SITUATION OF THE CAROB TREE IN AUSTRALIA

SCIENTIFIC NAME: Ceratonia siliqua
FAMILY: Fabaceae

Australia is an important agricultural and livestock producing country that is growing quickly into one of the most aggressive on the world market. The agricultural sector provides 4% of the Gross Domestic Product (GOP), emphasising wool production, meats, cereals, seed oils, sugar, and fruit. In the last few years, Australians have cultivated crops such as the almond, grape, pistachio, macadamia, and citrus. These have increased in cultivation area and, more recently, others such as the olive and the carob are beginning to be considered as new alternatives for some states of the country.

The cultivation of the carob in Australia is still of minor importance although some orchards have been planted, basically in the states of Western Australia and South Australia. The history of this leguminous crop in this continent dates only from the past century.

The first trees were planted around the year 1850, with seeds imported by Afghan, Italian, Greek and Spanish immigrants. The carob was to be used as food for fattening animals which were used for the pulling of cultivation and harvesting implements. The carob is found very scattered in this country, normally in the form of isolated trees in streets, gardens and agricultural developments.

The first commercial orchards were planted in the 1980s and are found in the localities of Burra, Gawler and Loxton (South Australia), and later extending to other areas such as Geraldton, Nabawa, York, etc. in the state of Western Australia. At present there exists some 30,000 widely separated trees, of which half are productive plants with female flowers, and some 170 ha in young orchards, basically in four states of Australia (Table 1); Western Australia with some 110 ha, South Australia with 50 ha, and New South Wales and Victoria with 5 ha each. The principal cultivation zones are located between latitudes 20° and 38° S.

Livestock raising has great importance in Australia, mainly sheep and cattle. This accounts for the interest in the carob as an ingredient of stock fodder. Also it is being increasingly used in the human consumption of some foods, when some components of the fruit are used, such as the "toasted flour of the pulp" in chocolates, biscuits, fruit coating, etc. The 'locust bean gum' that is used as a thickener and a natural stabiliser (E-410) is of great importance in different products (ice cream, sauces, creams, mayonnaise, etc.). The agroforestry utilisation of this species is another aspect being studied, emphasising the extensive sheltering of stock, providing fruit, shade and its association with some herbaceous cultivation (grass, cereals etc.); and land restoration of warmer zones to reduce erosion problems and desertification of the soil.

Table 1. Area of orchard trees, isolated trees, and approximate production of the carob in Australia.

StateArea (ha)Isolated
adult trees
Carob bean
production
 (number)(tonnes)
Western Australia11012,000300
South Australia5010,000250
New South Wales55,000125
Victoria53,00075
Total17030,000750

* Some 15,000 trees are female and therefore productive.

Recently some non-governmental organisations, such as the International Tree Crops Institute (ITCI), Men of the Trees, Land Management Society, etc. and government centres, such as the South Australian Department of Primary Industries in Loxton, and a private organisation of producers (Carob Growers Association in Western Australia) have shown an outstanding interest in encouraging the cultivation of the carob, its processing, and the consumption of carob pulp, for human nourishment as well as for stock fodder.

Production, marketing and industrialisation
The production of carob in Australia is estimated to be 750 tonnes annually and is located mainly in the states of Western Australia and South Australia. The greater part of the crop is destined for stock feed (sheep, cattle, goats, etc.), located in the same cultivated zones. Australia is an importer of the dried fruit, especially the toasted carob-bean flour (carob powder) and the locust bean gum. In the last few years an average of 100 tonnes of toasted carob-bean flour were imported, mainly from Spain and Italy, for an approximate value of AUD$150,000. Annual imports of locust bean gum vary around 800 - 1,000 tonnes, with a purchase price in 1993 of AUD$ 5.06/kg. This corresponds to a total value of some AUD$5 million (Esbenshade, 1994). Spain dominates this market, with more than 50% of the exports.

The distribution chain of carob products is relatively short and generally it directly links the importer, who uses it in the food industry (ice cream, chocolates, etc.) with the retailer. There are some exceptions in the use of distributors that act in the food chains of the different states, and of wholesalers specialised in supplying health food shops and local supermarkets. There do not exist industries of carob-bean traders. However it is anticipated that in the next few years, at least two will be established in the principal producing states. There exists, however, several food industries that use the toasted carob flour as a substitute for cocoa in chocolates and bakery products, and others that employ locust bean gum for the manufacture of ice cream, pet food and microwave fast foods.

Ecology
The zones in Australia where the carob is cultivated are characterised by a Mediterranean climate, with high temperatures in summer months, low annual rainfall (250 - 450 mm), mild winters and rare frosts. The lack of water, in critical periods of the productive vegetative cycle of the carob, and the frost risk, for example at Burra in South Australia, are perhaps the principal limiting factors in obtaining good crops in some potential cultivation zones. Table 2 shows the two climatological zones of the states of South Australia (Loxton) and Western Australia (Geraldton) where. there exist orchards compared with two in Spain (Tortosa, Catalonia), located in the northern hemisphere.

The temperatures of Tortosa compare well with those of the Australian zones producers, with a difference of 6 months because of the southern hemisphere location. The plantations located in the states of South Australia (Loxton, Burra, etc) and Western Australia (Geraldton, Perth, York, etc.) are characterised by a climate similar to the temperate Mediterranean and subtropical Mediterranean types respectively, according to the ecological classification of Papadakis.

The temperatures of Tortosa and Loxton are similar, however, the annual rainfall of Tortosa (576 mm) is double that of Loxton (275 mm) and evapotranspiration (ETP) is almost half. The climate of some of the cultivated areas of Western Australia (Geraldton, York, etc.) is warmer, with greater evaporation and somewhat less rain than that of Tortosa (Tarragona). In both Spain and Australia the carob orchards normally are therefore found in drylands, though some of them also exist in irrigated areas. In regions with very low rainfall, the carob subsists by using the water of the subsoil, thanks to its strong tap-root system.

Soils of the cultivation zones (South-West Australia) are, as a rule, low in fertility, most are of poor texture and can be cultivated only with difficulty. The carob orchards are found in better soils - clayey, brown or reddish - of neutral pH or alkaline and usually low in phosphorus.

Some non-governmental organisations show interest by encouraging the cultivation of the carob, its industrial trade, and the consumption of the carob fruit for human nourishment, as well as for that of stock.

Varieties
The carob trees that exist in Australia are produced largely from seed. Therefore, there exists a great heterogeneity. At the beginning of the 1980s, the ITCI imported 12 foreign varieties originating in Europe and California to introduce them to different states of the country (Esbenshade and Wilson, 1986). They originated from a varietal collection, now disappeared, that was located in Vista (California).

Also, at this time, some farmers began to select interesting local types for the good size of the fruit and high content in flesh and sugar. This means that there does not exist systematic studies on the behaviour of carob varieties in the different cultivation zones. There is, however, four recent cases concerning collections, mainly with foreign clonal plant material, that produce fruit with high flesh content. Three of them are found in the state of South Australia (Loxton, Burra and Gawler).

The most important is located in the Loxton Research Centre, where, in the ninth year, the cultivars 'Laguna', 'Santa Fe' and 'Clifford' (USA), Tylliria' (Cyprus), 'Sfax' (Tunisia) and 'Amele' (Italy) had all achieved good production levels. Some farmers of Mediterranean ancestry have introduced, in the course of the years, varieties of their respective original homes. Most of these have not been tested.

The varieties cultivated in Australia are characterised by having a high flesh content, the production being destined for animal food. Spain, in contrast, currently recommends varieties with a high content of seed. The gum is then extracted and is used as a food additive (Tous, 1994 ), to satisfy the demand of the European market for this product. Also they are using some male trees to pollinate the female varieties in the commercial orchards. Emphasis is placed on the following foreign and local varieties:

Local: In the state of South Australia emphasis is on the female cultivar 'Bath', 'Irlam', 'Maitland' and 'Paxton'. In Western Australia there are varieties produced called 'King's Park No.1', 'Princess', 'Marshall No.1 and 5', 'Collins', and 'Banks No.2, 3 and 4'. The cultivar 'Princess' is given significance since it has a high sugar content in its flesh (almost 60%). The clones of the series 'Banks', selected by the author in the area of Perth, are characterised by producing fruit with good yields of seeds.

Foreign: In new orchards they have begun to graft the female varieties 'Tylliria', originating in Cyprus, 'Amele' of Italy, 'Casuda' of Spain, 'Sfax' of Tunisia, and the hermaphrodites 'Santa Fe' and 'Clifford' of the USA.

In the last few years in New Zealand, where there exist some 20 ha of carobs, the farmers have emphasised the introduction of the Australian varieties 'KP-1' and 'Marshal No. 1'.

In summary it could be said that at this time there are several varieties for new orchards. There do not exist clear evaluation criteria in this regard, due to the fact that the trials are very recent and incomplete. Not all of the potential local plant material has been selected yet. Furthermore, there does not exist much experience in cultivation. Agronomic and commercial criteria (flesh and/or seed) are the most important in this regard, as well as selection of the clonal material. The zones where the carob is cultivated are characterised by their high temperatures in the summer months, low annual rainfall, and mild and infrequent winter frosts.

Characteristic of typical orchards
The carob orchards in Australia are recent, the oldest being dated at the beginning the 1980s. Currently these have begun to produce the first commercial crops. In this section will be described some characteristic of interest of these same orchards.

Size of plantations. Areas of the carob plantations tend to be small, between 1 and 5 ha, though there also exist two large plantations, each one of them having some 40 ha, located in the localities of Burra (South Australia) and York (Western Australia).

Propagation. The method mainly used in the orchards has been by direct seeding or by planting seedlings with subsequent grafting of the variety selected in the field at two to four years old. Currently some nurseries are experimenting with the technique of top grafting and also propagation by cuttings rooted under mist. This is quite recent in this country. Perhaps because of the shortage of commercial nurseries, and large distances, farmers set up their own nurseries to produce the necessary free graft wood to cover their needs.

Planting densities. The densities used vary between 100 - 200 trees / ha, with spacing of 10 x 10m, 9 x 9m, or 6 x 8m. On some developments the carob is also used as a species for hedges, in association with other cultivation.

Techniques of cultivation. The orchards, as a rule, receive little cultural care, due basically to the fact that it is considered a new crop in this country. They do, however, emphasise, among others the following:

The system of 'no tillage soil maintenance' is used, mainly to eliminate weeds and reduce competition, by application of herbicides under the crown of the tree, and leaving the natural green cover between the tree rows.

'Branch pruning' is quite light or absent with respect to the interior of the crown. The branches at the base of the trunk are pruned to leave the height of the cross of the tree at about 1 metre to help with future mechanical harvesting of the fruit with trunk vibrators.

Pests and diseases. The carob in Australia does not have excessive plant disease problems. One might emphasise, however, in young orchards, the damage done by birds that destroy the soft shoots of the young trees. Animals (rabbits, kangaroos, etc.) also gnaw the bark of the trunk and eat the leaves, mainly in the drought years when there is little food.

Final considerations
The cultivation of the carob tree in Australia is relatively new. In given areas of some States of this country, mainly in Western Australia, there is a considerable interest to encourage this cultivation. It is anticipated that increases in planted areas in the next years will occur for agroforestry uses and to satisfy the potential internal demand of carob-bean flesh, largely for animal nourishment.

The Australian consumer seems to know the beneficial characteristics for human health of this typically Mediterranean dried fruit.

It is accepted also, that in the last years there has been a growing trend in imports of toasted carob-bean flour, as well as in locust bean gum, for its use in the food industry. The Australian consumer seems to know the beneficial characteristics for human health of the carob flesh, and the natural thickener uses of the locust bean gum, of this typically Mediterranean dried fruit.

Current cultivation technology is little developed. The same is true for the study of the existing clonal plant material. This situation could be improved with the beginning of investigation activities and/or experiment (R & D) in this regard on the part of the competent Australian organisations.

Acknowledgments
These results are the fruit of a technical visit to Australia in the month of April 1994 accomplished by the author. My thanks for the financial support of the International Tree Crops Institute (ITCI), the University of Adelaide, and the Deputy of Tarragona. Also I desire to express my gratefulness to Dr. Henry Esbenshade (ITCI), Mr Farnell Hobman (Loxton Research Centre) and Mr Graham Brookman (University of Adelaide), for helping me gather information on the cultivation of the carob in Australia.

Bibliography
Eliass Castillo, F.; Ruis, L., 1977. Agroclimatologia de España. Cuadernos INIA, 7 Ed. Ministerio de Agricultura. Madrid, p. 350.

Esbenshade, H., Wilson, G. 1986. Growing carobs in Australia. Ed. Goddard and Dobson, Victoria, 136 p.

Esbenshade, H., 1994. Olives and Carobs for landcare and profit in southern Australia. Olives and Carobs National Symposium, University of Adelaide (South Australia), Roseworthy Campus: 5-17.

Hobman, F.R., 1994. The potential for an Australian olive industry. Olives and Carobs National Symposium, University of Adelaide (South Australia), Roseworthy Campus: 29-42.

Tous, J., 1994. Carobs: A worldwide perspective on the industry and management. Olives and Carobs National Symposium, University of Adelaide (South Australia), Roseworthy Campus: 46-52.

Translation by A. Murphy from the Spanish article of Dr Joan Tous Marti, "Situacion del algoarrobo en Australia" (Boletin Agropecuario de la Caixa, vol. 35, Jan-Mar 1995). Dr Tous is attached to an Arboricultural Research Centre in Tarragona, Spain.

Based on an article serialized in 'Algarrobo', newsletter of Carobs Australia, 1997-98.
WANATCA Yearbook 22.

JUAN TOUS
San Antonio 44-2, Vilaseca Tarragona, Spain

DATE: November 1997

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