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Sheryl:  This talk was taped by member Ted Newton who attended Nimbin’s Open House and Garden back in 2013. Led by wild food expert Peter Hardwick, this tour took you around the back streets of Nimbin. Many thanks to Annette McFarlane for typing it up. Edited by Peter and myself.

Peter   Many modern illnesses are often a problem because of modern diet and if we get wild food phytochemicals back into our diet we may be able to treat chronic illness like high blood pressure, inflammation and cholesterol.

The enemy of the urban food forager is the whipper snipper! An unmown path is a bountiful thing with the biggest range of wild foods! One of my favourite tricks when I was young was picking hibiscus and nasturtium flowers when wandering the streets and eating them to shock my friends.

Vary your diet
It’s interesting to look at the diet of some of the preserved bodies of people who have been dug up (eg the Bog man of Denmark – 5000 years old). His last meal was a mixture of 46 different food ingredients. One of the strategies that people can take from this is to eat a range of different things rather than big helpings of one thing. Feasts did occur seasonally (if they came across a bountiful mulberry tree for example), but the range of wild greens that they ate, were often very mixed and not just a single ingredient.

Some were eaten raw and also cooked as stews and wild seeds were mixed into breads. The boiling process with cooking greens often helps to lower toxin levels to a tolerable/safe level.  As a back-up, we also we have the liver to detoxify plant toxins.

Some vegetables can be eaten raw like milk thistle. With boiling, toxins go into the water and you discard the water. Steaming does not reduce the toxin in the same way as boiling, so if instructions say boil, make sure you boil.

Boiling reduces alkaloid levels (especially in black nightshades). Black nightshade in Europe is used to make a cooked salad, but you need to know what you are doing. No one has really investigated them here. I do not recommend eating any black nightshade plants unless you have specific cultural knowledge (like people from Cypress or Greece) on preparation and consumption of this wild green. This is critical with toxic greens such as these.

Black Nightshade
The shoots of black nightshade can be eaten if boiled to remove alkaloids, but please note that steaming would not achieve the same effect. If references suggest to boil a particular wild food, be sure to boil it and do not substitute steaming.

Carrot weed or Wild Celery
Carrot weed has a really good flavour, but like all weeds it can be bitter following long periods of dry weather.  Harsh growing conditions can make the flavour a little bit stronger.  It is really rich in flavour and nutrients. This introduced weed is rich in good phyto-chemicals and has anti-cancer properties. You can eat the roots, flowers and seed heads of carrot weed. Chop it up in scrambled eggs or add it to salads as an alternative to parsley.

Chickweed
Chickweed is tenacious and I love it. I use it in salad and also cook with it. Environment will affect how it grows. There are three types of chickweed, Tropical chickweed (glaucous green) is poisonous, but medicinal. Mouse-eared and common chickweed are edible.  Scarlet pimpernel looks like chickweed but is poisonous.

Clover
Nice to add to a salad, (flowers and leaves), with sour thistle and celery and nasturtiums and chickweed. But look out and avoid any black mould on leaves when you are harvest.

Dandelion
Dandelion has anticancer properties. There is sound scientific research to support this. It is a fantastic medicinal herb. It is a bit bitter, but you can eat them raw. You can also cook it. Dandelion has a single flower stem and the cat’s ear has multiple flower heads. Cat’s ear leaf is also more coarse and hairy. That is how you can tell the difference between them.

Dock
Yellow curled dock is a great plant. The seed heads are like little hearts. Swamp dock is lower growing. All docks are edible, but all contain soluble oxalates, so boil them up and the oxalates will go into the water. They have found the seed of docks in prehistoric man. Was it just contaminated in their spelt or other grains?  Some people seem to think that it was deliberately included. The seeds are very high in tannins – including quercitin that you buy from the chemist as a supplement. It is probably in the leaves as well.

Docks have three uses – roots used as medicine, leaves as a spinach (boiled for about 5 minutes) and the seed/seed heads you can mix with your bread or in a pancake. It gives astringency to the bread. It reduces your blood sugar spikes. If you are oxalate sensitive do not eat docks. The other way of counter this is to eat oxalate containing foods in combination with dairy (for example weed spinach rolls with cheese).

Throw dock seeds into a coffee grinder and it grinds it into a fine brown flour. It is more husk than seed, but it is more of what we need and a really good food source.

Yellow dock root can be roasted and used as a coffee substitute.

Swamp dock is the native dock. It is easy to see the difference between the leaves. The seed heads on this attach to your clothing when they are mature. Yellow dock seeds do not stick to your clothing. This plant contains an anticancer compound in both the leaves and the roots called musizin. The roots of swamp dock are yellow. It seems to have a lower oxalic acid compound, but do not eat a lot of it raw (it can give you nausea). Boil or blanch the leaves.  Use the roots as a medicinal.

Farmer’s Friend
Some people say this is edible but research from early last year indicates it may contain a nasty alkaloid toxin – we are waiting for follow-up research to clarify this. Farmer’s friend does not have a huge history as a food plant. It is used in South America as a medicinal. Comfrey has a similar toxin and should not be eaten. Some things are toxic no matter how little you eat ( comfrey and bracken shoots). As we learn more about phyto-chemistry in wild foods, we discover more about these plants and our ideas of on what can be eaten will change.

Madiera Vine
It is a local weed and you can eat it. It is related to Ceylon spinach. It is a garden escapee. Be careful when harvesting, never spread it around or it may escape into your garden or the surrounding environment. That is a risk with some of these weeds.

It is said to have been used as a laxative. Cook it up/boil to prepare. As a general practice I don’t like to eat huge quantities of a single wild green species. My strategy is to eat a mixture, so that you do not get too much of any one thing. Eat a range of things not big helpings of one ingredient.

I don’t eat Madiera vine raw. I boil it lightly, drain away the liquid and eat it as spinach. There is recent research from Indonesia indicating that Madiera vine is safe.

Paddy’s lucerne or Sida
This plant has medicinal properties and mallow-like qualities (it comes from the mallow family). It stops dysentery. It is strong and bitter in the dry weather and has a yellow flower. You can eat the leaves raw in salads. Most of the sida species are safe to eat.

Shamrock (Oxalis)  It is sour. You may have eaten them as kids. They contain oxalis acid. Just do not eat too much because of the soluble oxalate levels.

Sow thistle
One of my favourites.  You see this around a lot and it is common in gardens. It is a great plant and really nice in salads. The taste is similar to chicory or lettuce. When it is younger the leaves are quite big and lush. It has a yellow flower. It is a really good candidate for domestication (perhaps better than lettuce). It can be a bit bitter, but it is nice mixed in with other salad greens. Be careful with the daisy family, it’s notorious for having sneaky toxins. Do not eat thick head weed. Bracken fern was once thought to be edible. Then they found out that consumption of bracken fern fiddle was carcinogenic, even though this was a traditional part of the Japanese diet. That is why you need to be cautious. Some of the references on what is safe to eat from 20 years ago and now out of date.

Wild mustard/wild brassica
You can eat the yellow flowers on wild brassicas. Wild radish is strongly flavoured. They grow wild in some areas and become naturalised on roadsides. They are full of glucosinolates. Wild brassicas have these compounds in much higher amounts than cultivated greens. It is best to boil brassicas really well.

Nasturtium
Nasturtium has a multitude of uses and is a great garden escapee. Throw it in salads. Seeds can be pickled as capers. They are yummy. I like pickling them in bush lemon juice and salt and some spices (like Dorrigo pepper)

Shepards Purse – This is in the brassica family. It is a small, subtle herb and comes up a lot in cooking in Celtic/European history along with yarrow. It is used for food and medicine. You can eat the leaves and the seeds. I have not tried the seeds.

Lots of the weed seeds were distributed via ballast bags filled and pack into boats. The soil was tipped out at the docks and that is how the weeds were spread.

Plaintain
There is a broad leaf plantain and a narrow leaf one. They are both edible anti-inflammatories.  They were a staple of Celtic people. They have a mushroom flavour and a slight bitterness. I chop it up mix it with the leaves of clover and dock, boil them put them into a pie or a stew. The younger leaves are more tender. Just use a small amount. They are said to lower cholesterol. Psyllium husks comes from a type of plantain. Comment from participant – ‘The narrow leaf plantain is traditionally used as a poultice’.

Weeds to avoid
Morning glory is toxic (even though wallabies do eat it). Be cautious about bindii – I do not know precisely the toxicologically, but it is related to things like hemlock, so be cautious.  Watch out for fungus on grasses. Wheat grass is edible, but not all grasses are edible. Be careful with jute and do not eat kale every day, especially in drinks. The availability of phytochemicals is much higher in a green smoothie. Try sow thistle in a green smoothie but do not use yellow dock. It is too high in phytochemicals. The potency is so high.

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Soil Nutrition; Organics v Conventional Farming and Tips on Grafting

Components of soil – Soil has four major components: Air – healthy soil has 25% of its volume as air. It is this space where the roots and living matter (bacteria and fungi) are living. Water – in a fully saturated soil 50% of it might be air spaces filled with water (at field saturation it is 25%).

Minerals – 50% of remaining are typically minerals.

Organic matter and living organisms
Avoid digging organic matter into the soil especially loams and clays (more so than sandy soil). Put organic matter on top and let organisms work it in. The average earthworm has 30,000 different types of good bacteria in its gut. Bad bacteria that pass through the gut of a worm are destroyed. Cover crops and green manures should be chopped and laid on the top of the soil. If you turn a green manure in, do so to less than 10cm. Why leave the cut green manure on the surface of the soil? Rapid decomposition in the soil can use up the available oxygen and nutrients, making them less available to plant roots. If you turn a green manure in, do not plant for a minimum of six weeks, but preferably three months. In a hot, dry climate, cover the cut green manure with a light layer of mulch, enough to stop it from drying out. The depth of aerobic bacteria is another reason for not digging organic matter in. Where are the microbes and the biggest number fungi and algae? Over 80% in the first 7-8cm (3 inches) – then 10-15% in the next 25cm (10 inches) – then things get fairly scarce. It is even less in heavy and compacted soil. Why? Plant feeder roots need oxygen and water. The top section of the soil, the aerobic zone is the healthy part of the soil for plant feeder roots where air can get in and out. Plant roots and organisms produce carbon dioxide and other noxious gasses that need to get out of the soil.Once you go past 15-20% organic content in a soil, you tend to magnify fungal diseases and soil borne pathogens.

Plant/microorganism interactions
Plants give away sugar in fruit, nectar and other means. What is sugar? Carbohydrates (carbon, oxygen and hydrogen). Plants can make this easily via photosynthesis. What good is this to the plant? It attracts animals in to pollinate flowers, distribute seeds and can form a protective mechanism for the seed. They also give away sugar through their roots. Of the total amount of starch produced by a corn plant, an estimated 50% is given away via the roots by being traded off with other organisms. The corn stalk is all sugar, starch and cellulose that has come from sugar. What plants do is look to achieve some balance/control of the rhizosphere. This is the area of soil closest to the roots where the interaction between root secretions and soil biology is most pronounced. By trading sugar, modifying pH and oxygen tension they are trying to influence all the organisms around the root system. The plant roots are helping to keep everything alive by providing habitat and food for bacteria, fungi and other soil organisms. Examples include plants with rhizobia, the nitrogen fixing bacteria inside the root nodules of legumes. The plant provides a capsule that is a low oxygen environment that these bacteria prefer, plus sugar for energy. The rhizobia bacteria provide nitrogen to the plant in return. Try to keep cover crops going as much as possible, because they are adding sugars and the roots are opening the soil up.

Humus
Humus is what is left over when all the microbes have a good go at eating everything out of the organic matter that they can eat simply. What is left is very stable organic matter (brown coal is humus worked over for a million years). A lot of material that is sold as compost is not the quality that we need. In a mature compost with high levels of humus the individual components (leaves, sticks etc) that made the compost should not be able to be identified. If you use unfinished compost you are activating all the soil organisms that compete with plant roots (as the microbes break the materials down). Compost is living and should be surface applied, and protected from drying out.

Soil biology
Bacteria, fungi, flagellates, ciliates, beneficial nematodes – there are an estimated 1 billion bacteria in a teaspoon of “healthy” soil; 1-40 miles of miles of fungi per teaspoon in the form of fine filaments; and hundreds of nematodes and arthropods. Where do microbes come from? Biodynamics uses one walnut sized piece of material turned in water and sprayed out over acreage. What is going on here? You have composted some cow manure; created a population of bacteria, fungi and nematodes that are beneficial; then you have multiplied the good organisms aerobically (anerobic are our badies) by stirring a vortex in the water.

Aerated compost tea One of the largest strawberry farms in South Australia has phytophthora in their ground water. They have knocked it out with compost teas that are aerated (plus they add nitrogen, molasses and lots of stirring energy) to create huge numbers of beneficial organisms and them put it through the irrigation system. You could get the same effect by 48 hours of bubbling with a fish tank aerator. Comment: There is a better way of aerating via an air pump that hyperoxygenates the water – this is what the strawberry farm uses, very energy intensive but saves time. Fungi – two classes that are really important. One of the major things about fungi and their mycelium generally, is they can massively increase the root zone that plant roots can get to, by up to ten times. Soil stabilisation in the Sahara with jujubes (Ziziphus jujube) has recognised the role of mycelium in these really harsh conditions. Mycorrhiza work with plants by entering or attaching to, the roots and swapping nutrients. This improves what and where your plants can get their food. Ectomycorrhiza – we see the fruiting bodies of these as toadstools and mushrooms. They do a trade off with plants. They latch on to plant roots. The plant gives the fungi sugars and fungi give the plant phosphate (often locked up) and other minerals. They also help give you more drought resilience, feeding water to the plants. Ectomycorrhizal fungi (ecto – outside/endo – inside) are the important ones for our trees – they are toadstools and mushrooms. But the other really important thing about organic matter is that the humus that is derived from woody matter and trees is the best humus for these ectomycorrhizal fungi so if you want to feed your woody trees and orchards with healthy compost and mulch, it should be wood based. Endomycorrhiza or Arbuscular mycorrhiza (AM) enter the plant roots to trade nutrients. They can produce a substance glomerulin, with glue-like properties which binds soil together and creates structure. They are associated with soft herbaceous plants and some of our trees. The humus that helps the endomicrorhiza in soft herbs and grasslands is best derived from their products – soft green materials. It is pretty obvious that fungi in the soil that has been feeding from the same products in the soil for a million years, is probably accustomed to that food. If you add the breakdown products from something different, it might not be good at all, and not quite as healthy. Make a distinction between what you use as mulch and the products you put in compost that goes to your trees versus your vegetables. Use straw in a vegetable garden and woody material in an orchard for ideal soil health. And it goes even further than that – research into Jarrah dieback (phytophthora) trialled humates derived from jarrah and other woody material. The Jarrah-based humates created the healthiest soil conditions and had the most effect on the dieback. Pyrophylous (fire-loving) fungi

Morels and boletes (Morchella and Boletus species) come after a fire, often as a result of the change in pH because of all the ash. They change the soil for the next species – we are more familiar with this phenomenon of establishment species in plants ecosystems.

What about mushroom compost? Mushrooms from mushroom compost are different to the type of things I am talking about. They are not associated with plant roots. Most mushroom composts have a component of peat and lime. Lime is probably not a problem for you, but I never add lime to compost, worm farms or anything, because I come from an area with incredibly alkaline soils. Wood ash has a pH 9-11 – strongly alkaline. You should always take the precaution of testing the pH of what you use. It is not uncommon for mushroom compost to be 8 or 9. Other than that you are looking at quite a good carbon product when compared with commercial compost, but it has had quite a lot of the protein (nitrogen) taken out of it by the mushrooms themselves. It is not as rich as compost that has not had something feeding on it. Bacterial slime – Leave a bucket of water that you have just done the washing in for a day, then run your finger around the edge. What you have there is bacterial slime. It is habitat that stops the bacteria from being washed away. It is their living area and part of what binds soil particles together. Try not brushing your teeth for a day – bacterial slime are quick at making their sticky glue stuff. This is what helps build soil structure.

Slime moulds (formerly fungi, but now protista) are predators of lots of other things. They looks like vomit, but are nothing nasty.

Other soil microbes
There are microbes in the soil that fix nitrogen like rhizobia associated with legumes. Archaea and eubacteria or cyanobacteria (sometimes called blue green algae) fix nitrogen and if you feed a lot of nitrogen to your soil you kill them and other things take over. Azotobacteria feed on sugar. There is a story of lime trees that had aphids and others that had no aphids. They were given the same fertiliser, water etc, but the ones with the aphids did a lot better. The sugar exuded by the aphids was going down on the soil, feeding the azotobacteria and they, in turn, were feeding the citrus roots. It is all about balance. The lateral spreading roots of a tree are the feeder roots – those that are in the healthy zone of the soil where fungi and bacteria also feed. People look at the drip line as to where the roots grow. The tree roots grow in air-filled, aerobic zones (avoiding compacted soil and anaerobic zones) and this is influenced by topography, adjacent structures etc. So the feeder roots are likely to follow an uneven pattern that does not follow the drip line. Tap roots are not feeder roots. They anchor the plant and get moisture. Feeder roots of vegetables in deep loams can go deeper than some trees.

Treating kikuyu infested clay
I apply a heavy dose of Rapid Raiser (high nitrogen, chicken manure based fertiliser), blood and bone, gypsum, coarse sand, covered with thick newspaper, then woody mulch and water. It is a completely dark situation. The kikuyu is not able to photosynthesise, it cannot produce sugars. Nitrogen will encourage growth, so it will draw on sugar reserves (eventually exhausting itself), but cannot produce sugars.

Soluble fertiliser in conventional agriculture
Conventional agriculture uses fertilisers that are soluble – the vast majority are salts. I look to use something that is 1-2percent nitrogen. If you use salt based fertilisers, you need to use a lot more nitrogen, because the salt will kill some of the bacteria, and fungi and so the soil is actually less productive from that sense. That is not a negative or a positive, just the reality. Using excessive soluble nitrogen (nitrates or ammonia or urea) is like going to McDonalds and having six hamburgers – it is a really big dose of food. Soluble nitrogen washes away and does not last long. You virtually need to feed at least every week with tiny amounts. We put our fertiliser out in big lots two or three times in the season. This gives them a big dose and then starves them for two or three months. Organic fertilisers break down slowly, feeding the soil, which feeds the plants.

What is protein?
Protein is nitrogen. So when you look at the microbes or bugs that are in the soil they are protein, so are mushrooms, fungi, single cells organisms etc. These life forms are also part of the fertiliser for the plant.

Potassium
These life forms also have a lot of potassium. The more organic matter and organisms you have, the longer potassium will stay in your soil. If you are using a fertiliser that has a higher level of nitrogen than potassium, you are pushing that plant into a vegetative growth phase more than flowering phase. Potassium is very important when it comes to flowers and fruit. Seaweed has potassium.

Phosphorous
When it comes to phosphorous, 90- 95% gets bound up almost immediately to calcium, iron and other irons in the soil and becomes insoluble phosphates. Superphosphate has sulphuric acid added to it to make it more soluble. Acidification is a long term consequence. Fungi can release phosphorous and feed it to your plants, so once you start looking at organic systems, you may not need to look at phosphorous as being such an important input as you do under conventional systems. Rock dusts (granite, basalt, other volcanic rocks), are the freshest out of the earth’s crust, but those minerals are not very soluble. It must be crushed into very fine powder and added to a compost. Alroc do quite good stuff with humates and rock dust (best form of phosphorous). A conventional farmer from western Victoria looked at use energy on his property – tractors, mechanical devices, diesel use etc, but 43% of energy use was fertiliser. That is why they have regulated calcium nitrate (saltpeter). It has enough energy to make bombs and that energy has come from gas. They take nitrogen from the atmosphere and make ammonia and urea which uses a huge amount of energy and much of this energy is wasted.

Manures
Fresh manures are very high in nitrogen, a lot of which is soluble nitrogen. That is why you can smell manure – with anything stinky you are smelling the loss of nitrogen. I do not use manures straight – for safety reasons, but also you are wasting the nitrogen. Use it in a compost. The nitrogen in compost will last longer in the soil than the nitrogen in the manure, because the nitrogen is in bacteria and fungi that do not get leeched or vaporised.

Hydroponics
Hydroponics suggests we can grow plants with 16-17 minerals – not a healthy thing for us. Well over 60 are necessary/desirable. Selenium is an example. Only minute quantities are required, but it is a common deficiency in animals and humans.

Why do we graft? To get fruit earlier, to get consistency or to get a particular variety. When you add a graft you are putting on the variety you want, but you are giving that juvenile plant aged material from another plant so it becomes a mature plant and fruits earlier than a non-grafted plant. For successful grafting we need to have as much carbohydrate in the scion as possible for that type of plant. That does not relate to size. It relates to time of year or how you have prepared it. Dormancy, before a plant throws buds (flowers or vegetative), is the time that it has the most carbohydrate stored in the stem. Take cuttings and scion material in a dormant phase for the most chance of success in grafting because sugar that comes from the scion that forms part of the callous tissue. With evergreens, there are ways of preparing the scion material. Cincture the plant or cut the leaves off something that you are going to graft – 2-4 weeks before you graft, but leave the petioles. This helps concentrate the sugars. The rootstock needs to be in an active phase of growth in evergreens to get the most rapid healing. After care has a lot to do with your success. Protect grafts from sunlight, wind and ensure no shocks from changes of environment or temperature. Rub off anything that is growing from the rootstock below the graft. (more detailed information can be found in the CSIRO book Practical Hints for Budding and Grafting Fruit and Nut Trees.)

Question regarding fruiting of jujubes in Queensland. They have every chance of success (one fruits in Sunnybank). The biggest issue is the rootstock used to graft plants (Ziziphus mauritania) is a declared noxious weed.

Recommended reading on soil includes: Gardening Down Under by Kevin Handreck, Landlinks Press (2001) Designing and Maintaining Your Edible Landscape Naturally by Robert Kourick, Metamorphic Press (1986); Permanent Publications (2004) Composting: The Ultimate Organic Guide to Recycling Your Garden, Tim Marshall, Harper Collins/ABC Books (2008) Teaming with Microbes: A Gardener’s Guide to the Soil Food Web, Jeff Lowenfels and Wayne Lewis, Timber Press (2010) Teaming with Nutrients: The Organic Gardener’s Guide to Optimizing Plant Nutrition. Jeff Lowenfels and Wayne Lewis, Timber Press (2013).

Also any works by Dr. Elaine Ingham of the Soil Food Web.

Note:  With thanks to Annette McFarlane for writing up Harry’s talk.

Our mate “Harry” passed away 7th April 2019.

Below is a poem written by Kate Hubmayer from the Glandore Community Garden

19th May 1958 – 7th April 2019

As skinny as a worm With a smile as bright as Spring You were as subtle as a Sunflower

And had the energy of a Radish.

You could talk for as long as a New Guinea Bean And sing like a bird You were as funny as a Brussels Sprout

And as generous as an Olive Tree.

You were as feisty as a Chilli And as soft as a Guava You nurtured our soil with compost and worm juice

And enriched our lives with your knowledge and friendship.

Your passion for gardening has wound around us like tendrils
And we will keep on gardening, nourished by the memories.

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As a general rule most fruiting plant species are graft compatible within their specific group so that apple on apple, pear on pear, plum on plum, peach on peach (includes nectarine), apricot on apricot, citrus on citrus etc. will generally graft successfully.  Plants (rootstocks) grown from seed are often virus free and so have a better performance rate than scion to scion grafts but they too may have problems such as being susceptible to a given pest or disease.  It was not until scientists could produce virus-free plants and use an electron microscope to identify viruses (Plant Research Institute Burnley, Victoria) that it was discovered most propagating material in Australia pre-1960’s was full of virus and some of these viruses had a tremendous influence on incompatibility problems when grafting.  Using virus free material (buds) improved growth and cropping almost tenfold and grafting success was also improved enormously.

Peach and nectarines (actually a peach variation) have been used as a rootstock for most of the Prunus species including peach, nectarine, plum, apricot, prunes (a plum variation) and almond.  There are variations between varieties and within species of the success of bud or graft ‘take’ (success).  For instance, the union may have a dwarfing effect, there may be ‘overgrowth’ between the scion and stock (one or the other grows faster creating a different sized trunk or stem at the union).  Some graft unions can perform well for a short period then die, others are mildly incompatible and can last years before decline occurs.  Some unions grow a large callus and eventually ‘choke’ the graft area with excess callous growth.  Others are quite successful.

Using seedling plants you, of course, are using a different cultivar/variety every plant you choose because although seedlings can come fairly ‘true to type’ and look the same and may even produce almost identical looking fruits, there are genetic variations in every one just like there are variations between brothers and sisters in human family populations.  If the original seed source tree is very isolated from other fruit trees of the same family it may give very good seedling without too much variation and they might be OK as rootstock material but the only way to find this out is to trial the rootstock material.  As trees age they can pick up viruses (i.e., transferred by sucking insects) that can affect the purity of the rootstock material and diseases such as bacterial gummosis and silver leaf can get into the plant system.  These problems can affect the way the plant will accept a bud or graft and can lead to incompatibility (will not form a graft) between bud or scion and the rootstock.  If you have a good rootstock it would be best to propagate the material from cuttings to get identical plants.  Peach and nectarine rootstocks are very subject to waterlogging and do not tolerate wet soils for long periods.  Flooding and waterlogging often occur on and within some of the typical heavy clay to clay loam soils common in Australia.

On the positive side of this exercise you may be able to grow a multi fruiting tree with peach, nectarine, plum, sloe?, prune, almond (may need an inter-graft of a compatible species), apricot all on the one tree or you can have one tree with many different varieties on it if your rootstock is OK!!  Personally, if you want to choose a rootstock for Prunus species, I would buy a grafted plant, cut it to below the graft area and then by stooling the tree, grow your own rootstock.  Alternatively, obtain material (i.e., hardwood cuttings) from a roadside cherry plum as they usually perform better than peach or nectarine re compatibility and disease/waterlogging/climate/pest and disease resistance.

For your information, I have last spring (2010) cut down a very old cherry plum tree that had five limbs over 200mm wide, one metre about ground level, and into these I placed over thirty bark grafts of about 8 different cultivars of plum, peach and prune gathered from local home garden trees.  The inserted graft scions were sealed with grafting paint on the upright end and the scions were then enclosed in a moisturized plastic sleeve.  The success rate was great, only three grafts failed.

Sheryl:  One of our members Ray Johnson from Gin Gin does a lot of grafting and contacted Allen Gilbert and asked about grafting.  This article (above) was his reply.  Allen has written numerous books on various aspects of horticulture.

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Dragon Fruit can last for up to 2-3 weeks in a plastic bag if kept in the refrigerator. You can also freeze dragon fruit but the texture will be altered and it will best be used in a sauce or sorbet.

Simple Dragon Fruit Ice Cream    ref: Raymond Patterson – Pitaya yahoogroup 2 cups dragon fruit 2 cups half and half (half light cream and half milk) 1 cup sugar

I’ve experimented with other sweeteners to cut down sugar level, so far the only working alternative I’ve found is agave nectar, as the cactus sweetener seems compatible with the dragon fruit.

Pashionate Dragon Ice Cream   ref:  llnickers – Pitaya yahoogroup Warm 1 cup milk in a small saucepan.Whisk 2 eggs with ½ cup sugar in a separate bowl. Slowly add the warm milk to egg mixture continuing to whisk. Pour mixture back into the pan and heat slowly until thickened, stirring constantly. DO NOT BOIL. Let cool to room temperature Add 2 cups of cream or half cream/half milk plus 2tsp vanilla and chill overnight. Put in a 1 quart ice cream maker and follow manufacturer’s instructions.

Add 1- ½ cups peeled dragon fruit cut into ½” cubes dragon fruit chunks and ½ cup passionfruit (strain out some of the seeds) just before the end of the freezing process – or ¼ cup lemon juice can be substituted for passion fruit.  Makes about 1 litre.  Yum!

Dragon Fruit Ice Cream using Coconut Milk Cut your dragon fruit in half, use a spoon and remove all the fruit and process in a food processor.

Combine 1 can full fat coconut milk (475ml), 3 egg yolks, 1 tsp vanilla and a pinch of sea salt in a sauce pan over medium heat. Bring to a mild boil constantly whisking. Remove from heat and let cool. Add your dragon fruit to your cooled coconut milk mixture. Once mixed, place in your refrigerator to cool, for at least 2 hours but you can leave it overnight. Remove from the fridge and immediately use in your ice cream maker after you mix it slightly to ensure nothing settled. This ice cream will not turn into a brick like most coconut milk ice cream. Enjoy once it is done. Live on the edge a little and serve in the shell of the fruit. Enjoy.  Ref:  http://civilizedcavemancooking.com/recipes/desserts/dragon-fruit-ice-cre…

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A mineral element is considered as essential, when plants cannot complete reproductive stage of life cycle due to its deficiency. Deficiency must be corrected only by supplying the element in question and when the element is directly involved in the metabolism of the plant (Arnon, 1954). Based on these criteria, sixteen elements so far were identified as essential. These are: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, iron, manganese, zinc, copper, boron, molybdenum and chlorine. Most of the carbon as carbon dioxide enters the plant from the air; hydrogen and oxygen are taken up as water. The rest of the elements are taken up from the soil solution as mineral nutrients. Among these nutrients N, P, K, Ca, Mg, and S are considered major or macro-nutrients, because they are required in large quantities that range between 1 to 150 g per kg of plant dry matter. Fe, Zn, Mn, Cu, B, Mo and Cl are minor or micro-nutrients that are required at rates of 0.1 to 100 mg per kg of plant dry matter (Marschner, 1997a). Chloride is essential in micro quantities but can accumulate in the plant in large quantities when present in high concentrations in the soil solution, (Xu et al., 2000).

All the essential nutrients are required by plants in balanced proportions. Deviation from this may result in nutritional disorders. Early detecting of nutritional deficiency stress is important. Stress might extend to the entire plant with loss of yield if relief of stress is not employed. Continuous shortage of a nutrient or nutrients might cause plant death. When two or more elements are deficient simultaneously, the composite picture of symptoms may resemble no single known deficiency. Mineral deficiency symptoms are sometimes confused with other complex field events such as damage caused by insect-pest, disease, salt stress, water stress, pollution, light and temperature injury (Bennett,1993) and herbicide damage. Toxicity of Mo or Se is similar to P deficiency (Bennett, 1993), Fe deficiency in Mango is similar to Chloride toxicity (Xu et al., 2000). Therefore, it is necessary to critically observe and define these deficiency symptoms. The deficiency symptoms might be distinguished based on the plant part that shows deficiency symptoms, presence or absence of dead spots and entire leaf or interveinal chlorosis. A description of initial appearance of deficiency symptoms on leaves is given in Fig.1 and the associated text below. Generally, nutrient deficiency in the plant occurs when a nutrient is insufficient in the growth medium and/ or cannot be absorbed and assimilated by the plants due to unfavourable environmental conditions. Nutrient disorders limit crop production in all types of soil around the world. Table 1 shows soil conditions associated with nutrient deficiencies of various nutrient elements.

Visual symptoms of nutrient deficiency – Photos   http://www.hbci.com/~wenonah/min-def/list.htm

Boron (B) 
Boron deficiency causes yellowing or chlorosis of youngest leaves and stems (Yu et al., 1998) which starts from the base to the tip. Rosetting of terminal shoots of potato (Roberts and Rhee, 1990). Leaf tip burn, elongate and become whitish brown in rice (Yu et al., 1998). Death of terminal bud occurs in extreme cases. Boron deficiency causes brown heart in radish (Shelp et al., 1987) and crown choking in coconut (Baranwal et al., 1989).

Calcium (Ca) 
Calcium stress in plants results in chlorosis of young leaves along the veins of birdsfoot trefoil (Russelle and McGraw, 1986) and blueberry (Tamada, 1989), if deficiency persist longer, bleaching of upper half leaf followed by leaf tip curling do occur in black pepper (Nybe and Nair, 1987) and sugarcane (Nautiyal et al., 2000). The growing bud leaf becomes chlorotic white with base remaining green, the distortion of the tips of shoots i.e. dieback was observed by Edwards and Hortan, (1997) in peach seedlings. Similarly, Spehar and Galway, (1997) found brown spots on leaves, reduced expansion and premature leaf senescence under Ca stress in soybean crop. Stress during fruiting in tomato increases susceptibility to blossom end rot (Adams and El-Gizawy, 1988; Sonneveld and Voogt, 1991 and Ho et al., 1999). Calcium stress is also responsible for other disorders such as bitter pit in apple (Ford, 1979; Monge et al., 1995 and Silva and Rodriguez, 1996); leaf tip burn in cabbage (Miao et al., 1997) and lettuce; black heart of celery; cavity spot of carrots (Scaife and Clarkson 1978); vitrescence in melons (Jean-Baptist et al., 1999).

Chlorine (Cl) 
The symptoms of chlorine deficiency develop first on the older leaves. Discrete patches of pale green chlorotic tissue appear between the main vein near the tip of the leaf, downward cupping of some of the older leaves of Kiwifruit was observed by Smith et al., (1987). The leaflets of youngest leaves shrivel completely, older leaflets develop a brown necrosis which start near the tip and extend backwards particularly at the margins of red clover (Whitehead, 1985).

Copper (Cu)  
In copper deficiency, visible foliar symptoms appear on young leaves as chlorosis changing to necrosis (Conover et al., 1991; Del, 1994); rolling, wilting and twisting of leaves in wheat (Owuoche, 1995). The later affected leaves appear papery and twisted in rice (Nautiyal et al., 1999 ).

Iron (Fe) 
The principal veins remain conspicuously green and surrounding portion of the younger leaves turn yellow tending towards whiteness in chickpea (Mehrotra and Gupta, 1990 and Saxena et al., 1990); groundnut (Reddy et al., 1993); radish, cauliflower, cabbage and sorghum (Preeti et al., 1994); lentil (Zaiter & Ghalayini, 1994) and soybean (Fonts and Cox, 1998). Under severe deficiency, most part of the leaf becomes white (Russelle and McGraw, 1986 ).

Magnesium (Mg)
Magnesium deficiency causes yellowing, but differs from that of nitrogen. The yellowing takes place in between veins of older leaves (Makkanen, 1995) of Picea abies and veins remain green, this is followed by necrosis of tissues in birdsfoot trefoil (Russelle and McGraw, 1986), melons (Simon et al., 1986). black pepper (Nybe and Nair, 1987) and blueberry (Tamada, 1989). Mg deficiency my be induced in tomatoes by high levels of ammonium in the nutrient solution (Kafkafi et al., 1971).

Manganese (Mn)
The principal veins as well as smaller veins are green, the interveinal portion become chlorotic in Ailanthus triphysa (Anoop et al., 1998) followed by necrosis and browning of interveinal tissue in melons (Simon et al., 1986). The affected young leaves remain small and abscise before older leaves in birdsfoot trefoil (Russelle and McGraw, 1986).

Molybdenum (Mo)
The common symptoms of Mo deficiency in plants include a general yellowing, marginal and interveinal chlorosis, marginal necrosis, rolling, scorching and downward curling of margins in poinsettia cultivars (Cox and Bartley, 1987; Cox, 1992) and in various field, horticulture and forage crops (Gupta and Gupta, 1997). The deficiency of molybdenum in cauliflower causes the disorder described as ‘Whiptail’ ( Duval et al., 1991).

Nickel (Ni)
Plant growth is reduced and older leaves turn chlorotic giving plants a nitrogen deficient phenotype, when grown on urea-based nutrient solutions not supplemented with Ni in tomato and soybean (Shimada and Ando, 1980; Krogmeier et al., 1991). Similar results were obtained in oilseed-rape, zucchini and soybean by Gerendás and Sattelmacher (1997).

Nitrogen (N)
The characteristic deficiency symptom of nitrogen is the appearance of uniform yellowing of leaves including the veins, this being more pronounced on older leaves as expressed in rabbit-eye and blueberries (Tamada, 1989); Fescue (Razmjoo, 1997); Ailanthus triphysa (Anoop et al., 1998); chili (Balakrishnan 1999) and sugarcane (Nautiyal et al., 2000). The leaves become stiff and erect. In dicotyledonous crops the leaves detach easily under extreme deficiency condition. Cereal crops show characteristics ‘V’ shaped yellowing at the tip of lower leaves. O’Sullivan et al.,(1993) observed relatively small and pale green leaves with dull appearance in sweet potato. If such condition of nitrogen stress do persist, the result is a decreased foliage growth and shoot growth. See for example: black pepper (Nybe and Nair, 1986); douglas-fir (Friend et al.,1990) and sapota (Nachegowda et al.,1992).

Phosphorus (P)
In phosphorus deficiency, leaves remain small, erect, unusually dark green with greenish red in sweet potato (O’Sullivan et al., 1993), bluish green in chili (Balakrishnan 1999), brown in birdsfoot trefoil (Russelle and McGraw, 1986) or purplish tinge in sugar maple (Bernier and Brazeau, 1988); blueberry (Tamada,1989) and sugarcane (Nautiyal et al., 2000). The under side develops bronzy appearance. The root growth is also restricted under phosphorus stress in black pepper (Nybe and Nair, 1986). Anthocyanin pigment increases in leaves of barley (Hamy,1983) and Arabidopsis thaliana (Trull et al., 1997) under phosphorus stress,

Potassium (K)
Under potassium stress condition, yellowing of leaves starts from the tips or margins of leaves extending towards the center of leaf base. The yellowing is interveinal and irregular in the leaves of tomato (Besford, 1978) and blueberry (Tamada, 1989). These yellow parts become necrotic (dead spots) with leaf curling in tobacco (Arnold et al., 1986); sugar maple (Bernier and Brazeau, 1988); sapota (Nachegowda et al.,1992) and sugarcane (Nautiyal et al., 2000). There is a sharp difference between green, yellow and necrotic parts.

Sulfur (S)
Sulfur deficiency cause leaves to become yellowish in black pepper (Nybe and Nair, 1987); potato (Gupta and Sanderson, 1993) and Brassica oleracea (Stuiver et al., 1997) and it appears similar to nitrogen deficiency, but the symptoms are first visible on younger leaves (Russelle and McGraw, 1986). The affected leaves are narrow and the veins are paler and chlorotic than interveinal portion, especially towards the base with marginal necrosis in sugarcane (Nautiyal et al., 2000).

Zinc (Zn)
The leaves become narrow and small in chili (Balakrishnan, 1999), the lamina becomes chlorotic in sweet potato (O’Sullivan et al., 1993), sour orange seedlings (Swietlik, 1995) and chickpea (Khan et al., 1998), while veins remain green. Subsequently, dead spots develop all over the leaf including veins, tips and margins under sever deficiency, shoot growth is reduced (O’Sullivan et al., 1993; Swietlik, 1995 and Yu and Rengel, 1999). Khaira disease in rice results due to zinc deficiency (Gautam and Sharma, 1982; Sharma et al., 1988 and Sahi et al., 1992). Shoot elongation is reduced and a tuft or rosette of distinctly narrow leaves is produced at the shoot terminal in apple and pear. The symptoms are termed ‘little leaf’ or ‘rosette’ (Hanson, 1993).

Sheryl:  Annette McFarlane’s new book on Organic Fruit Growing has a list of all the nutritional elements and what they do so do have a look.

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I want to talk to you tonight about a way of controlling insect pests without using insecticide. The technique is called ‘mating disruption’. I’m also going to talk to you about sex because that is what we are manipulating with the technique. It makes use of pheromones, which are defined as chemicals emitted by an individual to send messages to others of the same species. The work is made up from two Greek words – Phero meaning “to carry” and Hormone meaning “to excite or stimulate”. There are a number of different kinds of pheromones but tonight I’ll be talking about sex pheromones, which are a bit like perfumes and are used for attracting mates. Each species has its own unique pheromone and, in the case of moths, are almost always produced by the female.

I work exclusively with moths, although many other insect orders also have pheromones. In moths pheromone is produced and released from a gland that sits at the tip of the abdomen of the female. When the warehouse moth (Ephestia cautella) releases pheromone, or ‘calls’, she curls her abdomen up so that the gland sits above the wing tips. Some species curl the abdomen down and other species don’t do anything obvious at all.  The pheromone is carried off downwind and is detected by the male, who then flies upwind towards her. Pheromones are pretty powerful things  – males only needs a few molecules to excite them, so a little bit goes a long way.

How can we use sex pheromones? One application is as baits in traps, where a small quantity, similar to the amount that a single female would carry, is evaporated from a substrate such as a piece of rubber tubing. In other words the bait is a synthetic version of the female.  Males pick up the scent and come to the trap thinking that they’ll find a female. But all they do is come to a sticky end! Pheromone traps can be used for monitoring and surveillance. For example the Australian Quarantine and Inspection Service (AQIS) uses them around ports to detect the Asian gypsy moth, which is harmful species that can come in by accident. The traps can be used by growers to determine what pest populations are doing. If they monitor their traps on a regular basis they can see whether or not the population is increasing and so decide when to put on control measures or they could use them to indicate whether they have the pest at all.

Mass trapping is a technique that was once thought to have potential as a means of pest control. It was assumed that by trapping and removing enough males, populations would decline and control would follow. However it very rarely works for moths because most males can mate more than once. Even if you trap 80 or 90% of available males, and that is almost impossible to achieve, those that are left behind can still mate with enough females to cause significant damage.

‘Attract and kill’ is a bit like mass trapping except that you use a pheromone in conjunction with an insecticide. The two are put out together as a paste so that when the male is attracted by the pheromone he gets a fatal dose of insecticide. This method is relatively new and is still being evaluated.

Pathogen distribution via moths attracted by pheromone to inoculation chambers is another relatively new technique that has some potential for insect pest control. After the male enters the chamber he gets infected with a pathogen, such as a fungus, which he then takes back out and spreads to others within the population. The pathogen is fatal and causes the insects to die within a few days of becoming infected.

I’ve already mentioned mating disruption briefly and now I’d like to tell you about how we developed the technique for control of a clearwing borer moth in persimmons. It involves releasing large quantities of synthetic pheromone in the orchard. This confuses the males, who simply don’t know which way to go to find the females. If he can’t find a female no mating takes place and we get control.

George Is there only the one signal they use to find a female?

Richard In most cases with moths it is. Some insects use sound and/or sight too: butterflies for example use sight as well as pheromones. But for the moth species we work with it’s almost exclusively odour, at least until the males get very close to the female, when visual cues are sometimes used.

To be honest, we’re not 100% sure how mating disruption technique works – there are a number of possibilities but a likely scenario is that releasing all that pheromone creates a lot of false trails that the males follow without finding a female. It is also possible that with so much synthetic pheromone about the male’s sensory systems become overloaded and are no longer able to detect the small quantities of pheromone released by the female. It’s a bit like us when we come across a bad smell. If we are exposed to it for long enough, our sensory system becomes adapted and we get to the stage where we no longer notice it.

The insect that is creating a real problem in the Persimmon industry is a clearwing moth. Until a year or so ago it was known as Carmenta chrysophanes but then the taxonomists got hold of and changed its name to Ichneumonoptera chrysophanes. It’s much easier to say Carmenta, but tonight I’ll just call it a clear wing moth! Unlike most moths, this one responds to its pheromone during the day, which is a bit of a luxury for us because we like to see how our moths are behaving and with most species that means going out with night vision goggles or infrared light just to see what’s going on.

George Is it a native?

Richard Yes but there are related species in many other parts of the world.

George I don’t think I’ve ever seen one.

Richard No, but you might have seen the damage that they do. In terms of their appearance there’s quite a bit of difference between the male and female, but for most of the moths I work with there isn’t any obvious difference between male and female.

Sheryl What size are they?

Richard About 1cm long. These moths don’t touch the fruit – they ringbark. They’re called borers because the larvae get into the timber itself and cause damage around new shoots as well as old ones. I’ve seen whole limbs that have dropped off trees and in one case in Redland Bay an entire tree had fallen over. I’ve been told by a couple of growers that this insect is limiting expansion of the industry because they haven’t got an effective control measure, other than netting the orchard. The industry had heard of our success with some other fruit tree pests and approached us to see if there was anything we could do for them. There are no chemicals registered for use with this pest and as you can imagine, once the eggs have been laid and the larvae burrow into the tree, they’re almost out of reach of insecticides. New damage is often seen at the base of young shoots (Fig. 1), where small piles of fresh frass are left as larvae burrow in and feed on the layers beneath the bark. Older, larger wounds (Fig. 2), sometimes at the juncture of branches with the main trunk, may also be evident.       

Fig. 1. New damage at base of shoot                                     Fig 2. Old damage

The moth has a number of alternative hosts, including several Eucalyptus, Wisteria and Ficus species as well as Alphitonia excelsa. It has also been recovered from galls on Exocarpos cupressiformis. Its distribution is mostly confined to the east coast of Australia, although one specimen has been recorded from the ACT. When this project started I was approached by some growers in South Australia who also have a borer problem. They have provided some of the funding for this project, but unfortunately it appears that the pest they have down there is not the same one that we have in NSW and Qld. I’ve not been able to get specimens of adults from SA so I still don’t know just what is causing their problem.

Conventionally pheromones are identified by extracting the contents of the pheromone gland and feeding them through a gas chromatograph (GC). Then the components are tested in field trials to confirm that they are attractive to the insect. Now as you’ll probably be aware, the persimmon industry doesn’t have a lot of money for research and so when they came to us to see if we could help we indicated that because of the limited budget we would take a few shortcuts in trying to identify the pheromone. Then we would see how we could use it for control purposes. Our initial research was done down at Redland Bay and subsequent trials were done on Ben Jeffers’ place up near Nambour.

Fortunately the pheromone for many of this insect’s close relatives had already been identified, which made our task much easier. It turned out that, almost without exception, their pheromones were confined to 4 or 5 different types of chemicals, so we knew right from the start we had a good chance of making an identification simply by putting out combinations of these components and seeing what we could catch. With each successive trapping trial we refined our blends until we had something that we were confident was an effective attractant. We tried a number of alcohols and acetates on their own and in combination and eventually found that a 90:10 ratio of the acetate to the alcohol caught more moths than any other combination. Then our chemist offered to run a sample of pheromone extracted from the gland through the GC at no charge, just to confirm that the compounds and their ratios that I’d identified in my trapping trials were similar to those in the gland. Sure enough, I had the right components and they were in the right ratio.

The next stage was to see whether we could control the insects using the pheromone as a mating disruptant. This is a typical pheromone dispenser. It’s a polyethylene tube with a wire on one side to tie around the tree and the pheromone column on the other side. This particular pheromone doesn’t have any smell that my nose can detect, although some do. One dispenser contains pheromone equivalent to about 100,000 females! We recommend putting out a 1000 per hectare, so you’re talking about the equivalent of 100,000,000 females. Now perhaps you can see why the male could get a little confused!

Sheryl How much are they?

Richard It depends on the chemicals that go into them. This is now a commercial product and I think they are selling for around $300-$400 per hectare. Bio Control is the agent for the dispensers in Australia.

We set up the trial at Nambour in an orchard with two blocks about 50 m apart. We put dispensers in one (the ‘treated’ block) but not the other (the ‘untreated’ block) and in both we put in pheromone traps. If mating disruption is going to work then males should not be able to find pheromone traps where dispensers are present. And we assume that if they can’t find a pheromone trap then they’re not going to find a female either, although there are some exceptions.  What we hoped to see in the treated block was very few or preferably no catches in the traps but plenty in the untreated block. Likewise in terms of damage, we hoped to see much less damage in the treated block than in the untreated block. The trial ran for 9 months – the adults are around for a long period in this part of the world – and we caught large numbers of moths where there were no dispensers but absolutely nothing in the traps where there were.

Dispensers were put out in September and as some damage was already evident when we started the trials, some mated females may still have been present, meaning that further damage could arise even once the dispensers had been installed. What we hoped to do was limit damage to well below that sustained in the untreated block. We conducted two damage surveys – one in December and the final one in the following June. Seventy six trees were inspected in both blocks in the first survey, of which 2.7% were damaged in the treated compared with almost 19% in the untreated block. Damage levels in the June survey were quite high in the treated block – 20.5% , but much higher – 57%, in the untreated.

A feature of this sort of control programme is that it can take a couple of years to get damage down to an acceptable level. We and the growers were quite happy with the result, providing that in subsequent years damage could be reduced even further. We’re now into the second year and have 19 growers using the technique. Time will tell whether we can push damage levels down any further, but the results are quite encouraging. One adjustment we will recommend is that instead of having only one set of dispensers go out into the orchard in the hope that it will last the entire season, we will recommend that a second set go in around New Year.

Data we collected when we first began these trials indicated that after nine months pheromone release rates had dropped to less than 4 mg/hectate/hour. When you think that for at least one species we worked with we had to keep the release rate above 6 mgs per hectare/hour for mating disruption to be effective, it may be prudent to add a second set of dispensers and keep the release rate a little higher.

There’s a closely related pest that gets into currants in Tasmania and New Zealand and we have the pheromone for that. There’s another one that’s a problem in peaches in America. Again it’s the tree that suffers – not the fruit.

Mating disruption is not a system you can use in your backyard – it’s only suitable for reasonably sized orchards.

George   I’ve tried wicks but they’re only suitable for fruit fly.

Richard The wicks contain interesting compounds. They’re called psuedo or para-pheromones because they are not actually what the males produce themselves, although the true pheromones may be derived from them after they have been ingested. Fruitfly para-pheromones are very powerful attractants.

Jim Were you using the same materials in your attraction technique in the SA examples or were you trying something different there. 

Richard The same compounds – we know it’s a different insect but I’ve not been able to get the adults I need for identification purposes.

Sheryl So what can we do for the backyard – netting? Can you put a piece of wire in and dig them out?

Richard Netting has been tried by some growers and apparently does work. However digging larvae out isn’t likely to be effective. They get pretty well into the tree and you would probably do more damage trying to dig them out. In any case I don’t think you could kill enough for it to be effective. You’re not going to get them all.

George When you dig around, how many do you see?

Richard We tend to see only singles or 2 or 3 so it’s likely that the female lays only a few eggs in any one spot. Little is known of the insect’s life cycle, but the relatively few generations a season (possibly only two) may reflect the food that the larvae are getting. You can imagine that the nutrient value of bark and wood is not as great as fruit might be, so it takes longer for the larvae to mature. The climate, at least in Queensland, means that it is warm enough to enable development to continue for much of the year, which may be why we have such an extended period during which adults are about.

Richard The larvae spend their entire life cycle in the tree. They pupate in the tree as well so there is no immature stage of the cycle that is not on the tree.

Sheryl What’s your next project?

Richard Diamondback Moth on cabbages. I mentioned at the start of the talk that pheromone could be used to bring males in to an inoculation chamber, where they become infected with a fungus that they take out and spread amongst their own population. We ran some trials about 18 months ago to test the concept and they worked quite well.  Now we want to scale up.  I’ve spent most of today writing a grant application for some funds to finance the project.

George These techniques aren’t going to work on the Fruit Piercing Moths

Richard No. However I believe Harry Faye at DPI Mareeba is about to patent an attractant for the Fruit Piercing Moth. It’s not a pheromone – it’s a food attractant. With this moth the difficulty is that they fly in to the orchard in response to the smell of the fruit, feed on it and then leave. In other words they are not resident within the orchard for very long, which doesn’t give you much time to do anything about them.  I’m generally a bit doubtful about the likelihood of food attractants succeeding, simply because there’s so much competition in the form of natural food. For this reason artificial baits have got to be much more attractive to the insect than its natural food.

Sheryl – I remember Peter Young saying that they really like Carambolas so if you put out a bait with these perhaps you can distract them.  Is there any other research happening with fruit?

Richard Geoff Waite DPI at Nambour has been working on a pheromone for Fruit Spotting Bug. When the project started six years ago the claim was made that there were six components to the pheromone, five of which had already been identified, but as far as I’m aware there is still no effective pheromone for this pest.