shaker heads are NOT created equal!
The greatest mechanical harvesting advancement in 20 years took
seven years to develop and is now patented standard equipment
on all of our shakers. It is called the "Air Pad System".
old shaking heads and that of many other harvester manufacturers,
consist of rubber pads which grip the trees with various
efficiencies. The harder the rubber, the less it moulds to the
trunk and therefore the greater the pressure being applied at
the contact points. When you switch on the vibrations, damage
can often occur on or below the bark's surface. It's worth noting
that tree shaking should not be done within a few days after
watering. Immediately after watering, the bark is not as strongly
attached to the tree as when the tree is slightly drier
and the bark is more constricted on the trunk.
the Air Pad System, two deflated 'footballs' are placed on the
sides of the trunk. When they are completely in position, compressed
air is released into them causing them to inflate and thereby
gently but firmly grip the tree. These pads surround almost the
entire trunk rather than simply holding it on either side.
of the heat which is generated during the vibrating process, air
is passed through each 'football' at 30psi and released
through a valve on the end. This passing air absorbs the heat
and releases it through the valve, thereby keeping the tree/football
union as cool as possible.
are many other features which place our machines at the leading
edge of mechanicalharvesting but you can see them on the
brochures or videos which I'm leaving with Olives Australia.
- At present the Monoboom Shaker is selling for US$70,000 to
US$90,000 plus about US$4,000 to US$6,000 freight and insurance
to Australia. The Catchall III is selling for US$140,000 plus
about US$10,000 for freight and insurance to Australia.
The majority of OMC harvesters in Australia at present are the
Monoboom Shakers, however, there is a Catchall III working with
cherries in Victoria.
OMC machines in Australia are currently working with stone fruits,
macadamias, walnuts and pecans.
most cases, I expect that the harvesters will be purchased by
investors wanting to run acontract harvesting company, large orchard
owners, and associations and co-operatives buying machinery for
you again for your invitation to speak today. I wish you all the
best as you design, plant and tend your orchards in the
most modern and economical manner. I look forward to spending
more time with the Australian Olive Industry in the future."