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1.Tips On Choosing Fruit Trees

There are hundreds of different fruits to choose from, and we offer most of our trees on a choice of

rootstocks. Given all of this variety, how do you choose? Some people prefer to just jump right in

and choose what strikes their fancy, and for folks with some gardening experience this works justfine. Others prefer a more methodical approach. Start by doing your research locally – have a look

around and see what‘s already growing in your area. Talk to your neighbors & county agricultural

extension to find out what does well in your area. Pay attention to your site, the patterns of sun, wind

& frosts. Look for the microclimates, cold spots, hot spots and sheltered areas.

Find out what condition has the most limiting effect on fruit growing in your area, and keep this in

mind when choosing. In northern regions it may be extreme winter cold, while some southern areas do

not get enough chill for certain fruits such as cherries & filberts. In some areas Spring frosts may

damage blossoms and reduce fruit set certain years. Once you‘ve determined your limiting factor(s)

you can make choices accordingly. Choose hardy varieties for extreme cold, low chill varieties for

southern climates, disease resistant varieties for cool, damp climates etc. Make the most of your site

and climate. Extended rain & fog in coastal areas contribute to disease problems in tree fruit, but is

ideal for berries. Choose plums and early to mid-season disease resistant apples for coastal areas,

avoid the late season fruit that may not get enough time to ripen.

Here's what you need to consider when buying fruit trees:

Rootstock Selection Determines Tree Size and Spacing

Climate Zones

Pollination

Chilling Requirements

How Many Trees Should I Plant?

Ripening Times

Rootstock Selection Determines Tree Size and Spacing

The rootstock is the lower portion of the tree that you don‘t see. Rootstock selection and pruning

determine the size of a tree. If you have limited space, choose a dwarf or semi-dwarf rootstock and

keep it well pruned. If you want a tree to hang a hammock on, or to use as windbreak or shade, go for

a semi-standard or standard.

Climate Zones



There are two aspects to consider for climate – what is the general climate of your area, and what are

the specific characteristics of your piece of property. Climate zones describe the macroclimate or

general characteristics of your area. By learning your climate zone you can gain a lot of useful

information such as average minimum temperature, weather patterns and number of growing days.

The specific characteristics of your property are your microclimates , which you can familiarize

yourself with through observation. Microclimates are determined by soil, slope, aspect, wind andwater. If you have a small backyard plot you may not have many microclimates, but if you have a

parcel with some slope and differing vegetation you‘re likely to have several. Once you identify your

microclimates you can use them to your advantage when planting fruit trees

Macroclimate

Wherever possible, we classify varieties using two climate zone systems – the USDA climate zones &

the Sunset Gardening climate zones. Most gardeners are familiar with the USDA zones, they account

only for the minimum average annual temperature so they are used to rate a plant‘s cold -hardiness.However, there is more to growing conditions than minimum annual temperatures. Sunset Gardening

has developed a different system of climate zones that is far more informative, taking into account

factors such as frost-free days, humidity, prevailing winds, effects of ocean, elevation & regional

weather patterns. Until relatively recently Sunset zones were available only for the western US. Now

the entire country has been classified using this system, and we highly recommend utilizing it.

Don‘t be afraid to exper iment – Keep in mind that a climate zone is the map, and your site the actual

territory. Most written advice (this catalogue included) will be conservative by necessity. Climate

zones do not account for your slope, aspect & local weather, warm spots and frost pockets. These all

add up to your local microclimate, which may vary from what a climate zone tells you. Use the

climate zone as a guideline, not an absolute. Use the information in this catalogue to make educated

choices and avoid varieties that are obviously not suited to your climate. Don‘t be afraid to

experiment and try something new. Ultimately the only way to know how a fruit will produce on a

specific site is to plant it there.

Microclimates - Making the Most of Your Location

Microclimates are small pockets of climate variations that differ from the surrounding climate. By

identifying and using microclimates you can grow fruit not normally recommended for your climate

zone. Pay attention to the way the sun travels across your property throughout the season. Look for

cold spots and hot spots. A maximum-minimum thermometer placed at different locations will tell

you a lot about your microclimates. Here are a few other things to look for.

Slope – Bear in mind that cold air moves like water, so in spring and fall a valley floor will usually be

significantly colder than a slope. In fact, some slopes are called banana belts, because they remainfrost-free much longer than valley floors, which may be subjected to hard frosts. If you are in a warm



climate and are concerned about not having enough chill, plant in low spots when possible. If you are

in a cold climate and are concerned about frost damage, make the best use of slopes when available.

Aspect - A south-facing slope is, of course, much warmer than a north-facing slope. Western slopes

receive the hotter, more intense afternoon sunshine, while eastern slopes receive the less intense

morning sun. A south facing wall is a good place to plant a tree that needs extra heat in order to ripen.

If the wall has an overhang, it will also provide some frost protection.

Thermal mass – Water and stone will absorb heat during the day and re-radiate it at night. A stone or

brick wall can be an ideal place for ripening a late fruit crop. Translucent jugs of water placed in a

greenhouse or around fruit trees will re-radiate heat at night. A small pond will serve as a heat sink in

the summer and fall, and a cold sink in spring and winter. Watering before an anticipated frost will

increase re-radiated heat – the wet soil will absorb more heat than dry soil during the day, and releasemore at night.

Wind – Strong wind can desiccate plants, damage fruit and decrease air temperatures. Wind

protection can be especially important in coastal or desert regions. The best windbreak is one that

slows wind down rather than stopping it. Hedges, vines, lattice fences and screens allow some wind to

pass through without creating turbulence.

Pollination

Most fruit trees require pollination to produce fruit. Some trees are capable of pollinating themselves

(self-fertile), others require pollen from another tree (self-sterile). As a rule of thumb, pollenizers

should be no more than 50 feet apart from one another.

How Many Trees Should I Plant?

The number of trees you plant will depend, of course, on how much fruit your family consumes. The

―At a Glance‖ tables in the catalogue and on the website tell you how much fruit you can expect to

harvest from each variety on different rootstocks. Don‘t be intimidated by the quantities. You can

spread your harvest throughout the season so that your fruit does not ripen all at once. Some of the

fruit will be culls and a lot of weight is lost when processing fruits. If you intend to preserve your

fruit by juicing, canning or drying then you will want to plan accordingly

Ripening Times – Spread Your Harvest Through the Year

By choosing varieties that ripen over a long period of time you can enjoy fresh fruit for most of the

year, especially here in the west. Some varieties are good keepers and will provide you with fresh

fruit well into the winter. And don‘t forget canning, drying and freezing. Most of the varieties in this

catalogue are presented in order of ripening, from early to late.

http://www.sandybarnursery.com/choosing-fruit-trees.htm






2. Caring For Bare Root Fruit Trees

CARE BEFORE PLANTING SITE SELECTION DIGGING THE HOLE

PRUNING & PLANTING CARE OF YOUNG TREES

CARE BEFORE PLANTING

Realize that all bareroot stock, though dormant, is also in a state of shock. They have been dug up

from the field with an inevitable loss of roots, and need special care even before planting. The most

important thing to remember is KEEP THE ROOTS MOIST. Even for brief periods, i.e. while

transporting them to the planting site. If you have not pre dug the holes for your trees and must keep

them for more than a few days, they should be HEELED IN (buried in a moist medium), in a shady

spot and watered thoroughly. Keep the roots packed in sand, peat moss, potting mix or aged sawdust

(avoid fresh sawdust or wood shavings as they may contain compounds that inhibit root formation).

Trees can be kept like this for several weeks if necessary, but should always be permanently planted

before showing any signs of bud swell or growth. Protect trees from freezing before planting. Prior to

planting, SOAK TREES IN WATER FOR 12 TO 24 HOURS. This will afford them a good long

drink to compensate for any moisture loss in storage and shipping.

SITE SELECTION

Each plant has specific needs such as drainage, soil type, soil fertility, exposure and moisture.

Generally, a moderately fertile and well drained site is best. Do some research to find out the

requirements of your plants (see references below). When choosing a site, pay attention to

microclimates. Cold air, which may cause damaging spring frosts, drains away from slopes and ridges,

making them good sites for planting. Planting near a south facing wall can help late fruits to ripen in

colder climates. On the other hand, trees such as Apricots, which are susceptible to early blooming,

sometimes benefit from a colder site, say on a north side of a building, to keep them from blooming to

early and losing their blossoms to winter rains. After choosing the site and spacing desired, lay out the

orchard by putting 5 foot stakes at each tree location to line up and visually determine the planting

sites. Remember that pollenizers, when required, should be within 50 feet of each other, the closer the

better.

DIGGING THE HOLE

The old rule of thumb is to dig a ten dollar hole for a one dollar tree. Dig the hole twice the diameter and twice the root mass of the tree, at least 3‘ by 3‘ for grafted trees. When digging keep the topsoil

and subsoil separate. Loosen the sides and the bottom of the hole. Note that the shovel may ―glaze‖

the sides of the hole, especially in clay soils, leaving a hard, compact surface that is impenetrable to

young roots. For this reason it is always advisable to fracture the sides of the hole when filling in.

AMENDMENTS – Placing too many goodies in the hole, such as manure or compost, can create an

environment that the tree roots never venture out of. The best amendments are low bulk sources of

minerals, such as bonemeal, soft rock phosphate, kelp meal etc. Mix these with the topsoil, to be

placed in the bottom of the hole, where most active root growth will occur.

PRUNING AND PLANTING



If your tree has a bud union, face it north, or on the opposite side of strong prevailing winds.

Carefully note where the soil line was o the plant so that you can plant it a t the same depth as it was

grown, or slightly deeper. With grafted trees it is important that the graft union be 3‖-6‖ above the

soil. Prune off any damaged roots just above the break, as well as crossing roots or unusually long

roots. If there is a definite taproot (typical of nuts) leave this longer than the side roots. Remember

that the tree lost several roots when dug, and this must be balanced by top pruning, so that the rootscan feed the branched without strain. Trees under 4 feet are usually cut back to a 3 foot single whip,

cutting back any side branches and about a third of the top. Be sure to leave a healthy, plump bud at

the top of the tree, cutting 1/2 inch above it. A rule of thumb: branched trees and multi-stem shrubs

should have 50% of each twig pruned off.

When ready for planting, put about 1/3 of the topsoil mix in the hole and place the tree in, spreading

the roots. Often a mound of soil at the bottom is useful for keeping the roots spread out. Avoid

placing any weeds or green plant material in the hole – they emit methane gas when decomposing,

which does not agree with young roots. Put the rest of the topsoil in and tamp lightly. It is important

to eliminate air pockets and ensure that the roots are in good contact with the soil. This can be

achieved by puddling the tree roots with large quantities of water. Fill the hole and let it soak in,

gently wiggling the tree and poking the mud with a stick to eliminate air bubbles. After the water has

soaked in, fill the rest of the hole with the subsoil and tamp it firmly with your feet, keeping the stem

upright.

CARE OF YOUNG TREES

Proper care is essential during the first few years of a tree‘s life, with the first season being the most

crucial. A healthy soil and vigorous growth is the best insurance against pests and diseases. Be sure

you can weed and irrigate regularly during the summer, at least 1‖ of water per week (drip works

great). Note that standard and semi-standard trees can usually be weaned to dry framing as they

mature, but supplemental water is necessary to get them established. Top dress in the spring with

compost or aged manure at the dripline. Paint the trunk of all young trees from an inch or two below

the soil level up to the first branches with white or light colored interior latex paint that has been

thinned with equal parts water. This is especially important in hot summer areas, to protect the tree‘s

young sensitive bark from sunburn and flathead bark borers. During the growing season, remove any

sprouts from the rootstock. Cultivating or mulching the ground in a minimum 2 foot circle around the

tree will greatly help the growth. Keep mulch and organic matter away from the tree collar (where the

trunk meets the soil) to avoid collar rot. When necessary, use screening to protect tree roots from

rodents.

http://www.sandybarnursery.com/care-of-bareroot-trees.htm

3. Potted Fruit Trees

Ken Priddy

A few years ago I was forced to start growing my apple trees in pots when I moved to an apartment.

Although three of my trees are fruiting this year, most of them are only one year old grafts All my

apple trees are grafted on M 27 or EMLA 27 rootstock I have not tried any other rootstocks such as P

22.






Although my three year old trees are in five gallon pots, forty trees grafted in the Spring of 1992 are in

one gallon pots. I plan on putting them in larger pots next year. It is critical to keep potted trees well

watered, especially with fruit on them. I think my success with trees in one gallon pots is because they

are shaded about half the day. I water them one and sometimes two times a day.

Five gallon pots seem to work well for my older trees which are starting to fruit. I think pots larger than five gallons would work even better for apple trees. They would need to be watered less and

would probably produce more fruit. I am using five gallon pots or smaller for the following reasons:

The pots cost less.

They take less soil to fill them.

They are easier to move than larger ones.

Another important factor in growing potted fruit trees is fertilizer. The trees must be fed regularly or

they will barely grow and will not produce fruit. Regular fertilizing with small amounts of Rapid-Gro

or fish fertilizer keeps my trees healthy and prevents fertilizer build up in the soil. Although moss has

grown on top of the soil in some of the pots, it has not been a problem yet. I have heard that fruit trees

need to be repotted every three years, but I won't repot that often unless problems occur.

Extreme cold such as we had in the winters of '88-'89 and '89-'90 can prove fatal to potted fruit trees.

All my trees in gallon pots were killed in '89-'90 by having their roots frozen. Trees in larger pots

fared better, but I only had a few and don't have much data. I recommend protecting potted fruit trees

from extreme cold during the winter. Putting the pots up against a building and in a spot protected

from the wind helps protect them. More protection may be needed. If the pots are under the eaves,

make sure they don't dry out. As of yet I haven't figured out why the roots of two apple trees died this

spring.

Finally, I recommend very limited or no pruning the first three years for apple trees on M 27. Some of

my apple trees which I pruned way back after one year of growth did not grow much the next year.

If you don't have much space for growing fruit trees, or if you are disabled as I am, I hope you will try

growing a few trees in pots.

http://www.homeorchardsociety.org/article/9/

4. Apple cross-polination

As apples are so widely grown and have been so closely studied we know lots about their sex lives.Almost without exception apples need a female parent and a male pollinator. Though both male

(stamens) and female (the pistil) parts occur on the one tree and even within the same blossom, apples

are unable to pollinate themselves. They require pollen from another apple variety to achieve

successful fertilization. We also know that bees and to a lesser extent a few other insects (beetles,

moths etc) are responsible for transferring the pollen from one variety to another. A honeybee may

make dozens of trips daily through the orchard in full blossom and visit hundreds of blossoms. As they

visit the flowers collecting nectar and pollen to feed their brood, pollen adheres to their hairy bodies

and subsequently rubs off onto the sticky tips of the pistils. When this happens, pollination is effected.

We have also observed that bees prefer to confine their flights to one group of trees so they pollinate

well in hedgerows or groups of trees actually growing together. On the other hand the isolated






roadside wildlings growing around here are always loaded with fruit, so the bees are not neglecting

them either.

Apples are self sterile and need pollen from other apple trees to mix and maintain a rich general

diversity in their offsprings. Of course we are interested in (and tempted by) the sweet and aromatic

flesh surrounding the seeds and pay little attention to the seeds themselves. By discarding the seed andspreading it around we are doing our job in nature‘s scheme of things and it is interesting to note that

despite the best efforts of plant breeders, still many of our new varieties are the result of chance

seedlings!

In the home orchard there is seldom unsatisfactory cross pollination. 3 or 4 varieties growing together

will give a good overlap of flowering times and it‘s more usual that apples are too prolific and set far

too many fruit and have to be thinned (remove 3 of every 4 fruit if you can bear to do so), rather than

the scenario in which they don‘t set any fruit at all.

There is a group of apples however, known as triploids. These produce no pollen and put all their

energy into producing usually big and large quantities of fruit. Among the list of triploids are Belle deBoskoop, Blenheim Orange, Bramley‘s Seedling, Calville Blanc D‘Hiver, Cat‘s head, Gravenstein,

Jonagold, Mutsu, and Ribston Pippin. They need other apple trees (diploids) to give viable pollen for

fertilization and more attention should be given to their requirements.

It is not always so that varieties fruiting early in the season also flower early. Apples flower over a

period of about a month from late September and there is a good overlap of flowering times to secure

good cross pollination. And in the end - apples are as bound up by their sexuality and need to

reproduce as we are and they want to and are busy doing it!

So if you plant 3 or 4 varieties (very early, early, mid season and late maturing) I‘ll guarantee that you

will not have any cross pollination problems.

http://www.woodbridgefruittrees.com.au/woodbridgefruittrees/articles/158-apple-cross-

pollination.html

5. Woolly Aphid and Rootstocks

We have had enquiries lately about rootstocks resistant to woolly aphid and this article is in response

to those enquiries.Woolly aphid is a very destructive insect pest that almost wiped out the apple

industry here in Tasmania and in South Africa in the early 1900‘s. Before the time of modern

pesticides, orchardists were forced to use poisons based on arsenic and nicotine to attempt to control

this pest.... with varying results.

Woolly aphids are a tiny burrowing insect with a protective white fluffy cottony covering. Severe

infestations look as though there is cotton wool on the branches of the tree.They lay their eggs in the

bark of the host and can reproduce quickly, and part of the life cycle is a winged insect allowing them

to spread. They suck sap from young branches, buds, leaves, even roots, and can quickly weaken the

tree.They also live below ground feeding on the roots.An infestation in rootstock beds is particularly

damaging even disastrous.

Aphid sucking sap

http://www.woodbridgefruittrees.com.au/woodbridgefruittrees/articles/158-apple-cross-pollination.html







Mass woolly aphid infection in apple growing areas in the late 19th and early 20th century prompted

the use of Northern Spy as a rootstock. It was well known that this American apple variety was

resistant to woolly aphids and the apple industry quickly changed to using this as a rootstock. Unfor

tunately it wasn‘t so successful as far as rootstocks go - the resulting orchard tree must have very good

soil conditions, often has a one-sided root system, can be short lived and not easy to propagate.

Realising the short comings of Northern Spy the East Malling Research Station in the UK started a breeding program to produce a better woolly aphid resistant rootstock.They crossed Northern Spy with

other resistant varieties (eg Ben Davis, Winter Majetin and M793) to produce some 4000 rootstocks to

be tested. Only 15 survived the rigorous tests and from those only 2 really became widely used -

MM106 and M111.

MM106 became the standard rootstock of our apple industry for 50 or more years. It had and still has

all the attributes of an excellent rootstock. Comes into fruit early, does not sucker, produces well in

propagating beds, high quality fruit and semi-dwarfing in size. M111 (or M one eleven as it‘s known)

is a little more vigorous, withstands drought and poorer soils. It‘s not quite as precocious as M106.

In the 1960‘s Dutch and Belgium apple growers started playing around with dwarfing rootstocks,

particularly M9.The combination of M9 rootstock and the variety Jonathan became the standard by

which orchards were set. Amazingly precocious and prolific, these intense orchards were producing

twice or even three times more fruit per hectare than ever before. But M9 had problems - it cant

tolerate anything but rich soil, and has a brittle root system so needs support to prevent the tree falling

over. Consequently, many growers switched to M26, a variety introduced from East Malling in 1959.

It is slightly more vigorous than M9, better anchored and served the needs of the industry at the time.

It has become the standard dwarfing rootstock in Europe and Australia. It‘s not sufficiently cold

resistant for colder parts of USA and Canada.

In the 80 years since woolly aphid was such a problem, modern insecticides have also been developed,and it‘s standard nursery practice to keep woolly aphid under contr ol in propagating beds with

vigilance firslty and secondly, systemic insecticides if needed. Consequently woolly aphid at present is

not considered a serious pest of modern well maintained orchards and an outbreak can be quickly and

locally controlled with a systemic insecticide like ROGOR 40. It should be pointed out that resistance

of the Northern Spy derived rootstocks is not passed onto the variety grafted upon them so if an

outbreak were to appear above the graft, it would still have to be treated.

Taking all this into consideration, we decided to go for M26 rootstocks when growing our trees. They

are precious and prolific, very suited to intense growing systems like espaliers, cordons, spindle bush

and ideal for home gardens and small orchards where one can fit quite a few varieties into a small

area. It makes much more sense for the home orchard to grow 3 or 4 small trees with a broad spectrum

of ripening times in the space of one regular sized tree. M26 also produces high quality fruit. Looking

back over the last 15 years or so that we‘ve been producing trees upon this rootstock we‘d like to think

it has been a good choice. It‘s amazing to think that the extensive rootstock breeding programmes

were a response to a little pest only a couple of millimeters long!

If you‘re getting Woolly aphids on your trees, there‘s a range of things you can do.

You can physically squash the fluffy waxy white stuff where the aphids are hiding, although that wont

prevent the tiny eggs that have already laid from hatching, nor treat the ones growing on the roots.



Another approach is to make sure the tree isn‘t stressed - plenty of water during dry months along with

mulch, manure and a balanced fer tilizer. A healthy tree is much more able to resist insect infestation.

Some say growing nasturtiums at the base of the trees can prevent the woolly aphid crawling up.

Ladybugs, hoverflies (larvae) and Aphidius wasp are predators of woolly aphids. They can be attracted

by companion planting - eg Alyssum, Achillea, Lemon Balm, Verbascum, Dill, Coreopsis, Helianthus,Yarrow, Fennel, Coreopsis, Coriander, Foxglove, Statice, Lupin, Scabius, Sunflower. Keeping the

garden well mulched and watered will provide moisture for these beneficial bugs.

Harmless sprays to try include oils: use ECO-OIL (canola oil based with teetree and eucalyptus oil) to

smother the insects and dehydrate and kill the eggs. Similarly white oil emulsion or paraffin oil work

by suffocating the insects in winter months.A lime sulphur spray (can irritate if got on the sk in as it‘s

quite alkaline) in winter months may help kill the eggs between fissures of the bark.

Systemic sprays include: Pyrethrum spray is considered low toxic but can also affect benificial insects.

Systemic spray exist that control wooly aphids. We do not recommend these because of their toxicity.Confidor (BAYER / YATES) is applied as a soil drench and absorbed through the roots of the plant,

considered low toxicity but has a withholding period of up to 3 weeks before fruit is picked after

treating. Alleged to kill bees. Rogor (SIPCAM) is a systemic organophosphate insecticide used mainly

in an agricultural setting, and unavailable in most domestic nurseries because of it‘s potency and

toxicity. It works well, and there is a withholding period before the fruit can be harvested of at least 7

days. Again, this stuff is toxic.

http://www.woodbridgefruittrees.com.au/woodbridgefruittrees/articles/175-woolly-aphid-and-

rootstocks.html

6. What are dwarfing fruit trees? How to make a prolific orchard

The Greek historian Theophrastus writing in about 350 BC recorded that Alexander the great sent

home to Greece from Asia minor plant material of the "Spring apple", a dwarf, self rooting form of

malus. This message from almost 2500 years ago is the first reference to what became known as the

paradise apple. From the many subsequent references that survive, it appears that the Romans too were

conversant with grafting and found dwarfed apples fitted very happily into formal Roman garden

culture. By these means they were widely disseminated throughout the Roman Empire. There is

conjecture that the name "paradise" is connected somehow to the garden of Eden. In any case, what

was started by the Romans was continued by the monastery system in Europe during the middle ages,

and by the time of the Renaissance, paradise rootstocks were firmly established throughout Europe,

especially in the gardens of the aristocracy and the church.

By 1900 when fruit growing was becoming more specialised and scientific, it was realised that there

was a great confusion in the rootstock materials found in the nursery trade. Research began at East

Malling research station in Kent to standardise the available material and find those most suitable for

orchard production. That is why virtually all our clonal rootstocks have a prefix EM (East Malling)

often shortened just to M or later MM (Malling Merton). The EM rootstocks were mostly collected

throughout Europe and the MM rootstocks were the result of controlled crosses between many species

of malus both wild and cultivated.

Starting at EM 1 the research continued until 1952 with EM 3461! This amount of research, dedication

and attention to detail is mind boggling to a mere apple grower like me. Well - one may ask, why all

http://www.woodbridgefruittrees.com.au/woodbridgefruittrees/articles/175-woolly-aphid-and-rootstocks.html







this fuss and work to produce dwarf apple trees? Why not just produce nice big ones as nature

intended?

It‘s all to do with control and quality. Small growing trees are very precocious starting to bear fruit

usually in their second year (if you grow them well that is). They are easier to spray and prune and

harvesting is more efficient. Many varieties of apples have a biennial habit - that is they tend to bear ahuge crop of fruit one year and have a rest the next. Varieties on dwarfing rootstocks are much easier

to thin in the "on" year thereby not stressing the tree too much and so to bear more regularly.

Work done at our research station here at Grove in Tasmania also showed (very important this!) that

fruit quality on dwarfed stocks was much higher than on seedling stocks and that the fruit stored and

transported better. This was due to available calcium supply both within the tree and the fruits

themselves.

Also in our Australian environment dwarfed trees can easily be protected from birds and wildlife

predation (see my espalier article) . For the home gardener it‘s perfect to grow 4 or 5 dwarf trees,

providing fruit over 4 or 5 months in the space of one large tree. Some varieties such as Gravenstein,Mutsu, Jonagold and Blenheim Orange (these are triploids and give no viable pollen) are notoriously

slow to start bearing on normal rootstocks - up to 9 years - whereas on dwarfing rootstocks they are

precocious and begin to flower in their third year.

In Australia the move to dwarfing rootstocks was very painful for the apple industry, and even today

some orchardists continue to grow trees on seedling rootstocks. This is because of several reasons: -

seedlings are much cheaper to produce - dwarfing stocks cannot cope with replant situations like

seedlings can - dwarfing trees are planted at much higher density, so instead of 150 - 200 trees per

hectare, an orchardist may have to buy 1000 trees - a big cost difference.

Anchorage is not as good in dwarf trees and cropping is heavier, so wires and systems have beendeveloped to support the trees.

The home garden fruit tree business in Australia has focused on big vigorous looking trees with big

glossy labels in garden centres with staff seldom conversant with fruit tree culture. The trees have to

sell themselves - and we all know that bigger is better. In reality the opposite is true.

This is what YOU should do:

Firstly don‘t buy big trees in garden centres.

Keep pruning to an absolute minimum (difficult for a nation that just loves pruning...)

Tie down upright growing branches rather than cut them (upright branches grow leaves, sideway

branches grow fruit)

Let the tree crop early. DON‘T do as the books say and remove all the fruit for the first years. Leave

some fruit. It pulls the branches down and inspires you to give your little tree even more attention.

Don‘t start to irrigate trees in spring until you feel it‘s really necessary.

Early irrigation makes more vegetative growth than fruit.

Don‘t over fertilize trees. High nitrogen levels are a recipe for growth vigour and low fruit quality.Over fertilisation also seems to cause calcium deficiency. Calcium is deficient in most Australian soils



and apples have trouble taking up calcium from the soil. Many orchardists use calcium sprays. Glassy

core and bitter pit are caused by a lack of calcium.

In short: for a productive home orchard: buy dwarf trees, plant them close, don‘t let weeds compete,

keep pruning to an absolute minimum, keep branches horizontal and don‘t fertilize heavily.

http://www.woodbridgefruittrees.com.au/woodbridgefruittrees/articles/174-what-are-dwarfing-fruit-

trees-how-to-make-a-prolific-orchard.html

7. Minimise sun damage

The extreme heat a couple of seasons ago — and the heavy fruit losses that resulted — should not be

forgotten because now is the time to protect fruit from such damage.

The last 12 months of mild temperatures and plenty of rain is a stark contrast to the 2008 – 09 and

2009 – 10 seasons where we experienced low rainfall and extreme temperatures resulting in significant

levels of sunburnt fruit.

There was very little requirement for sunburn protectants last season and it will be interesting to see

what this summer brings.

Lessons learnt from the 2008 to 2010 seasons

Trees near headlands were often most affected.

Fuji and Granny Smith appeared to be the most severely damaged varieties. Gala and Pink Lady™

were less affected.

Fruit on the west side of trees was damaged more by sunburn than on the east side.

Unconditioned fruit suddenly exposed to the sun‘s heat were at high risk of solar radiation injury.

Summer pruning, late hand thinning and the removal of sunburnt fruit resulted in previously protected

fruit becoming sunburnt.

Blocks with a healthy inter-row, as a opposed to dead grass, did better.

Hail netting was helpful in reducing damage to fruit by solar radiation but hail netting alone was often

not enough to prevent sunburn.

Fruit that suffered the least amount of sunburn had sunburn products applied at regular intervals in

addition to being covered by hail net.

Dwarfing rootstocks provide even light distribution through the canopy, but they increase the risk of

sun damage to fruit cells under extreme weather conditions.

Weather conditions that favour fruit injury to sunburn include cool weather prior to high temperatures

in combination with low humidity for extended periods of time.

Sunburn products

There is no new product of note: Parasol, Surround and Raynox are still the main sunburn protection

products.

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Parasol is an easy to use liquid that leaves a fine protective particle film on the surface of fruit that is

removed easily in the packhouse.

Surround is a fine white powder that also leaves a protective particle film on the fruit surface. Some

orchardists have had success using the spreader Du-Wett to improve coverage.

Raynox is a liquid which leaves no visible residue on fruit and does not wash off in wet weather like

the other products. So it has a better fit for use in conjunction with evaporative cooling systems.

Timing

Correct application timing is essential to optimise protection. Timing applications with the fruit

growth-rate curve has given the best results — apply more applications early in the season when fruit

growth rate is highest, and less frequently approaching harvest.

Spray application

Applying sunburn products from above is the preferred method, rather than attempting to apply themthrough a traditional airblast sprayer.

Good options include tower sprayers, or attaching a boom to airblast sprayers that extends to the

height of the trees.

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8. Practical ICM at its best

Establishing a new citrus orchard on the windblown sand hills in the southern Riverina of New South

Wales is a challenge.

Location Mowbray Citrus, Berrigan NSW.

Problem Wind, and blown sand damaging newly planted trees.

Solution Integrated Crop Management (ICM) using local ‗weeds‘ as windbreaks.

It‘s a test of the persistence and endurance of the trees, and the resourcefulness of growers against the

challenges of the environment.

The sand hills in the area are quite high with deep gullies. The sands have extremely low organic

matter, low water-holding capacity, and poor nutrient retention.

The sands are a good medium to support the plant, but offer very little else.

Soil reclamation

The sand hills grew fresh market potatoes for many years, so soil reclamation was the first step in

establishment.

These sands were maintained at low pH for disease control, and the long-term use of urea fertiliser with no other cropping, resulted in a strong acidic soil profile.

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Lime and gypsum were applied down the tree lines; double drip lines and a state-of-the-art fertigation

system were installed. The first trees were planted in March 2011.

The sand hills are very prone to wind — hence sand blasting any crops — especially around the spring

and autumn equinox.

To overcome the winds and damage from windblown sand, a range of crops such as millet and

sorghum were grown to act as wind breaks.

However, as we all know, it rarely rains at the right time, so these crops never had the rains early in

the season for emergence of the crops and they didn‘t establish to develop as windbreaks.

On the exposed tops of the sand hills, the crops died out completely and didn‘t even provide any

ground cover.

Clever use of the environment

The alternative (shown in the images) illustrates the clever use of the environment.

While Paterson‘s curse, also known as salvation Jane (Echium plantagineum), may not be seen as

natural, it is an established weed and part of the local landscape.

By using a ‗weed‘ that tolerates the conditions and grows without irrigation in a most difficult climate

(trees are drip irrigated so no irrigation water reaches the sward between the rows), the winds pass

over the top of the citrus trees and are protected from the blown sand.

This system will give protection to the trees for two to three years — until they are well over the height

of the Paterson‘s curse.

Weed control & benefits

The problems that the Paterson‘s curse produces, have been managed with a covered treeline sprayer

for treeline weed control.

The Paterson‘s curse also provides an insectary for their biological controls that have been released.

Seven insects that attack all stages of Paterson‘s curse have been released in Australia.

There are disadvantages to having such an important weed, however, in this situation the advantages

are much greater than any disadvantage.

Spectacular biological activity

While taking pictures of the wind break created by the Paterson‘s curse, I noted some spectacular

biological activity.

There were sporadic armyworm caterpillars in the young citrus trees giving some — but not

significant — leaf damage.

In the sward of Paterson‘s curse, there were huge numbers of armyworm caterpillars and platoons of

sand wasps controlling them.

Sand wasps



The female sand wasp stings and paralyses her prey. She then carries the caterpillar to the nest she has

dug in the sand and places the immobilised caterpillar inside the nest where an egg is then laid.

The developing wasp larva feeds on the paralysed caterpillar prey — a great example of IPM in

practise.

In the image above, sand wasp nests can be seen dug into the sand along the treeline and around the

weeds.

There were a number of different wasps, but the sand wasp was the most common.

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9. Roots —the ‘brains’ of the plant

The worldwide Stoller Group has a mission to look at the factors that influence plant growth, work out

how they are impacted by environmental factors, (such as the weather), and then take measures tominimise that impact.

Stoller‘s Research Director, Dr Albert Liptay spent a week in Australia recently, planning the 2013

R&D program with Stoller‘s Australian technical team.

While he was in here he took time out to update the locals on the latest thinking. As the foundation for

this, he reminded the group about the function of tree roots.

Tree roots

The roots are the control centre for the plant. The new root hair tissue that has a life of about 14 days,

is the site where water and nutrients are absorbed, but more importantly, the site where four of the five

main plant hormones are produced. These hormones form the messaging system for the plant.

The root hair tips are especially influenced by temperature. If the root hairs are healthy and

functioning then the rest of the plant is better equipped to cope with the weather.

If the roots are deep, then the temperature and the general conditions for the roots are more consistent.

The brains of the plant are protected deep in the ground and are somewhat immune to the impact of

ambient temperature changes.

Deeper roots, better protection

If you can follow the logic above, then you must agree that we want deep root systems that are

protected from the environment.

In this way the plant‘s control centre is not exposed to stresses that would have an impact with a

shallower or weaker root system.

Stoller Australia has a number of treatments that can help with deep functional roots. Regular soil

treatments applied to the soil and watered in or applied through the micro irrigation can help the nature

of the root growth.

Root enhancement products

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Most of Stoller‘s specialty root enhancement products incorporate calcium and co-factors.

These components act in a synergistic manner and trigger new root tissue development with each

application, as well as deeper root system with greater mass.

As we mentioned above, root hair tissue (brains of the plant) only live for 14 days, so we need to

continually trigger new root growth.

Stoller‘s RootFeed is a multinutrient soil treatment that supplies amine nitrogen, calcium and

magnesium with co-factors. This unique combination has both a nutrient and hormone balancing effect

on tree growth leading to a more robust root system.

Another product called Action 5, performs a similar function without the amine nitrogen content so is

an ideal supplement to a regular fertiliser program.

With the root system (control centre) in a safe and stable environment below ground, the plant is able

to tolerate weather variations and make adjustments to the plant functioning pattern despite the

environmental variations and threats.

―It isn‘t rocket science‖, explains Doctor Liptay, ―but looking after the control centre (roots) can keep

the whole factory (tree) in production and help the tree maximise the realisation of its blue print (or

genetic potential).‖

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10. Innovative non-destructive fruit maturity meter

Supply of consistent quality fruit to consumers is one of the major challenges facing the Australianfresh fruit industry.

An important factor affecting fruit quality is maturity and it is essential to maintain optimum maturity

at every step in the chain from harvest to consumption.

Despite being a major driver of fruit quality it is not easy to measure and maintain maturity at

optimum levels from farm to consumer.

Fruit maturity is directly linked to most of the variables that comprise fruit quality such as total soluble

solids, total acidity, flesh firmness, fruit colour and starch content.

These are normally determined destructively on a sample of fruit which is not always representative of

the variability of fruit batches. There are currently only a few instruments that allow non-destructive

measurements of specific fruit quality attributes such as soluble solids and flesh firmness.

Equipment that is commercially available commonly uses visible (vis) and near infrared (NIR)

spectroscopy and acoustic technologies respectively. These devices can be used in the field or on

packing lines, but can be expensive, relatively slow and generally require frequent, complex

calibration on a large number of fruit to be useful.

Non-destructive fruit maturity meter

Recently, a new non-destructive fruit maturity meter was developed in Italy and is being tested by DPI

Victoria.

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The DA Meter (Figure 1) is an innovative instrument for non-destructively determining fruit maturity

by measuring the decline in chlorophyll content immediately below the skin during ripening.

Developed and patented by Professor Costa and his team at the University of Bologna, Italy, the DA

Meter is a portable spectrometer which can accurately monitor fruit maturity.

A maturity index is developed for each fruit variety by calculating the difference in absorbance (DA)

between two wavelengths (670 and 720 nm) close to the absorbance peak of chlorophyll-a and

comparing this with fruit ethylene production.

The DA value is strongly correlated with ethylene production of fruit, which is an indicator that

ripening has started.

The DA decreases in value during ripening of the fruit, until it reaches a minimum value when fruit

ripening is complete.

Potential use for DA values in stone and pome fruit

Each fruit species and cultivar has specific DA values according to the different phases of maturation.

Consequently a set of reference indices are required for each cultivar, but once established they can be

used year after year as DA values are not affected by agronomic or postharvest practices.

This is a major advantage over other non-destructive technologies which require at least annual re-

calibration.

Pioneering research by the University of Bologna team indicated that the DA Meter exhibited great

potential in the peach production chain. In the field, it was used to establish the optimum time to

harvest and in the pack house the DA value was used successfully to accurately sort fruit according to

maturity.

It can also be used during the cold chain to establish maturity changes over time.

In another study, the potential of the DA Meter was assessed for segregating peaches and nectarines

into consistent quality classes based on shelf life and consumer preference attributes.

The DA easily separated fully red peach varieties into consistent classes which had a high correlation

with ethylene production rate, postharvest ripening behaviour and consumer acceptance.

Other research has shown that the DA Meter is a reliable tool for monitoring on-tree apple ripening to

establish the optimum harvest time to maximise fruit storage life and quality.

Research needed to fully utilise potential

A great deal of additional research is necessary to fully utilise the enormous potential of this

instrument.

Assigning DA values to each stage of the chain is one step required for adoption of the DA technology

by the horticultural industry. Further research is required to identify the correct DA value ranges for

each step.



To optimise maturity and quality during the entire fruit chain the DA Meter can be used as a tool to:

optimise crop load and other agronomic practices to obtain a consistent, high quality crop

reduce the number of picks and reduce fruit variability

identify the optimal picking window

monitor and quantify maturity of stored fruit and at any specific time the shelf-life potential of the fruit

sort fruit according to maturity, thus guaranteeing optimal, predictable and consistent storage quality

whether using normal air, CA or 1-MCP

increase market flexibility by being able to measure and predict suitability of fruit for supplying local,

national or export markets and minimising variability in shelf life and market performance

enable retailers to rapidly and accurately measure fruit maturity to mange inventory thus presenting

produce consistently at the required consumer preference.

Fruit maturity could become the quality parameter that allows full integration of information between

practitioners at each step in the chain based on an exact reference value provided by the DA Meter.

Monitoring fruit maturity using DA values along the value chain will allow the identification of best

management practices at each step which will reduce losses due to variable quality and will increase

efficiency and profitability.

Knowing the ideal DA value that correlates with quality preferred by consumers will permit real time

correlation at each step of the chain allowing fast decisions on the future of each fruit regarding the

remaining shelf life and consequently the preferred market. This will increase consumer satisfaction

and return sales.

Consistent, simple value chain protocols can be created and whole system models implemented to

provide a high level of agility for the Australian industry and the ability to respond rapidly and

strategically to market contingencies and outside pressures both locally and internationally.

Testing under Australian conditions

The Department of Primary Industries Victoria based at Knoxfield has recently acquired a DA Meter

and is testing its efficacy on stone and pome fruit varieties under Australian conditions.

Close collaboration with the University of Bologna team has allowed data exchange and frequentdiscussion to further develop this revolutionary instrument.

Currently, DA value ranges at each step of the chain for key varieties are unknown and DPI is

planning research projects which will help identify them. As a start, the DA Meter has been integrated

as a standard measurement at harvest time in current and future DPI pome and stone fruit projects.

Future research projects cover all steps in the value chain including fruit production, harvest, handling,

storage, fruit composition and quality and consumer preferences.

However, considerable industry investment and collaborative effort will be required to cover the broad

range of possible fruit species and variety.



Preliminary results

Preliminary results in Australia indicate that the DA Meter is very effective for monitoring and

quantifying the effects of irrigation on Royal Gala maturity at harvest (Figure 2) as well as measuring

fruit maturity at harvest to predict storage life and susceptibility to chilling injury of mid season peach

and nectarine varieties.

Full adoption of the DA-Meter will help project the current Australian horticulture supply chain into

the 21st century, transforming it into a powerful value chain leading the world wide horticultural

market in term of volume and quality.

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