Most of our practices are aimed at increasing biodiversity. We hope to achieve greater biodiversity at many levels by
- incorporating animals (geese,chooks, pigs, bees etc) into the system.
- increasing the range of fruit crops grown.
- increasing the varieties of apples and peaches grown.
- establishing belts and borders of native vegetation to encourage more diversity of insects, birds, etc.
- trying to increase microbiological diversity in the soil and on the plants themselves.
We believe greater biodiversity will help us create a more balanced
eco-system, less suceptible to the agronomic risks associated with monocultures. This also helps to spread our financial risks.
1. Pests and Beneficials
Codling Moth and Light Brown Apple Moth are controlled by "mating disruption". This involves placing dispensers in the tops of trees that saturate the air with the scent of the female moths, making it difficult for the males to locate the females.
Light Brown Apple Moth is a native insect. The large number of predatory wasps that occur in the native bush prevent a build up of large numbers of Light Brown Apple Moths in bushland. Monocultures such as vineyards and orchards support few predatory wasps and commonly see huge numbers of Light Brown Apple Moth. We plan to plant belts of native vegetation throughout the orchard next winter.
codling moth
light brown apple moth & grub
Heliothis and looper caterpillars attack fruitlets in November and December. The hole visible below the looper in the photo will appear as a raised wart on the mature fruit. The caterpillars are controlled by spraying Bacillus thuringiensis (Bt). This is a bacteria that infects only the digestive system of caterpillars.
looper on fruitlets
Lady birds sometimes appear in large numbers on the stone fruit trees in late spring and summer. They have the ability to suppress aphids before the aphids get out of control.
ladybird on young peach leaf
Woolly aphid are now almost impossible to find in our orchard. We introduced the tiny parasitic wasp Aphelinus mali in the mid 1990's, and woolly aphid are no longer a problem.
parasitic wasp
Garden snails have not been a problem in our orchard since converting to organic practices. Control measures are no longer necessary. Previously they caused significant damage to blossom in October.
snail on apple tree
Weevils likewise have not been a problem in our orchard since converting to organic practices. Control measures are no longer necessary. Previously they would build up to damaging levels, eating the skin of the small apples in November and December.
weevil
Birds. Large flocks of crows have been the main bird problem at our orchard. We do whatever we can to discourage crows - an electronic bird scarer, backed up with the occasional blast from a shotgun
We have a small resident population of Crimson Rosellas. We are happy to share and we deliberately leave a few apples on the top branches for these birds.
musk lorikeets enjoying pink lady left on the tree late in the season for juice. They are definitely not interested in sharing with us!
Spiders catch and eat the moths of apple-eating grubs, and we appreciate their work. We have many different species, some building webs that span 4 metres between the tree rows. Even in winter, there are multiple small webs in every tree, clearly visible on a dewy morning.
Tree frogs are also carnivores, working in tandem with the spiders to eat caterpillars and moths interested in damaging our apples. They are often found when we are picking the fruit in late summer and autumn, as they tend to shelter amongst clusters of fruit in the centre of the tree, well hidden from birds and enjoying the little pool of rainwater or dew around the fruit stalk.
Chooks are terrific insect control. When we decided to grow organic stone fruit, we knew it would be impossible without doing something about grasshoppers, earwigs and weevils. Chooks have the ability to turn insect pests into an organic fertilizer before they can damage the crop, and free range eggs are a handy byproduct. Why spray insecticides, purchase fertilizer and purchase eggs?
stone fruit trees, isa brown chooks, maremma dogs and red gum on a winter morning 2010
Dogs are needed to protect the chooks (and geese sitting on eggs) from foxes. We have two Maremma dogs, who do an excellent job (most of the time!).
Pigs are nature's rotary hoe. We have two Wessex Saddlebacks, who are very useful when we need a patch of ground turned over. Even large tussocks of phalaris are no match for our pigs. They are also rather fond of the apple pommace left over when we have made juice. Next year we hope to enjoy some apple flavoured pork, courtesy of their progeny.
Black Spot (or Apple Scab) can be an absolutely devastating disease for apple growers, and its control is particularly challenging for organic apple growers. While the use of copper hydroxide, wettable sulphur and lime sulphur are permitted under organic certification standards, we have been looking at alternatives in the interests of tree health and fruit quality.
A few years ago we tried compost tea for Black Spot control. It was a total disaster two years running with 100% damage on those rows sprayed. We wonder if the process of "composting" favours soil dwelling organisms, so we have also tried a "non-composted tea" brewed from leaves, bark and twigs from our old house orchard. These trees have never had any form of fungicide applied, yet Black Spot damage is insignificant. The aim is to spread leaf dwelling microbes which could potentially out-compete Black Spot.
We are expecting it may take some years to achieve a high level of control, but have treated half the Kalangadoo Orchard.
So we may have quite a lot of second grade fruit for a year or two, but we are quite excited by the project. Our aim is to eventually do away with all foliar sprays and just fertilize through the soil.
The tree line is mulched to a width of one metre with wheat straw every year. Any weeds coming through the mulch are hand weeded. While mulching is time consuming, there are considerable benefits - conserving water, increasing biological activity in the soil, increasing the ratio of fungi to bacteria in the soil (very desirable for tree crops such as apples) and reducing soil temperature in summer.
For the first few years the mulch did a good job of controlling weeds. However as time has gone on, the straw breaks down more and more rapidly which is probably good for the soil but not so good for weed control. So we are currently trialling strip grazing some geese to control weeds.
We have found that geese can do a terrific job of weeding, but there are some management issues :
1. a high stocking rate is needed, and the geese must be moved frequently. We manage this with movable electonet fencing, available from www.allsun.com.au This works well, but is time consuming.
2. geese are vulnerable to foxes when sitting on nests in early Spring. In addition to the electric fence we have a Maremma dog which is very protective of the geese. The drawback is that he loves eating goose eggs!
3. you may have heard that geese just eat grass, but we can assure you that they eat apples too. Even when the apples are green and only as big as your thumb nail! So from about November until harvest we have to get them out of the orchard. We are also changing the tree training in some blocks so there are no apples within a metre of the ground so the geese can remain in these areas all year round.
In 1996 when the first of our apple trees were planted, a dry bank was chosen and the ground was mounded to ensure the trees were not water logged. We believed we were so lucky to have unlimited ground water ! We also believed with careful management and mulching we could probably grow most varieties without irrigation. We were in for a rude shock.
brolga in the rain near our orchard Aug 2010
From 1997 to 2009, we experienced severe drought. A falling water table (we had to deepen the bore from 13m to 44m, and convert half the orchard from sprinkler to drip irrigation), swamps without water (the frog population crashed) and higher temperatures and evaporation (more sunburnt and heat-affected fruit).
But what a difference a year makes! After above average winter rainfall in 2010, the water table has risen, some of the swamps are full, the swans and brolgas are nesting again, tortoises are crossing the roads and the frogs are coming back.
Looking after the soil is paramount. While the necessary nutrients may be present in the soil, it is the presence of microbes which frequently makes them available to the plant.
The ground water flows through a limestone aquifer so the water is high in calcium. It is therefore unneccessary to apply calcium sprays as is done routinely in most other apple growing districts around the world. The trees tend to be vigorous and nitrogen is also present in the ground water, so we tend to avoid fertilisers containing nitrogen.
The trace elements copper, zinc and manganese are of more concern. Regular foliar sprays of fish emulsion/seaweed extract, and post harvest foliar sprays of trace elements are applied. Last Autumn we also applied Sea Minerals solution to the soil. It contains all the minerals found in the sea but with the sodium chloride removed.
Rock phosphate is applied to the soil as required.
We are tending to move away from foliar sprays in favour of ground applications.
We train our trees into a low, narrow hedgerow just over 2 metres high. This gives excellent light penetration and keeps labour costs down.
Some trees are supported by a trellis, depending on tree vigour/rootstock.
7. Pollination
We have a great diversity of insects in the orchard. Wasps, small native bees, flies, butterflies, moths (at night)and honey bees from wild hives in nearby red gums are in abundance in October - so we have found there is no need to introduce bees to pollinate our apples.
However we have one hive for the stone fruit - these flower 4 to 6 weeks earlier than the apples when the weather is much colder and there are less insects about. (And we like to produce a bit of honey for ourselves).
8. Thinning
Thinning the fruit is another major challenge for organic apple growers.
An apple tree in full bloom has "too many" flowers. Less than 5% of the flowers are needed to produce a full crop. If 95% of the flowers/fruitlets are not removed within 4 to 6 weeks of flowering, fruit size and quality will suffer and there will be almost no apples the following season. This pattern of cropping every second year is known as "biennial bearing".
Conventional growers thin flowers and fruitlets with chemicals. We attempt to produce a similar-sized crop every year by reducing bud numbers with heavy winter pruning, thinning flowers with scissors in October, and then removing small fruit by hand through until Christmas. In fact this is a more time consuming and costly exercise than harvesting the crop in Autumn.
What's happening in the orchard now?
Jan 28 2012 Today we picked Tydeman's Early Worcester and Graventstein for the Kalangadoo Farmers' Market. The Summer Red should be ready next week.
We also dried our first two batches of apple for the season this week.
