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1. Highest possible profitability 2. Earliest fruit production and $ returns 3. Highest possible yield per hectare 4. Consistent reliable yield every year 5. Long lived orchard 20-30 years 6. High quality fruit of desired size 7 Easy management – pruning, thinning, spraying, harvesting etc. 8. Able to physically protect crop as required    frost, hail, birds etc.

9. Able to grow desired crop on marginal soil types

The above can be achieved if we: a) Select the correct variety to suit the climate and market b) Use proper cultural management techniques c) Select the correct rootstock – not necessarily dwarfing d) Limit tree size to a maximum height of 4-6m

e) Use correct canopy management techniques

Limiting Tree Size and Maintaining Regular Cropping

Smaller trees will obviously produce less fruit per tree than larger trees. It is therefore necessary to plant smaller trees closer together to achieve the highest yield possible per hectare. There is well documented research that high density, deciduous and citrus orchards with more easily managed small trees will make better use of sunlight and as a result will consistently produce higher yields collectively per unit area than wide spaced orchards in the long term.

The difficulty in the past has been to manipulate and control naturally tall growing subtropical fruit trees by timely pruning and managing the canopy to discourage strong summer growth while still producing enough growth to produce heavy crops. These trees must produce new growth each year to develop and mature the existing crop and at the same time produce extra food reserves in stems and branches for next year’s crop.

Recent research in the past 5-10 years has resulted in a better understanding of tree growth cycles or phonological cycles to enable timely tree manipulation to control tree growth and size and to know what to do when. Subtropical fruit growers that do not have an established culture of timely pruning may have difficulty in coming to terms with canopy management. Mangoes and Lychee that have a simple, clear 12 month flowering, fruiting, harvest, growth and dormancy cycle are much easier to manipulate than Avocados. Avocados can have a simple cycle when fruit mature before flowering in warm subtropical areas. However the late maturing Hass variety when grown in cool to cold areas mature fruit so late that often growing cycles overlap and flowers and/or young new season fruit are competing for 2-3 months before the previous season’s fruit is harvested. The result is often biennial bearing with an acceptable crop only being harvested every second year. New varieties should be planted in cool areas that not only mature
fruit later but flower later so seasons don’t overlap to enable easier canopy management procedures and regular annual cropping.

Controlling Tree Size using Canopy Management Techniques

1. Promoting Heavy Early Bearing

The best way to slow tree growth and contain tree size is to promote heavy early bearing. Once trees are well-established 4-6 months from planting, tree complexity must be rapidly increased to develop as quickly as possible as many horizontal fruiting laterals that have fruiting potential. By carrying out ‘controlled leader pruning’, the young tree is still able to grow upright while still producing laterals for fruiting. Good levels of well balanced nutrients must be applied to promote, strong growth and heavy fruiting.

2. Promote and Develop Multi Leader Growth Habit

This is important for when trees reach maximum height when we need to implement major limb removal to reduce tree complexity and keep the orchard ‘young’ to ensure new growth is produced each year and fruit size is maintained. The development of multi leaders happens with little effort as all trees will do this as part of their natural growth habit. The number of leaders that naturally develop is dependant on tree spacing that determines light availability.

3. Maintain Desired Tree Shape

This should start as early as possible after tree establishment and strong growth commences. Most unpruned stand alone trees have a natural growth habit. Some grow upright and some spread out. Almost all subtropical fruit cultivars will grow more or less in a pyramid shape until fruiting occurs. Heavy fruiting has the effect of weighing down branches and shading the branches below. During this period summer growth develops into the open spaces where light is now plentiful to once again to be weighed down next year. Lower branches that become continually shaded by higher branches soon die out due to lack of sunlight. The long term result is that of an inverted pyramid shape wider at the top and narrow at the bottom with fruit being produced higher and higher up the tree as lower branches die out

By selectively pruning back vigorous terminal shoots higher up in the tree at the correct time of year ensures less fruit is produced higher up, lower branches are maintained through good light exposure and produce more fruit down low. A ‘narrow pyramid’ shape or ‘tent shape’ should be selected to suit the growth habit of each specific fruit cultivar and pruned at the correct time of year. The correct time of the year to selectively head back or tip prune strong high growth back to tip prune strong high growth back to laterals is 3-4 months prior to cold weather or ‘dormancy’ to limit regrowth time but still allow mature enough growth to develop and properly flower and set a good crop. Heavy late pruning may result ‘m growth that is too immature to set fruit in spite of flowering due to insufficient food reserves. Heavy or too frequent early pruning of the spring growth flush will encourage excessive stronger summer growth that will require more regular selective hand pruning during summer.

4. How and When to Prune

Suggested recommendations are listed in detail in crop canopy management calendars. Avocados are light pruned during the latter stages of the spring flush but mostly in midsummer 3-4 weeks after the main summer flush commences. Provided trees have been pruned back to the desired shape from year 2, little fruit will be removed as it will be back inside the outer tree canopy. Pruning back summer flush allows light into the tree and encourages the development of fruiting wood within the inner framework.

Mangoes and Lychee are basically outside tip pruned back to the desired tree shape, and size immediately after harvest to bring the entire tree, into a uniform regrowth cycle in late summer.

5. Major Limb Removal (window pruning)

This is carried out in early flowering to partially rejuvenate the tree by selectively removing a major vertical upright limb to make the tree less complex from year 5-6 onwards. A maximum of 15-20% of total tree only should be removed otherwise excessive vegetative growth and fruit drop may result during the following late spring/early summer growth flush. Any excessive vegetative growth must be selectively pruned as necessary. However removing the correct amount of major limb during winter should result in low vigour growth coming back evenly over the entire tree after fruit set with the spring growth flush, and some watershoot development regrowing with the summer flush. Repeated major limb removal means some watershoots  must be allowed to regrow to eventually replace major limbs during summer.

6. Restricting Root Development in Fertile Soils as an Aid to Canopy Management

Controlling tree growth in highly fertile soils in hot subtropical climates can be difficult. In Mexico, Florida and South Africa, various methods are employed to restrict root development, that in turn aid in canopy management and strong vegetative growth control. In hot dry areas, controlling irrigation and water distribution effectively restricts root system development and coupled with fertigation, gives the desired result.

Deep ripping, an essential part of land preparation for any fruit tree planting, in particular Avocados, can be a very effective means of restricting root development. By only ripping with a single ripper down to 0.5m or by double tynes 30cm apart down to only 30cm in very fertile volcanic soils works well. Conversely in shallow soils or poorly aerated infertile soils, deep ripping preplant on a 0.5 metre cross grid to a depth of lm+ can mean the difference between successful rapid establishment of young trees or slow, erratic growth and poor long term productivity.

7. Natural Restrictive Root Development Effect of Shallow Soils

In Florida, solid ‘coral’ deposits are machine trenched along the row and across the row. Trenches are approx. lm wide and lm deep. Trees are planted where trenches cross. The result is trees can only grow to a certain size as they are virtually growing in ‘a pot’ with highly restricted root area and regular rejuvenation pruning must be carried out to produce new growth and corresponding fruit production.

This same principle applies with most soils that have ‘a bottom’ or an impervious clay, sandstone or rock ‘C’ horizon 1-2-3m below ground level and explains why so many unpruned subtropical fruit orchards become non-productive after a given period of time depending on available soil depth.

Canopy management practices are easier to apply in shallow soils that aid in the control of tree size when trees reach a maximum size relevant to soil depth.

Summary of recommendations

1. Increase complexity of small trees for heavy early fruiting 2. Promote and develop multi leader growth habit for future major limb removal after year 5-6 3. Maintaining desired tree shape from year 2 4. How and when to prune – crop canopy management calendars 5. Major limb removal

6. Restricting soil preparation and root development as an aid to canopy management

Conclusions

Growers planting permanent high density orchards must look closely at the overall concept and implement the total canopy management package to achieve success. Varietal selection, planting density, row direction, correct soil preparation, well balanced nutrition both pre and post planting, and application of correct pruning techniques at the correct time all must fit together to achieve success.

Long term canopy management systems operating in high density orchards in Israel and Florida and more recent research being carried out in South Africa indicates that success can be achieved. Systems and methods employed in manipulating high density orchards must be easily understood and easy to do for industry to adopt them as a standard practice. It is hoped this paper has addressed some of these issues to give growers the confidence to venture into canopy management of high density subtropical fruit orchards Avocado, Lychee and Mango.

References

Stassen, P.l.C. and Davie, S.J. (1996). Principles of a Tree Management Programme. Institute for Tropical and Subtropical Crops Information Bulletin No. 285. Goren, M. and Gazit, S. (1992). Small-Statured Litchi Orchards; A New Approach to the Growing of Litchi. ACTA Hort.349:69-72. Middleton,S.G. (1996). Theoretical/Practical Design of Orchards – Proceedings of the 4’h National Lychee Seminar, Australia, pp 24-29 Wolstenholine, B.N. and Whiley, A-W. (1996). Strategies for Maximising Avocado Productivity – A Review. World Avocado Conference III Israel.

Snijder, B. and Stassen, P.J.C. Manipulation of Hass Avocado Trees – Pruning – A Progress Report. South African Avocado Growers Association Yearbook, pp 73-76.

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Australian tropical fruit orchards are traditionally grown on flat or slightly undulating land. This is primarily because of the costs of harvesting and tree management – a large expense given our high labour costs. In Thailand however, their good flat agricultural land is used for rice and vegetable production and the hillsides are reserved for fruit tree orchards. Obviously the low labour costs make this possible. Khun Pradoldej Kalayanamit, the largest lychee grower in Thailand with 8 lychee orchards, is also a mango, tangerine and strawberry grower. He told me he pays his workers 75 baht a day (about A$3.10) for a dawn to dusk workday and has about 10 full time workers per farm. The all year round jobs such as slashing, spraying, watering and pruning are all then done by hand at little expense to the grower.

Watering

I observed several methods of watering in Thai orchards. Several lychee farms, as well as some mango and longan orchards I inspected, dug a shallow pit around each tree on the drip line, which was then filled with water by buckets. Other orchardists in the Thaton / Fang area whose trees are often grown on 50 degree slopes, pump water to the top of the slope and simply let the water run down the hill. Many of the more affluent orchardists used under tree irrigation, but used tall aluminium stand pipes (2 – 3 m) to spray high up in the tree. They claimed this spread the water further and also added humidity to the air at the important ripening time, when fruit can dehydrate quickly, if not watered sufficiently. All farmers watered regularly but in small volumes. While most agreed to my way of thinking that water application was most important during early fruit set when cell division and development were taking place and again on colouring of the fruit, few seemed to use practices to take this into account. The bucket brigade watered “when the soil dried out” and I had little faith in flooding from the top of the hill. However the farmers with a regulated and controlled system (under tree irrigation) most often explained they watered for one hour every three days. Couple this with an 80 litre per hour microjet, and each tree only got about 200 litres per week! I regularly give my trees between 750 – 1000 litres per week, but in one single application, increasing this to 1500 litres per week during the rapid fruit enlargement just prior to harvest. Tests carried out in Australia several years ago indicated that water stress on bearing lychee trees had little bearing until the last 4 weeks before harvest, when fruit failed to develop to any size, and a lot of fruit was dropped by the stressed tree. As this does not seem to be a common problem to the Thai growers, there must be some other factors at work in Thai orchards. Further investigation is warranted on this apparent inconsistency.

Fertilising

As is the case in Australian orchards, fertilising of lychee trees was dependent very much on the soil types on which the trees were growing and the weather and rainfall statistics for the area. To grow trees successfully, free draining and not overly rich soils were needed, so that the supply of water and nutrients could be more or less controlled, especially in the all important pre-flowering time. All Thai farmers used a complete N-P-K fertiliser, with the most common one observed being a 15-15-15 mix. Application time was late March – early April when fruit was at pea size, with the rate being 1 kg per metre of tree height. Most farmers also used a foliar spray once a week for 3 weeks before panicle emergence. These rates were increased significantly for the few growers with orchards on the flat land, especially if they were on river flats.

While the use of fertigation is becoming increasingly popular in Australian orchards, I only saw one instance of this practice in Thailand. This was at the huge Boonrawd orchard near Chiang Rai in Northern Thailand. Owned by a major brewery in Thailand, money was not a limiting factor, so that recently sourced overseas technology was rapidly integrated into the whole farming enterprise. Here a 10-52-17 mix at 2500 parts per million was applied in two applications totalling 3kg. The first application was made just before the rainy season and the second during the rain. It was interesting to note the poor crop on these trees, which the owners attributed to the adverse weather conditions. My own experience however, would suggest that applying fertiliser both before and during periods of heavy rain would be counter productive, with the fertiliser being washed away or carried so far down into the sub-soils as to be unavailable to the shallow rooted lychee trees.

In summary then, Thai farmers operated under a similar belief to Australian growers, that is you fertilise to produce bigger and better fruit, rather than bigger trees. Fertilising both before and after fruit set is now widely practised in both countries, in the expectation that after harvest when trees are nearly drained in regard to available nutrients, the wet weather will result in only one or at the most two post harvest flushes, so that trees are kept smaller and in a fruiting rather than flushing state.

The use of organic fertilisers, though only practised by a small number of farmers at present, is, according to one grower I spoke to in Lamphun in Chiang Mai province, increasing rapidly. He uses a system called EM (essential micro-organisms) that he buys in from Japan. The make up of this liquid is kept secret by the Japanese, but is claimed to be a mix of soil health promoting organisms that replace the need for any fertiliser application. This product is mixed in to rice husks, animal manure and whatever other biodegradable product is available, has molasses poured over it and is then left for three days covered with hessian bags. There was obviously some reaction taking place, as this mixture was very warm to the touch, even though it was in the shade of a large shed. This is then used as fertiliser at the rate of 10kg per tree 3 times a year. Neem oil mixed with the EM is also used as an insecticide whenever necessary. The farmer claimed he produced the biggest and best fruit in his area and was rapidly convincing more and more of his fellow growers to switch to his methods. Unfortunately I could not see any of his fruit because he had already completed his harvest and neither could I see his trees as his paddock was too wet! Perhaps some follow up visits may be appropriate when I am next in that area.

Flowering induction

In Australia at present, getting trees to flower regularly and heavily takes up most discussion whenever lychee growers get together. This is especially a problem on the hotter and wetter coastal regions, rather than on the cooler Tablelands region where I grow these delicious fruit. Flower induction is brought about by a combination of two factors – the point of growth of the tree and the weather. The first of these we can try to control, the second we cannot. The ultimate is to have your trees just starting a new growth cycle as the cold weather starts. This means having buds around the 1-3 mm size with the arrival of cold weather (< 15 degrees C) during the night, and in the low 20’s during the day. Buds bigger than 3mm will result in either all new growth or a mixture of leaf and flower and if the trees are not in a growth cycle and are dormant, they will likely stay dormant until the warmer weather arrives again and then be vegetative. Farmers in Thailand have similar problems and have developed several methods to ensure they have good flowering at least 9 years out of 10. These are cincturing, the use of potassium phosphate and the use of potassium chlorate, calcium chlorate or sodium chlorate. This method requires further investigation in the warmer growing areas of Queensland where flowering can often be irregular. Initial attempts at this practice have proved unsuccessful in Queensland in the one large scale trial that was conducted. However on talking to the grower involved in this, I believe the timing, so critical in this exercise, was not correct. While not being necessary on my own farm where I can more easily control growth, such a process needs to be revisited on coastal orchards in Northern and Southern Queensland. Already several growers in these areas to whom I have spoken, or who saw the process themselves when I took a group of growers to Thailand in May, 1999, have decided to put the process into practise on small areas of their own orchards for evaluation.

Depending on tree vigour and water availability, lychee trees can continue growth cycles well after the desired one or two flushes following the post harvest wet season. This dramatically increases the chances of trees being in a growth or hardening off stage with the onset of colder weather, resulting in little or no flowering. This was a particularly bad problem in the Chiang Rai province of Thailand.

Cincturing and Potassium Phosphate

This is a method also practised in Vietnam and China, where trees are ‘ringbarked’ to stop all vegetative growth. Each tree in an orchard has a narrow cut made around each branch after the tree has divided into the 4 – 6 branch stage. This cut must be very precise as far as depth is concerned, because if it is too shallow nothing is achieved and too deep and the branch dies. This is why individual branches and not the whole trunk is cinctured – better to lose one branch rather than the whole tree. The cut must go down to the cambium layer and no deeper. This has the effect of stopping the trees growth, with all its energy put into repairing the damaged section. Once this repair has been made, the tree switches back into a growth cycle. The Thai farmers, with assistance from their agricultural advisers, have found that if they cincture their trees in October each year, the exact date depending on their area, the trees will take around two months to repair themselves and then start a new growth cycle just in time for the new Thai winter, so that flower initiation occurs in January. Chiang Rai Horticultural Research Station set out to find an easy solution for growers of large orchards where cincturing was not realistic.

Researchers there have found the use of the chemical potassium phosphate goes a long way to solving this problem. The chemical is applied through a misting machine at 5000 parts per million at 7 day intervals for 2 or 3 times, about 6 weeks before anticipated cold weather (and flowering). This has the effect of hardening off any flush on the trees in only 2 or 3 weeks, much shorter than the normal 5 – 6 weeks and putting the trees into a dormancy stage – exactly what you want. Then with careful manipulation of water, you can induce flowering at the right time. A fellow lychee grower in Sarina has already put this process into effect on his own property, because when he arrived home from Thailand with me, he found his trees covered in a brilliant flush. He immediately applied potassium phosphate, the flush hardened off quickly and his trees are now flowering well. The process seems to work well and further research is needed into its causes and long term effects. Growers now have some hope of generating flowering on trees that are overly vigorous at the wrong times in the year, trees, which dutifully flowered 6 weeks later, and then set fruit. I ate about 2 dozen of these fruit when I visited his home (he would not let me eat too many, because they were making him a fortune, being out of season) and we then inspected his nearby orchards where the chemical had been applied at the usual time. These trees were covered in the most beautiful flowering you could imagine and he was expecting a crop of around 50 tonnes (A$165 000). All the longan orchards in Thailand used this chemical, although no one else mentioned the out of season application to induce flowering.

Opinions varied as to the best way to apply the chemical, with most farmers preferring the ground application method. One farmer I visited in Chiang Mai province physically raked all the litter and mulch out from beneath his trees before applying the potassium chlorate. He did this to aid absorption of the chemical into the ground. The litter was then raked back into place. However the results seemed to be worth the trouble. His 1000 five year old trees had a magnificent crop of fruit, which he estimated at 75 tonne, worth A$250 000. In Chiang Mai I had the privilege of having dinner and a long discussion with two Thai horticultural advisers. They were private consultants working mainly in Cambodia, who informed me that both calcium and sodium chlorate were both just as effective as potassium chlorate in this process, but claimed foliar application was more effective than ground application. Their recommended spraying rate was 50g per metre of canopy (ie a 3m tree requires 150g), six weeks before expected flowering. This matched exactly the rates given by the Chiang Mai farmer discussed above, who claimed to use 150g per tree on his trees of 3 to 4 metres. (They also showed me pictures of high density apple orchards in Cambodia with 36 000 trees per acre. They were harvested like sugar cane and simply left to reshoot from the stump). The use of these chemicals in promoting flowering in lychees is now just starting to be investigated in Thailand. One large grower in Thaton tried it for the first time this past year and did not notice any appreciable difference in these trees compared to his others, as they all flowered well anyway. This year he is going to apply the chemical earlier to see if he can induce an early flowering and has promised to keep me informed of the results. Should such a process be as successful in lychee as it appears to be in longan, the potential for further development would be enormous.

Pruning

This process has been occupying the thoughts of Australian growers for several years now, as the Canopy Management Research team, with funds from the Australian Lychee Growers (ALGA) and the Horticultural Industry Research Development Council (HIRDC) have looked for ways to control canopy size in lychee trees, while maintaining production. For this reason, I was particularly interested to see how growers in Thailand pruned their trees to keep them manageable. The major point I gained from many growers with whom I spoke about this was prune immediately after harvest and heavily. This was best illustrated with a visit to a small orchard at Mae Sai in the Golden Triangle area. His pruning theory was to remove all upwardly growing branches immediately after harvest, leaving his trees in a hollow mushroom shape. The trees then flush heavily for 2 flushes, at which time they are cinctured to prevent further flushes. He claimed figures of 200kg per tree on a regular basis, however I visited his orchard just after harvest and could not see this for myself. I did see his pruning taking place and may attempt his method on some of my larger trees in the near future. Other growers pruned the top out of their trees one year and the sides the next, claiming this was less stressful on the trees than a full prune each year. From what I have seen both overseas and in Australia, I would suggest that pruning, whether it be light or heavy, doesn’t really matter as long as it is done straight after harvest and the trees are encouraged to flush heavily after that. The trick is to manage to stop them in time to provide a period of dormancy before flowering should commence.

Harvesting, Transporting and Processing the Fruit

While some similarities were evident in the Thai harvesting exercise, there were a great many differences. Thai farmers only picked from sunrise to around 10am, but whether this was to promote shelf life as is the case in Australia, or to meet deadlines for transport was not explained. Once in the packing shed the differences were considerable. The Thais use no machinery – all work is done by hand, mostly using imported Burmese people at around A$2 a day. The fruit panicles are roughly graded and split or damaged fruit removed. The fruit is packed still on the panicle into 10 kg boxes, but not refrigerated. The whole process must be completed before 12:30pm, when the fruit is loaded onto a truck to be taken to the nearby depot, where it is loaded aboard a larger truck that leaves for Bangkok at 1:00pm. Here it arrives at the markets in the early hours of the morning, where it is sold that day. There is no need for refrigeration facilities due to the rapid turnover of the fruit. Thai people adore lychee – they are no sooner on the shop shelves than they are walking out the door, so that new stock is required each day in large quantities.

Thai supermarkets also have a very low mark up on local fruits, so that they may compete with the hundreds of street vendors also selling fruit. This of course helps to ensure rapid turnover and fresh product each day. A visit to Talad Thai, the newest and largest Fruit and Vegetable Market in Bangkok, confirmed this. Despite the huge range of fruits available, it seemed every buyer there made sure they had lychee on their list. At 250 baht per 10kg box (farmers were getting between 17 and 19 baht per kilo) the fruit was very inexpensive by Australian standards, but the supermarkets were still retailing them at only 30 to 35 baht per kilo.

Fruit rejected at the farms as not suitable for fresh sale is sent to one of several canneries in the lychee growing areas. On a visit to such a cannery on the outskirts of Chiang Rai, I witnessed this lower grade fruit being processed into canned fruit, boiled down into syrup for the canned product or processed into juice. Nothing was wasted. The wage structures in Australia would preclude such an operation on a seasonal fruit being set up here. Instead our reject fruit is dumped on the ground to rot and be used as mulch – one of the prices we pay for growing a seasonal crop in a rich industrialised country

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The qualities of the Rosella (Hibiscus sabdariffa L. Malvaceae) (otherwise known as roselle or Jamaican Sorrel) are not well known by many home gardeners. Rosella may be considered a bit of a novelty for jam-making, but its other qualities and uses are not well appreciated. As we have found out this summer, the rosella can be used for much more than the traditional jam or jelly. Its flavour as a stewed fruit is superb – something like rhubarb, with a hint of cranberry and plum. It is delicious with yoghurt or ice-cream. Add to this the fact that rosella is hardy and easy to grow, productive, perfectly adapted to a subtropical climate, and you have a perfect garden fruit for South East Queensland.

Description

Rosella is an annual member of mallow family, growing in warm temperate to tropical areas. Sow in spring, mature after 9 weeks. Rosella is an erect, bushy, herbaceous shrub which can grow to heights of 2 m. It is a short-day plant and photoperiodic, which means that it won’t begin flowering until the days are shortening. In South East Queensland, plant in spring, and flowering will start in January – February, with harvest from March – May. Harvesting causes latent buds to develop and extends the flowering life of the plant. It is native from India to Malaysia, where it is commonly cultivated, and is now common in Africa, the Tropics and Subtropics of both hemispheres, and in many areas of the West Indies and Central America has become naturalised.

There is also a native rosella H. heterophyllus which is found all along the east coast of Australia from central N.S.W. up to the Lockhart River. It is larger plant, up to 5 metres. In South East Queensland it has white flowers. Its uses are similar to the true rosella, and it has been described as a versatile vegetable, with buds that can be stewed, leaves tasting like sorrel and roots like woody parsnips (see warning below). It prefers a moist open spot but adapts to dry conditions and partial shade.

Uses

The culinary uses of rosella are based on the crimson coloured calyx – the petal-like bracts that develop around the seed buds after the flower drops, and the round green seeds buds themselves. The calyces and buds have many and varied uses. Here’s some of them:

• stew the calyces with sugar as a dessert fruit or filling for tarts or pies
• make sauce, juice or syrup
• steep the calyces of 3 or 4 buds in boiling water for delicious red zinger tea
• make jam, marmalade, relish, chutney or jelly from the calyces and buds. No pectin is needed as the calyces possess 3.2% pectin. Use with puddings, icing, or poured over pancakes, waffles or ice cream
• cook calyces with 1:4 water in ratio to amount of calyces, and use for cold drinks. This may be frozen or bottled in sterilised, sealed bottles or jars. It keeps well providing no sugar has been added.
• For a more zesty drink, put calyces into a jug with a little grated ginger and sugar, pour boiling water over it and letting it stand overnight. The liquid is drained off and served with ice and often with a dash of rum
• make a colourful wine from the juice
• The young leaves and tender stems of rosella can also be eaten raw in salads

Nutritionists have found that rosella calyces are high in calcium, niacin, riboflavin and iron. Seeds also make an good feed for chickens.

Preparation

To prepare rosellas, wash and then make an incision all around the tough base of the calyx below the bracts to free and remove the base with the seed capsule attached. The calyces are then ready for immediate use and the capsule part is used whole as part of the jam or jelly recipes.

Cultivation

Rosellas are suitable for temperate to tropical climates with well-distributed rainfall of 1500–2000 mm yearly, from sea-level to about 600 m altitude. They tolerate a warmer and humid, but are susceptible to damage from frost. Rosellas will adapt to a variety of soils but prefer a permeable soil with humus. It is not shade tolerant. Soil preparation should be deep and thorough. Propagate from seeds and cuttings. Cuttings produce shorter plants but the yield of calyces is relatively low.

Use whatever fertilizer would be ordinarily used for vegetables. Early pruning will increase branching and development of more flowering shoots. Harvest the fruits when they reach a good size but still snap off easily by hand, The lower fruits may require cutting with secateurs.

Rosella’s major enemy is the root-knot nematode, and they should not be planted where this pest is prevalent. In Australia, 3 beetles, Nisotra breweri, Lagris cyanea, and Rhyparida discopunctulata, attack the leaves.

ROSELLA JAM

Ingredients: Rosellas, Sugar, Water

Remove the leaves from rosella pods reserving them. Put the pods into a saucepan and cover with cold water.  Boil 2 hours and strain through gauze. Pour this liquid over the leaves and boil 20 mins. Measure the lot and allow 1 cup warm sugar to 1 cup pulp. Boil smartly 20 mins and bottle as for jams.

NATIVE ROSELLA JELLY

Detach petals from calyx and discard calyx. Chop petals finely and place in a very deep pyrex bowl. Cover petals with lemon juice and microwave on high for 4 minutes. Add boiling water and sugar and stir well. Cook 2 minutes then stir. Cook another 2 minutes, stir and then cook 2 minutes more. Let cool for about 1 hour. When cool, cook for 4 minutes then stir. Cook for a further 2 minutes and stir. Cook 2 minutes more and stir. Let cool slightly and pour into a sterilised jar. Refrigerate before using.

This recipe produces a rich red spread with the consistency of honey. It has a distinctive flavour and is delicious on toast or scones. Can be used as glaze or diluted with white vinegar for sauces or marinades.

Sources:

James A. Duke. 1983. Handbook of Energy Crops. unpublished.

Julia F. Morton Fruits of Warm Climates Published by Julia F. Morton 20534 SW 92 Ct. Miami, FL. 33189 ISBN: 0-9610184-1-0

Colleen Keena. Hibiscus heterophyllus Adapted from an article written for Brisbane Rainforest Action & Information Network BRAIN and published in BRAIN Newsletter 10, January, 1998)

WARNING. It should be noted that although numerous references suggest that no hibiscus is known to be poisonous, Peter Hardwick has expressed concern in relation to native rosella H. heterophyllus. In the Australian Food Plants Study Group Newsletter of February 1995 it was reported he suffered kidney damage from drinking H. heterophyllus tea over a few days and that discussions with Aborigines confirmed that they use this plant only sparingly as a medicinal plant, rather than to eat.

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Any fruit in syrup can be preserved in alcohol and not need refrigeration. The important thing to work out is the percentage of alcohol by volume as this must be kept above 19% to prevent fermentation. What you will end up with is a small amount of fruit in liqueur. Starting with 500 ml of Brandy at 37%, gives 185 ml of alcohol. 1L of product (500mL fruit in syrup and 500mL alcohol) would give 18.5%, 900ml would give 20.5% alcohol by volume so to cover for atmospheric factors add 400 ml of fruit and syrup to 500 ml of spirit (rum, brandy, vodka, scotch).

The balance of the finished product will be affected by the balance of sugar to alcohol. With sweet fruit work on 185g of sugar in your 400 ml of syrup. More fruit can be added and less sugar if the fruit is extra sweet. I start with equal weight of fruit to sugar giving a slightly higher sugar content, so mix 200 g of fruit to 185g to 200g of sugar, leave for 24 hours to liquefy – if no liquid (a dry type fruit) add a scant amount of water and heat gently (while stirring) to above 70 degrees Celsius for 15 minutes to sterilize the syrup and liquefy the sugar. When the syrup is cool blend 400ml of fruit in syrup with the spirits, bottle and place in a dark storage space and allow to mature. The more years you leave the product the thicker it will get.

The same can effectively be done by adding dried fruit to spirit. At a guess I would add 400 g of dried fruit to the alcohol and allow to rest in a sealed jar for 12 months or longer. The longer this is kept the fruit will absorb almost all of the liquid and you will end up with a very alcoholic fruit mince for cakes. I used to keep mixed dried fruit in rum in a jar to add to cooking, just adding a spoon or two, or three to cooking as needed. With all of these the true test and trick is to mature them for at least 12 months.

Authored by: 

John King of Rainforest Liqueurs – http://www.rainforestliqueurs.com.au/

Sourced from: 

Sub-Tropical Fruit Club of Qld newsletter June July 2002

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Tino: I’ve been in the area since 1950 growing grapes – some of you from around here will remember that Richlands was a big grape-growing area in the 50’s 60’s & 70’s. The main varieties grown were the Black Hamburg and Cloach. They have now fallen out of favour and we took up new varieties in the 80’s. Grapes will grow in a wide range of soils from sandy loams to the heavier soils. They need two things – a reasonable winter – the colder the better – and good drainage. If you grow them around your house, I’d recommend the northern aspect because they need full sun for good results. We have 12 varieties here and a few wine grapes for our own use. Some varieties we have are Cardinals, White & Black Muscat, and Maroo Seedless. We chopped out the Menindee Seedless because we couldn’t get them to bear in this area – they tasted like apples but people liked them.

We graft onto our own rootstock here though grapes will grow on their own roots. You can just plant a cutting but it depends on the area. If you have red soil or you’re inland, they would probably grow quite well on their own roots. It’s really the nematodes that knock them around. We had no success with that here, so we graft them. There are a large number of rootstocks available (check with the DPI). On our farm we’ve experimented with about 15 and the best was called SO4. They’ve changed its name to Telechi 5C. That’s the rootstock we use. It’s vigorous, but not too vigorous, and we have good results, finding it compatible with most varieties. Some rootstock is not compatible with particular varieties. Ramsay, a very vigorous rootstock, is one to watch. It wasn’t compatible with some of the varieties. You’d put it in and they would grow for a year or two then die. So, rootstocks are very important.

The most critical part of the growing is the controlling both Downy and Powdery Mildews. To control them you use Copper and Sulphur. There are a wide variety of Coppers – Copper Oxychloride or Mancozeb and Wettable Sulphur. In the old days we used Bordeaux Mixture, which was copper and lime mixed together. It was probably the best ever. It was rain resistant. It did take some effort to mix and it is not compatible with a lot of other sprays. Rather than keep spraying with Rogor or Lebacyd for the fruit fly we use an attractant that we spray – we trickle it on every 4^th row. We mix an insecticide with the attractant that draws the fruit flies to it. They eat it and it’s the end of them. We spray it once before the grapes ripen, then every seven days after that. That has given us good control over the fruit fly. You have to spray for Mildews especially in a wet year. If you don’t get any grapes, it’s because you have mildew. Work is being done to develop Mildew resistant varieties – one of them is Chamboucin. It’s a wine grape. I’m experimenting with them, and they seem to be quite clean and don’t get Mildew. Another important thing with grapes is fertilising – we use Nitrophoska – have a look at your growth – if you’re getting good growth, then you don’t need too much fertiliser. Apply it sparingly.

Member: Which is the best mildew-resistant variety?

Tino: Probably Isabella and Chamboucin.

Tino: We had to net all the vines last year because of birds.

Sheryl: What are the water requirements for grapes?

Tino: We’re not geared to water – we have a bore and we put a bit of water on if it’s really dry but they do quite well without water. I must stress that we cultivate our soil. DPI will tell you that’s not the way to go – they’ll say grass it and keep it clean on the side and that’s OK if you have plenty of water to give them. To cultivate, we use a Triple-K cultivator once we’ve cleaned out the off-seasons undergrowth. That normally digs down about 10cm and it keeps the soil loose, forming a buffer from the hot sun and preventing moisture being drawn out from underneath.

Bruce: For those of you who don’t understand, you may wonder why that’s working. If you don’t cultivate, the grape will have its roots near the surface, in the top few inches.  Then when it becomes really dry, the grape becomes too dependent on those surface roots. It will dry out. Whereas, what Tino is doing is effectively creating a kind of mulch. By disturbing the surface soil each time, and cutting out roots that crept towards the surface, the grape doesn’t become dependant on surface moisture. In the summer the surface will dry out, but there is water that will stay down lower. He’s altered the soil structure so it doesn’t actually act with a capillary action, sucking water up from deep below and allowing it to evaporate.

Tino: We’ve dug holes 1m deep and you couldn’t get the dirt up with the shovel because it gets so powdery deep down. If you don’t cultivate and keep that buffer between the moisture under the ground and the sun, it will dry out.

Sheryl: How do you know when to start irrigating – when the leaf starts wilting?

Tino: If you wait until that, you may as well forget it!

Sheryl: What do you use as an attractant for Fruit Flies and what do you add to it?

Tino: We use Q Fly Lure. It tells you what to use with it.  We use it with Lorsban.

George: How often do you put it on?

Tino: We put it on before the grapes ripen – about every 7 days – we trickle it on top of the leaf cover. It doesn’t go anywhere near the fruit – that’s the beauty of it.

Sheryl: What time of the year do you fertilise?

Tino: We fertilise after they shoot, and we use Potassium Sulphate as well when the berries have formed

Sheryl: How much do you use?

Tino: Use it sparingly.

Bob: What nets do you use?

Tino: We use cotton/nylon – they’re very good. We started off with plastic that was supposedly biodegradable. We use rolls of 5m by 150m. You could try buying them from Growforce, although you can only buy them in bulk. They will keep the silvereyes out, and you should get 20 years of use out of them. We made up an attachment to put them on and take them off.  It’s a bit of a contraption that goes behind the tractor and makes the net go through some loops. It requires 3 people to manage netting – one driving, and two walking behind to put them on. It is the same when taking them off.

Bob: What happens when the vine grows through the net?

Tino: We only put them on just before they ripen. To free the vines, we slip a 1 inch water hose under the net, and, one on each side of the row, my brother and I, walk along every row. We do this every 3 weeks or so and it flicks the nets up. Don’t leave them on too long or the new shoots will go through the netting.  The first couple of years when we had finished with the nets, we tried to roll them up but that was not successful so we coded each patch of grapes and we bag the net in coded bags ready for next years use. 

Tino: When pruning, the idea is that the shoots you leave this year are on last year’s wood – all grape-bearing shoots have to be on that wood.  The problem is that if you cut back and it’s not on last year’s wood, the fruit won’t form. One other important thing is to always keep the vine coming back. 

Peter: There’s a fair amount of energy stored in the wood as well as the roots so why don’t grape growers leave a fair amount of wood there?

Tino: We could leave an enormous amount of wood and we’d get an enormous amount of grapes but they wouldn’t be first quality grapes  A typical example would be Black Muscat – you can get a box of grapes on a vine of this type, but the colour wouldn’t be black, it would be wishy-washy and the taste wouldn’t be there.  We work on 3-5kgs per vine and this gives good quality fruit, as the nutrients go into your existing bunches of grapes. There are 2 ways of pruning. Spur and rod pruning – when you’re pruning you have to think 3 years ahead. With the Black Muscat on our farm, no grapes will come out on the spurs – only the rods will bear. The difference between a rod and a spur is – a rod is a long cane of 8 to 10 buds; and a spur has only two buds.

Sheryl: Do you prune every variety the same?

Tino: No. Merbane I prune differently. Wine grapes I also prune differently – instead of one rod, I’ve been leaving two. The spacing between vines is 1½ metres. We don’t irrigate. When pruning, I only leave 2 rods – one each side.

Sheryl: With North to South and East to West directions, do you have different varieties going East to West as opposed to North to South?  

Tino: If you get a really hot summer then East to West would be an advantage because grapes do burn. Planted East to West they are shaded underneath. If they are planted North to South they can cook on a hot sunny afternoon. We have Black Muscats going East to West and there’s not a lot of difference between those, but in a backyard situation, you’d plant them on the Northern aspect of the house. That is, the trellis would run East to West. We graft all varieties just below ground.  We only grow table grapes commercially, and I dabble in a bit of wine grapes for my own use.

Sheryl: They’ve got a higher sugar content haven’t they?

Tino: The only way to get the sugar into them is not to overload your vine with berries, and if you get a reasonable season allow them to fully ripen. The only reason you can’t get decent grapes at the market is because it’s a falling market and the grower tries to earn as much as he can. So if it looks good, he picks it early. If you can’t eat it, you shouldn’t be picking it and the reason we have a bit of a following here is the very reason that they taste good.

Bruce: I can vouch for Tino’s Muscat grapes making a dry wine you get 14% alcohol – plenty of sugar in them.

Bob: My father knew somebody who used to plant the wild rootstock, and then he’d dig down underneath the ground and graft it then cover it over with newspaper and soil and keep it damp.

Member: That was before they had tape.

Peter: Are the rootstocks you use resistant to phylloxera?

Tino: All rootstocks released by the DPI are phylloxera resistant. There was a small area on the other side of the river with phylloxera but we’ve never had it here. We put in a cover crop, Sudex. It grows right up over the posts. We slash it twice and it puts mulch back into the ground and stops the soil wash. Also, if you get the heavier rains earlier in the year, it helps to drain the soil. We plant it after we finish taking off the crop in late January. Drainage is a most important thing.  We’ve had some problems. We found that if you over-fertilise they grow too lush, and they tend to split. We found that by getting them to grow hardier, they’ll stand up better to all conditions. Cardinal will split but the Muscat should be fairly split resistant.

Member: I have Black Opal, and if I get heavy dew in late April, they split.

Tino: They’ve changed its name to Black Maroo – we have 6 rows of those.

Sheryl: Why do you graft below ground?

Tino: Our soil was originally more acid than is ideal for growing grapes. In the early days we added dolomite annually to correct the acidity. Now that the pH (a measure of acidity/alkalinity) is up to about 6.5 (almost neutral), we haven’t applied dolomite for some years. Grapes will grow if the pH is between 5.5 and 6.0. For many years we applied dolomite at a rate of 10 to 15 tons per acre. We used dolomite rather than lime because first, it includes magnesium as well as calcium; and second its action on the soil and soil microorganisms is gentler than lime. Most organic gardeners prefer dolomite to lime.

Article compiled by Sheryl Backhouse

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For Apricots, Pears, Plums and Peaches – mince and add sodium or potassium metabisulphite from the chemist.  For 12 lb of fruit, wash and remove the stones/seeds and other waste then mince into a paste.  Add ¼ oz or about a teaspoon of the sodium or potassium metabisulphite, stirring in well to give it an even distribution through the mixed pulp.

Spread on drying trays or plastic sheets and place in the sun. Each strip should be ½ to ¾ inch thick and six inches wide. Use a pot scraper to spread food evenly and square edges. Leave in the sun at least a day to fix colour. After that, drying can be completed in sun or shade. After 3 days, turn the strips to hasten drying. When dry, roll into strips and store in airtight containers.

You can catch up with Chester Dott from Forbidden Fruits Nursery Mullumbimby at one of the markets in northern NSW:

1^st Sunday Byron Bay;    2^nd Sunday The Channon;    3^rd Saturday Bellingen;    4^th Sunday Bangalow

Ring for a copy of his list or email: forbiddenfruits@optusnet.com.au for a copy.

Sourced from: 

STFC Newsletter February – March 2006

Date sourced: 

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So our local newspaper proclaims! Tequila is an alcoholic beverage prepared from the leafless cores of various types of agave in statutorily-defined areas of Mexico, where it is a native plant.  One USA botanical source lists over 1350 recorded names of species of agave, but the preferred species for top-quality tequila is the blue agave – Agave tequilana Weber (blue variety).  Even then, this particular agave has many subspecies and varieties. 

There are four main types of tequila, with varying percentages of alcohol.  Some may have involved the addition of non-agave sugars, colourings or flavourings such as caramel, and have been subjected to different periods and methods of aging.  The acknowledged best and clearest, but most expensive, white or “blanco” tequila, is aged for the least time – less than 60 days. Whether it or cheaper types will be the “new vodka” remains to be seen.

Tequila is familiar to drinkers in bars round the world as the basis of margaritas. Margaritas consist of white tequila, mixed with an orange liqueur such as Triple Sec, Cointreau or Grand Marnier, and lime juice (preferably from fresh limes). The rim of the glass can be moistened with lime juice and then dipped in salt.  A lime wedge set across the rim completes the presentation.  However, tequila does not contain the well-publicised preserved worm inside the bottle – this is found in a similar product called Mezcal, which is prepared from one or more other types of agave, to which is often added a preserved larva of one of at least two insect species found within the plant. Tequila and vodka are sometimes combined in cocktails, but which will be most popular and affordable in the long term remains to be seen. The traditional preparation of tequila did not include distillation, so the usual alcohol content was only 5%-7% or so.  However, when the Spanish Conquistadores arrived in Mexico, far from their ready supplies of familiar liquors, they introduced distillation and so a much stronger spirit could be produced. The Mexican legal limit to alcohol in tequila is 38%-55% but the lower end of this range is most common. Production is labour-intensive at times during the 8-12 years it takes the blue agave to approach maturity.  Offshoots arising from the base of the plant are taken to provide new plants. This is because the developing flower spike is cut off a few months before it is ready to emerge from the core, which subsequently swells and becomes sugar-enriched, a desirable quality for alcohol production.  The leaves are cut off during harvesting of the core, which can weigh over 50 kg. Shredding, roasting (or steaming) milling and fermenting are followed, in commercial production, by distillation and then blending to standardize the flavour of particular brands.

The high prices asked for bottled tequila do not reflect the poor cash return to the Mexican growers, who have suffered recent boom and bust periods, with some crops affected by serious epidemics of fungal and bacterial diseases.  The Mexican authorities seem to be just as protective as the wine-growers of the Champagne district of France of the name of their important local product, and the areas in which it can legally be grown. This, together with the lengthy period before a crop can be harvested, its size and quality depending on climate and soils, and the technicalities of processing, would surely discourage any serious tequila fancier from embarking on a do-it-yourself project.

It may be of interest that a rather similar member of the Agavaceae,  Furcraea foetida, a mistakenly-labelled, weedy species which grew in our back garden for about 25 years, allowed us to secure a current record in the Guinness Book of Records in 2002 for the tallest inflorescence ever recorded. It towered for almost 40 feet, on top of a further five feet or so of the substantial leafy base.  The long-awaited, sudden emergence of the flowering stem and the rate at which it grew each day were remarkable.  It beat the previous record, for an unrelated species, by about five feet, but we are sure there are still-taller relatives out there somewhere. Further information can be found in books such as:

Lawrence Kretchmer “Guide to Tequila” and Lance Cutler’s “The Tequila Lover’s Guide to Mexico”.

Also, a very exhaustive review with links to further information is available at: http://www.ianchadwick.cm/tequila/news.html.

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A great success in our vegetable garden over the last couple of years, is the perennial capsicum (it actually isn’t truly perennial, but lasts 3 – 4 years in the sub-tropics). Although small, the sweet capsicums have the distinct advantage that they don’t get stung by fruit fly and don’t get rotting patches as the big ones sometimes do in summer. In this respect they are rather like cherry tomatoes – much easier to grow than their larger cousins but just as tasty!

 Our bush is over two years old, and is about 80cm high, forming a clump about 1m across. It has developed a thick, gnarled trunk .The 8cm long fruit are shaped like a pointed chilli, but are sweet, not hot. They are formed all year round, and they can be picked green or left to ripen on the bush until bright red. The bush gets a bit of compost thrown around the base when I think of it, but otherwise it looks after itself in our veggie patch, which is regularly watered.

 A great use for the little pointed capsicums is to puree them when red and sieve the puree to remove the ‘plasticky’ skins (I put it through a mouli). Then freeze the puree in ice cube trays, empty the frozen cubes into a freezer bag, and use as required. It tastes really great added to chilli beans, spaghetti sauce or casseroles, as well as adding a lovely rich red colour. This is a vegetable I really recommend growing – it seems to love a subtropical climate and has become a permanent feature in our garden. The capsicums are always there on the bush whenever a recipe calls for them.

 The seeds came from Eden Seeds originally, so it is a non-hybrid. Eden Seeds have some wonderful old-fashioned varieties – you can contact them on www.edenseeds.com.au or phone 07 5533 1107

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• Peanuts   If you know someone who has a child who is allergic to peanuts, you must eliminate all soy from the diet. Other risk factors are other food allergies, a family history of peanut or soy allergies, a diagnosis of asthma, rhinitis or eczema or a family history of these diseases. Source: Letter from Ingrid Malmheden Yman PhD, Senior Chemist, Sweden National Food Administration to the New Zealand Ministry of Health 30/5/77. Soy goes by many aliases. If you are one of those that checks food labels then food processors are less likely to list “soy” than a technical term such as “textured vegetable protein (TVP)” textured plant protein, hydrolysed vegetable protein (HVP), vegetable protein concentrate, vegetable oil, vegetable broth, bouillon, natural flavour or mono-diglyceride that do not necessarily but are likely to come from soy. There’s an article on Soy by K.T. Daniel who is the author of “The Whole Soy Story: The Dark Side of America’s Favourite Health Food. The author is a board-certified clinical nutritionist.  Ref:  Ingrid Malmheden Yman PhD, Senior Chemist, Sweden National Food Administration to the New Zealand Ministry of Health 30/5/77
• Peanuts  Interesting news from Dr. Andy Clark. A team of British scientists have come one step closer to curing nut allergies after a small-scale clinical trial in which they successfully built up children’s tolerance to peanuts. Researchers at Addenbroke’s Hospital in Cambridge, England, gave small daily doses of peanut flour to four children who were severely allergic to peanuts, building up the amount over time. By the end of the trial, each child could ingest at least 10 peanuts without having any reaction which the scientists noted was more than enough to protect against any accidental ingestion through nut-contaminated foods. In the study, published in the journal Allergy, four children were initially given five milligrams of peanut flour mixed into yoghurt. Over the next six months, the dose was increased every fortnight until they could tolerate at least 800 mg — the equivalent of five whole peanuts. The trial is ongoing and 20 children aged seven to 17 are now involved with some able to ingest 12 peanuts a day. However, they must maintain their tolerance by ingesting five peanuts a day, said Andrew Clark, a consultant in paediatric allergy who led the research. “At the moment we know that if they continue to eat five peanuts a day, their tolerance is maintained. If they were to stop, then there is some evidence that tolerance would be lost and they may have a reaction,” he said. They would be monitored for the next three or four years to assess their tolerance levels, Clark said, adding that there was no reason why the clinical trial could not be extended to adults. “For all our participants, a reaction could lead to life-threatening anaphylactic shock. It’s not a permanent cure, but as long as they go on taking a daily dose they should maintain their tolerance,” he said.
• Olive Pollen  If you live in an olive-growing area, don’t be surprised if you start sneezing. A recent NZ Medical Journal Reports that pollen from olive trees is a major cause of respiratory allergy in Mediterranean countries causing the same symptoms as hayfever. The species of olive grown for fruit is Olea europea. It’s one of the Oleaceae family that also contains private (Ligustrum) Lilac (Syringa) and Ash (Fraxinus). Of all the family the olive is considered to have the most allergenic pollen.