|Amaranth to Zai Holes, Ideas for Growing Food under Difficult Conditions (ECHO, 1996, 397 p.)|
|4: Multipurpose trees|
All trees are multipurpose. They bring subsoil nutrients to the surface, provide shade, and slow erosion. Many trees provide fodder, living fenceposts, fruit and other edible parts, shade, insecticides, and wood; they all have some role in soil stabilization and offer quality- of-life benefits like beauty and a shelter for informal gatherings. Working with trees is an important investment which can be significant to the future of your community. Developing agroforestry systems, tree nurseries, and fruit and nut tree species is most appropriate for those with a long-term commitment in an area. Learning the valued qualities of the trees already present in and native to your area is a good starting point. Ask about the best local woods for fuel, construction, musical instruments, stakes, and other uses; ask children about the season and flavor of native fruits. Observe closely how various species are propagated, harvested, and protected. This chapter gives ideas and information on the many uses of trees in agricultural systems, various species, and working with trees.
ICRAF is the International Centre for Research in Agroforestry, headquartered at United Nations Avenue, P.O. Box 30677, Nairobi, KENYA. Their research is directed at mitigating tropical deforestation, land depletion, and rural poverty through improved agroforestry systems. ICRAF (1992 Annual Report) defines agroforestry as "land-use systems and practices where woody perennials are deliberately integrated with crops and/or animals on the same land management unit. The integration can be either in spatial mixture or in temporal sequence. There are normally both ecological and economic interactions" between the trees and other components of an agroforestry system. ICRAF focuses on sustainable technologies for small landholders in the humid to semi-arid zones of the tropics. They have a wide variety of excellent publications and are a good contact for questions related to the use of various tree species in agricultural systems.
"PRINCIPLES OF AGROFORESTRY" (10 pp.) by Dr. Frank Martin and Scott Sherman is a basic introduction for those with little or no prior experience in this field. They define agroforestry as "the integration of trees, plants, and animals in conservative, long-term, productive systems." Agroforestry is seen as an approach to agriculture, not a single finished technology. Benefits for the farmer include: food, feed, fuel, fiber, soil conser- vation and renewed soil fertility. Tables include: trees with edible products; principle agroforestry species; successful examples from various locations; successful examples of integrating trees and crops; and seed suppliers. The tables are followed by a section of definitions, a bibliography, and two pages of related resources and organizations. Available from ECHO for $3; free to development workers.
A TOOL KIT FOR FOLKS INVOLVED IN AGROFORESTRY. IIRR's Agroforestry Technology Information Kit is just the kind of practical resource we are always looking for. The kit is a collection of practical, well- illustrated summary sheets on various technologies related to agroforestry and sustainable agriculture in the tropics. It was originally designed for use by social forestry officers and technicians in the Philippines. Some of the common names of plants will not be familiar to most, but the information contained in the kit would be of interest to a wide range of development workers.
Topics are divided into the following basic categories (followed by a sampling of topics): Soil and Water Conservation Technologies and Agroforestry Systems (SALT-1, alley cropping, in-row tillage, A-frame use and construction, vegetative barriers, controlling cogon [grass], etc.); Annual Cropping System (cover crop selection, upland rice cultivation, root crops, cultural pest management, etc.); Seeds and Plant Propagation (seed collection, processing, testing, storage, and pre-germination treatments; tree nursery establishment and management; plant propagation, transplanting, etc.); Trees and Their Management (SALT-3, boundary plantings and shelter belts, pruning, fruit trees for harsh environments, growing bamboos, bank stabilization, species comparisons, etc.); Livestock Production (SALT-2, forced feeding, housing, plant-based medications, intensive feed gardens); and Home-Lot Technologies (medicinal plants, bio-intensive gardening with agroforestry, mini-ponds for dry areas, fertilizer from farm wastes, etc.). There is probably nothing in the kit that ECHO does not already have in our resource center. However, to have it all summarized in a highly pictorial manner is very helpful. Basically, it is a collection of simple, proven, basic, sustainable technologies with potential for further exploitation by resource- poor farmers. Kits are available in booklet form for US$27 from IIRR, 475 Riverside Drive, Room 1035, New York, NY 10115, USA; phone: 212/870-2992; fax 212/870-2981; e-mail email@example.com. Kits are also available (US$8/P200 plus postage, very reasonable in Asia) from the IIRR headquarters in the Philippines at IIRR Bookstore, Silang, Cavite 4118, PHILIPPINES; phone 63-969-9451; fax 63-969-9937.
AGROFORESTRY TODAY is published by ICRAF, a non-profit international research body governed by a board with equal representation from developed and developing countries. ICRAF's mandate is to "initiate, stimulate and support research leading to more sustainable and productive land use in developing countries through integration of trees in land-use systems." The articles were more practical and applied than their research orientation had led me to expect. Articles in the one issue included "Agroforestry: a very social science," "Readings in social agroforestry" [a bibliography], "The great eucalyptus debate," "The apple ring Acacia", and an article on beekeeping and forestry. I will quote from the latter.
" 'The secret of extending the period when flowers are available to bees,' says Dr. Michel Baumer [ICRAF staff], 'is paradoxical.' Best results are achieved by planting trees which are actually somewhat ill-suited to their environment. 'If you plant trees that are well-suited to an area, they'll flower when all the other trees flower,' he says. 'But those which are not at their ecological optimum, which are slightly marginal to local conditions, will often produce their flowers at a different moment than their neighbors. Some trees under these conditions even react by producing more flowers than normal.
" 'For example, Eucalyptus gomphocephala gives better results in some places in North Africa than on its native sandy plains of southwestern Australia. There are tens of thousands of flowers on an adult eucalyptus .... Even one tree represents a considerable source of nourishment for a bee colony.' ...A tree of great potential for dryland beekeepers is the apple ring acacia, Faidherbia albida, also called Acacia albida. For beekeepers in the Sahel-Sudan area it has the advantage of producing flowers at the end of the rains (most trees in this area flower before or during the rainy season) and it is the main source of nectar and pollen, if not the only one, during two or three critical months.'"
Subscriptions are US$40 for individuals. Those unable to pay may state their case for a free subscription. Order from ICRAF, United Nations Avenue, Gigiri, P.O. Box 30677, Nairobi, KENYA; phone (254 2) 521450; fax (254 2) 521001; e-mail ICRAF@CGNET.COM. It is also available in French and Chinese.
"ALTERNATIVES TO SLASH-AND-BURN" BULLETIN. ICRAF is coordinating a "Global Initiative for Alternatives to Slash-and-Burn Agriculture." Publication of this quarterly bulletin is part of that effort. It highlights ASB activities around the world, including research at three benchmark sites in Cameroon, Brazil and Indonesia and related training programs. Add your name to the mailing list by writing ASB Update; ICRAF; P.O. Box 30677; Nairobi, KENYA; fax (254 2) 521 318; e-mail D.BANDY@CGNET.COM.
AGROFORESTRY STUDY TOURS. (Abstracted from Agroforestry Today.) Technical and Study Tours, Ltd. organizes study tours in Kenya focusing on agroforestry, agriculture, forestry and the environment, as well as wildlife safaris. Participants can become acquainted with more than a dozen successful agroforestry projects, meet with ICRAF staff, make use of ICRAF facilities, and visit their field station at Machakos. Contact Technical and Study Tours, P.O. Box 50982, Nairobi, KENYA; phone (254-2) 791227/780461; fax (254-2) 780461.
RESTORATION FORESTRY: AN INTERNATIONAL GUIDE TO SUSTAINABLE FORESTRY PRACTICES edited by Michael Pilarski, 1994, 528 pp. It is difficult to put together a resource this comprehensive! This well-researched and -indexed reference manual distills 15 years of dedicated experience in this field. Over 50 authors contributed, and it serves as a sourcebook for information on over 2400 forestry books, articles, organizations, periodicals, and individuals. It is an excellent and international overview of sustainable forestry. Model forestry projects are described, university degrees in forestry are mentioned, and complete contact information is given for most entries. Available for US$26.95 plus postage ($4.05 in USA; $6.75 overseas surface; $21 overseas airmail) from Friends of the Trees, P.O. Box 4469, Bellingham, WA 98227, USA; tel/fax 509/485-2705.
A NETWORKING NEWSLETTER FOR AFRICA. Since 1990 the Methodist Church Division of Social Responsibility and the Methodist Relief and Development Fund have produced a networking newsletter called Africa Link. It is part of their Africa Water and Agroforestry Program, and it is published twice a year in English and French. Typical contents include brief news items provided by members telling what they are doing, conferences or workshops they have held or plan to hold, and references to resources available in Africa. Each recent issue has included a complete reprint of an article selected from another publication which the editor believes would be of interest to members. An item we gleaned from the last issue (how to keep rats from young oil palm trees) appears in Chapter 8. African development workers can write them at Methodist Relief and Development Fund; Division of Social Responsibility; 1 Central Buildings; Westminster, London SW1H 9NH, UK; phone 071 222 8010; fax 071 799 2153.
DIRECTORY OF INTERNATIONAL TRAINING AND EDUCATIONAL OPPORTUNITIES IN AGROFORESTRY. Several have asked us where you could go for a degree in agroforestry, a question that we have not found easy to answer. So we welcome publication of this 78-page book by the United States Department of Agriculture. "One of the most severe limitations to the successful adoption of agroforestry land-use systems has been the dearth of personnel with the knowledge and skills to integrate the various disciplines required in researching, planning and managing agroforestry interventions." The book covers universities and other institutions, degrees and short courses, in the USA and overseas. This 1993 book is free from Robin Maille, USDA Forest Service, International Forestry, Franklin Ct. Building #5500W, P.O. Box 96538, Washington, DC 20090-6538. ICRAF/Nairobi is now preparing and publishing this directory, and they are working on a 1995 edition, as new programs and courses are coming on line all the time. To order a copy or to let them know about a course your institution offers, write ICRAF at their address above.
SHADE FOR INCREASED SOIL FERTILITY UNDER TREES. A report by John Wilson in the January-March 1990 issue of Agroforestry Today suggests that shade may be one of the leading factors for increased soil fertility in agroforestry systems. We know that agroforestry systems can increase soil fertility, presumably by pulling nutrients from deeper in the soil or by nitrogen fixation from leguminous trees. There are frequent reports of improved grass growth under tree canopies, but the grasses grown under the canopies may be species which prefer shade over full sun. For example, an Australian study reported "a 250% higher yield of Panicum maximum under the canopy of a leguminous tree, Albizia lebbeck, than outside the canopy in full sun." Dr. Wilson's work found a 30% increase in growth of the grass Paspalum notatum under 50% shade of the non- leguminous Eucalyptus grandis and a 70% increase in total nitrogen in the grass compared with grass in full sun.
As evidence for his theory, Dr. Wilson cites an experiment he performed in an open pasture field of Panicum maximum where shade was the only factor. Areas were covered with shade cloth so that the sunlight was 50% of its normal intensity. The total herbage yield in shaded areas increased 43%, nitrogen in the leaves increased 43%, and the soil nitrogen increased 106%. He attributes this to lowered soil temperatures (maximum centigrade temperatures of 30-36 under shade verses 45-50 in full sun). The lower soil temperature promotes microbial activity and soil mineralization. "This influence is important in areas where the soil nitrogen level is a limitation to crop or pasture growth."
NEMATODES IN AGROFORESTRY. Nematodes are tiny "wire worms" that abound in the soil. The root- knot nematode, Meloidogyne incognita, is one of the most infamous, both for its devastating effect on crops and the ease with which its presence can be identified. It causes knots to form on the roots, in some cases making roots look something like a string of beads. Other kinds of nematodes also cause major crop losses, but require a nematologist to identify them.
The increasing use of agroforestry systems in which trees and shrubs are permanently grown in close association with annual crops raises an interesting question. How do these associations affect nematode damage, especially if the trees are themselves hosts for nematode survival and population build-up? This question is addressed in an article in Agroforestry Today by Mia D'Hondt-Defrancq (April-June 1993, pp. 5-9), from which the following is abstracted.
"Two types of interaction between trees and crops affect nematode populations. Direct interactions take place where the nematode population is directly influenced by the introduction of a species of plant new to the area or a new species of nematode." Indirect influences occur when the nematode population is altered by the local environment.
Direct Influences. Some species of trees and shrubs actually reduce the number of certain species of nematodes. This might be due to a chemical that is exuded which kills nematodes. In other cases the tree or shrub acts as a trap-host (it attracts nematodes but prevents their reproduction).
"In Nigeria, for example, the deliberate planting of Leucaena leucocephala in a fallow period dramatically reduced parasitic nematode populations in the soil. When the fallow was converted to leucaena alley-cropped with maize, the population of parasitic spiral and root lesion nematodes remained low. In West Africa, Sesbania rostrata acts as a trap host for the Hirshmaniella species of nematode that are prevalent in flooded areas where rice is grown."
"In cases where trees and shrubs are suitable hosts for harmful nematodes ... [the damage] may increase drastically. This is because the host will not only allow continuous build-up of the nematode population but will become a very efficient reservoir from which attacks can be made [on future crops]." For example, there were many more nematodes within 2.5 meters of a sesbania hedgerow in the Rwandan highlands than there were 5 meters from the row. In Malawi studies suggest that Acacia, Leucaena and Sesbania species can act as good hosts for root- knot nematodes. Presumably crops susceptible to this nematode will be more seriously attacked when grown in alleys with these trees. "Similar problems can be expected if Tamarindus indica or certain species of Acacia, Albizia and Casuarina are planted where the burrowing nematode is a threat to crops such as banana or vegetables."
Indirect Influences. Trees can reduce nematode problems by indirect interactions. For example, many crop plants have some natural resistance to nematode attack, but this is reduced by high air and soil temperatures (both of which are reduced by shade). Trees and shrubs can also reduce soil erosion and hence prevent the spread of nematodes that are attached to soil particles. To the extent that trees reduce growth of weeds that harbor nematodes, crop losses may be reduced. If benefits of the trees cause crops to be more vigorous, this in itself can reduce nematode injury. "There is also evidence that leachates from the litter of certain trees and shrubs [Ed: water that has soaked through the litter] have nematicidal properties, e.g. Azadirachta indica (neem), Ricinus communis (castor bean) and Leucaena leucocephala."
Indirect interactions can be negative. Plowing reduces nematode density. Reduced cultivation in an alley crop system can thus enhance nematode populations.
I have often wondered if knots caused by nematodes might not sometimes be confused with galls caused by nitrogen-fixing rhizobia. How can you tell them apart? "The nitrogen-fixing galls are readily identified because they are easily rubbed off from the roots and are often pink-red inside."
Many leguminous trees are also good hosts for nematodes. Nematode infection may reduce rhizobial colonization and, hence, nitrogen fixation.
"The following trees have been found to be resistant to the widespread Meloidogyne incognita (root-knot nematode): Acacia senegal, Acacia tumida, Anacardium occidentale, Azadirachta indica, Cassia obtusifolia, Cupressus sempervirens, Eucalyptus camaldulensis, Leucaena leucocephala (found resistant in most countries), Sesbania tetraptera and varieties of Sesbania macrocarpa." The author did not provide a list of trees that definitely are harmed by nematodes. He did mention that Sesbania sesban failed in east Africa due to nematodes. Sesbania grandiflora is badly damaged by them at ECHO.
ALLEY CROPPING TO SUSTAIN YIELDS. (By Daniel Sonke, ECHO staff.) Alley cropping is an agroforestry technique which has been widely promoted in agriculture development programs throughout the tropics. Many studies report increased harvests in alley crops versus control plots without trees. However, a report from ICRAF in Kenya suggests that alley cropping has been too widely promoted in areas for which it is not suited. The ICRAF report states that alley cropping should not be practiced in dry climates with acidic soils or in areas of low fertility. In some instances the competition between crop and tree roots negates the expected benefits of alley cropping. In others, yield increases were over-estimated because of procedural mistakes.
We contacted Dr. P.K. Nair at the University of Florida Department of Forestry for his perspective. Dr. Nair is a founding scientist of ICRAF, where he worked as a principal scientist for about 10 years. That interview is found later in this article, but first we will review the basics of alley cropping.
A BRIEF OVERVIEW OF ALLEY CROPPING. Alley cropping (AC) is the practice of growing food crops in alleys between hedgerows of trees or shrubs which are regularly "coppiced," or severely pruned. Sometimes the prunings of these trees are placed on the soil as a mulch around the food crops. As this mulch decomposes, its nutrients become available to the crops. Trees with roots which grow deeper than those of typical crops are used to bring nutrients up from the subsoil. Nitrogen-fixing trees are often used to maintain an input of nitrogen into the cropping system. In this way, soil fertility is maintained or improved despite the removal of nutrients in the crop harvest. Typically an AC system consists of trees planted 20-50 cm apart in straight rows which are 4 to 6 m apart (rows may follow the contour if on a slope). The specific width of alleys depends on many factors, including average rainfall and the crops grown.
A version of alley cropping called the SALT technique (Sloping Agricultural Land Technology) was designed to control erosion (see Chapter 5 on Farming Systems). In SALT, trees are planted only a few cm apart in double rows (rows 50 cm apart). The double rows, which follow the contour, reduce the chance of an opening through which water could flow. As water passes through the double hedgerow, it is slowed down and much of the suspended soil is dropped, eventually forming a terrace of sorts. Crops are grown in alleys between the double rows. The hedgerows in alley-cropped systems provide other benefits, including fodder and firewood, though some uses compete with their use as mulch and green manure. One report from an African region with limited trees states that farmers highly prized AC because they could grow more stakes for their yam gardens. ECHO used Moringa oleifera for its demonstration alley because leaves can be used for human food or animal feed.
Periodically the hedgerows must be pruned. For use as forage or mulch, a general guideline is to cut the trees by the time they reach 3 m in height or the stem diameter is more than 1 cm. The trees should be cut to 1 m or less. For some crops research has been done to determine whether timing of pruning is important for optimum nutrient availability. Delays in pruning may result in a "woody" mulch which does not decompose adequately. Obviously, AC is a labor-intensive venture not suited to farms with a labor shortage.
Some commonly recommended tree species are Leucaena spp., Calliandra calothyrsus, Gliricidia sepium, Senna siamea, Sesbania sesban, Grevillea robusta, and Acacia spp. Sometimes one may find that a native species is better adapted to local conditions and pests. Some general characteristics of a useful species are: -can be easily established -is fast-growing, producing much biomass -is deep-rooted, without many shallow, lateral roots -sends out new growth rapidly after repeated severe prunings -provides useful by-products (firewood, fodder, stakes) -has high protein (nitrogen) content in the foliage -has a compact canopy to prevent crop shading.
INTERVIEW WITH DR. NAIR.
Q. What do you think of the ICRAF report on AC?
A. The report has been blown out of proportion in some journals. The limitations cited are not new revelations. We have been saying from the beginning that AC is not suited to areas with limited water supply. In more humid zones it works beautifully well. In Kenya, for example, AC works very well in the humid regions, but very poorly in the drier regions. Unfortunately, too much eagerness by some people has caused it to be established without regard to its limitations.
Q. For what environments do you recommend AC?
A. Areas with poor soils and plenty of available moisture, where fertilizer is limited, and/or subsistence level agriculture is used. AC is effective on gentle slopes for preventing soil erosion; Haiti has working examples of this. I should caution that a plentiful low-cost labor supply is very necessary as well.
Q. What about the ICRAF recommendation against AC on acidic
A. I have seen successful examples on acidic soils in high rainfall areas (which is where acidic soils often occur) when appropriate tree species are used.
Q. What characteristics would you look for in a useful tree
A. High biomass production and nitrogen-fixation are desirable. The tree shape must not produce excessive shade to the crop. Generally species with small leaves or leaflets rather than broad leaves are used because of more rapid decomposition. Decomposition rate can be important; in some situations very rapid decomposition may result in the nutrients becoming unavailable to the crop. Where organic matter is lacking in the soil, slower decomposition may be desirable to improve soil. Leaves with high lignin or tannin may decompose too slowly. Each situation is different.
The trees chosen should not harbor pests of the crops, including birds for some crops and regions. Nor should the trees themselves be susceptible to pests. In Asia psyllids have destroyed many agroforestry projects using leucaena. Diversifying the species used in a region lowers the risk of losses to insects or diseases. Deep-rooting species are important; shallow-rooting species compete with the crop.
Q. Can the severe pruning of a tree alter its rooting pattern, causing a deep-rooting tree species to produce shallow roots which might compete with crops?
A. This is an area in which we are presently conducting research. I do not want to make a claim without concluding the research. [Ed: We hope to report on this when research is available.]
Q. Can you make a general recommendation on how wide the alleys
A. Alley width depends on the crop needs, available moisture, and the amount of mulch desired. Much research has been done using different alley widths. I encourage people to consult the research applicable to their situation. Keep in mind that more narrow alleys means more tree area and less crop area. The increased tree growth produces more mulch which should increase harvests. Finding the optimum balance between mulch production and crop area is the goal.
Q. Is AC self-sustaining in the long term?
A. As in any system, occasional inputs of nutrients result in longer-term sustainability. AC is designed for areas where fertilizers are limited, but over time even limited inputs will be beneficial. It is also important to realize that removing biomass from the system in the form of firewood or animal fodder makes it less sustainable over time. Although this produces benefits to the farmer, it requires more inputs to compensate. In Haiti the theft of firewood from hedgerows frustrates farmers' efforts to be sustainable. [End of interview.]
The ICRAF report criticized that some alley crop research stations have produced faulty crop yield data due to improper procedure. At two sites mulch was imported into the system to produce better mulch than the hedgerows actually produced. At another semi-arid site tree roots spread 15 m and actually grew into the plot which was supposed to be a no-tree control plot, which suffered reduced yields from root interference without the shade and mulch benefits of AC. One method suggested to correct this was to dig a trench around the AC system to prevent roots from influencing crops around it. Senna species are also being used in experiments, since their black roots can be easily distinguished from others. If you wish to do your own experiments on AC in your area, we encourage you to use similar methods to obtain good data. If you do have experience or data on AC successes or failures, ECHO would like to hear from you.
Mike Benge, USAID, Washington D.C., wrote in response to our article on alley cropping. "Many of the alley cropping systems ran into trouble with root competition when started with cuttings. Cuttings develop extensive lateral root systems, not true tap roots; however, they may develop pseudo tap roots. This causes severe competition for both moisture and nutrients. Gliricidia is a case in point. IITA started the alleys with Gliricidia cuttings, but after a while discontinued because of competition. They began to plant seedlings instead, which did not develop the extensive lateral roots, and found that competition was greatly reduced.
"From my observations in the field, once a tap root is cut, often it will not regenerate. Rather it develops a more extensive lateral root system and pseudo tap roots, which never reach the depth of a true tap root. This is extremely important in water-stressed areas. I suspect that aerial pruning in root trainers may have a similar effect; however, I have seen no research to prove or disprove this assumption."
FORESTRY CONSULTING ASSIGNMENTS. Are you looking for some new challenges when your present assignment ends? William Helin, with the U.S. Dept. of Agriculture Forest Service, wrote us about a listing of potential consultants maintained by the International Skills Roster; International Forestry; USDA Forest Service; P.O. Box 96538; Washington, DC 20090-6538; USA; or contact Ej Caplan by phone 202/273-4695. The database, which has 3000 experts in forestry, natural resource subjects, and disaster management, is used when the U.S. Forest Service, Peace Corps, USAID, or other development agencies request the help of consultants.
The skills most frequently requested relate to small-scale village forestry, farm forestry, or social forestry projects. There is increasing demand for expertise in resource management, environmental assessment, and land use planning. Consultants are requested in agroforestry, economics, environmental education, sociology, training, watershed management and wood energy. Other requests are for drylands forestry, nursery operations, plantation management, shelterbelts, soil conservation, and specialist skills related to these areas. Requests for long-term assignments of two years or more are almost always for persons with previous overseas experience, such as with the Peace Corps or PVOs. Most require either French or Spanish.
THE NITROGEN FIXING TREE ASSOCIATION (NFTA) became part of Winrock International's FACT Net (Forest, Farm, and Community Tree Network) in January 1996. The FACT net is a resource for information on both nitrogen-fixing and non-N-fixing multipurpose trees. They offer a technical advisory service for people with questions about the species, maintain worldwide seed source directories, and produce "FACT Sheets" (6/year) on various species and research reports, among other publications. (In the past we have mentioned NFTA's tree seedbank that was an outstanding resource to development organizations. That service is no longer available.)
For membership information, contact FACT Net, Winrock International, 38 Winrock Drive, Morrilton, AR 72110-9537, USA; phone 501/727-5435; fax 501/727-5417; e-mail firstname.lastname@example.org. The forestry staff provides a "global extension service" and can answer your questions by mail, phone, fax, and the Internet. This network is one of your best resources for information on many tree species. Some publications are available in Spanish, French, Indonesian, and Chinese; be sure to ask. The full set of about 100 FACT sheets on various species costs US$12 plus postage.
MULTIPURPOSE TREES AND SHRUBS: Sources of Seeds and Inoculants by Peter G. Von Carlowitz and published by ICRAF is helpful in locating seed sources of MPTs (multipurpose trees) and shrubs. (Another book, Cornucopia, is a great sourcebook for hard-to-find food plants. See the chapter on Seeds and Germplasm.)
Chapter 1 is a 40-page table listing: species name, seed suppliers and quantities available, number of seeds/kg, typical germination rates, and seed pretreatments. Chapter 2 is a country-by-country listing of information on the suppliers mentioned in Chapter 1: address, phone, telex, cable and fax numbers, type of institution (governmental, commercial, research, etc.), documentation available, currencies accepted, and forms of payment.
Chapter 3 is divided into thirds: an overview of nitrogen-fixing bacteria and other beneficial micro-organisms, a table of host species and related information, and a listing of inoculant suppliers. Chapters 1-3 end with an annotated bibliography of related readings. Chapter 4 has tables to help match the right tree or shrub with the right climate and use. The rest of the chapter is a comprehensive listing of species profiles from ICRAF's MPT database. Available (US$25 plus US$10 for surface mail; airmail rate supplied on request) from: Head of Information, ICRAF, P.O. Box 30677, Nairobi, KENYA.
HONEY-PRODUCING TREES SUITABLE FOR MULTIPLE USE. We phoned Dr. G. F. Townsend at the University of Guelph to answer a Peace Corps volunteer's question concerning the pros and cons of the African hive. Dr. Townsend is a leading authority on beekeeping in the tropics. He has been receiving ECHO Development Notes, so knows the kind of material we publish. When I asked if there were any things he would like to write up and share with our readers, he quickly volunteered the topic of this note. (I mention this as a hint for others, scientists or development workers. Have you learned something that can be shared with our readers?) The highlights of his notes follow. You can request the Technical Note from ECHO which contains the entire article. We do not like to feature plants unless we can provide seed, but we have been unsuccessful in obtaining seed of this entire list of trees. Please let us know if you could provide some to us.
What better way is there to solve the firewood problem than by planting fast growing trees that will also produce food and fodder? Some of the most suitable trees for this purpose are also valuable honey-producing trees that have nitrogen-fixing properties which will support grasses. Many of these trees are very adaptable to dryland conditions where the problem is most acute. A large proportion of the honey produced in tropical areas comes from trees, in contrast to the temperate regions where it is produced mostly from forage crops.
The growing of trees could make a community almost self-sufficient. Some of these trees, such as Prosopis species will produce food for humans and fodder for livestock within 3-5 years from seed, even in arid regions. They can be thinned for firewood and will support growth of dryland grasses. The beekeeping businesses they can support not only provide a valuable energy food but local and foreign currency from sale of beeswax. Work in Kenya has shown that beekeeping in many cases doubled or tripled the family income with no requirement for land and very little investment. With suitable infrastructure, no investment was needed at all.
The following trees are the most suitable for this purpose. [For additional information consult the book Firewood Crops by the National Academy of Sciences; unfortunately it is currently out of print. If you need more detailed information on these species, write the FACT Net at the address above.]
HONEY-PRODUCING TREES SUITABLE FOR MULTIPLE USES
A. Humid Areas
1. Calliandra calothyrsus
Firewood, animal fodder. Fast-growing.
2. Gliricidia sepium
Firewood, fencing, animal fodder.
3. Gmelina arborea
4. Guazuma ulmifolia
Firewood, timber, animal fodder, edible fruit.
5. Mangroves: Avicennia nitida
Resins, tannin, pulp.
6. Syzygium cumini
B. Tropical Highlands
1. Eucalyptus flobulus
Firewood, tools, poles, pulp.
2. Grevillea robusta
Firewood, cabinet wood, shade for coffee or tea.
3. Inga vera
Firewood, furniture, shade, food, seed pulp.
C. Arid Regions
1. Acacia senegal
Charcoal, poles, implements, gum arabic, fodder, food: dried seeds.
2. Acacia tortilis
Firewood, fence posts, animal fodder. Fast growing.
3. Albizia lebbek
Firewood, furniture, animal fodder. Tolerates salt.
4. Albizia citriodora
Firewood, poles, railroad ties, citronella.
5. Eucalyptus camaldulensis
Firewood, excellent charcoal, termite-resistant wood, pulp.
6. Eucalyptus citriodora
Firewood, posts, general construction, fodder, food: pods.
7. Pithecellobium dulce
Firewood, posts, general construction, fodder, food: pods.
8. Prosopis spp.
Firewood, fence posts, fodder: leaves & seeds, food: seeds, erosion control.
Fast growing, tolerates salt, arid conditions, up to 300 m.
Tolerates very arid regions up to 1500 m. May be weedy.
(The table "Other Important Tropical Honey-Producing Plants" is included in the Technical Note.)
TREES AND SHRUBS OF THE SAHEL: THEIR CHARACTERISTICS AND USES, by Hans-Jurgen von Maydell, 1990. Someone in our network in Mali brought this book to our attention. This beautiful 525-page book is still relatively compact (15x21 cm) for ease of carrying with you into the field.
The most striking feature is the large number of color photographs. Color photos illustrate the entire tree as well as such closeups as bark, foliage, flowers, fruits and/or seeds. For each tree, one page is devoted to photos and one to a written summary of key points (scientific name, family, description, distribution, site requirements, uses and references). Often, presumably for more important trees, additional pages of pictures and text are given. Appendices give vernacular names (in Bambara, Djerma, French, Gourmanche, Haussa, More, Peulh, Serer, Tamachek and Wolof); seed weights, pictures of seeds and fruits; and a list of botanical terms in English, German and French.
Order from Deutsche Gesellschaft fhnische Zusammenarbeit (GTZ); Dag-Hammarskjold-Weg 1-5; Postfach 5180; D-65726 Eschborn 1; GERMANY. If you write on official letterhead explaining how you would use it in your work with agricultural development in the Sahel, a free copy may be available. Those who do not qualify for a free copy can order from Margraf Verlag, P.O. Box 105, 97985 Weikersheim, GERMANY; fax 49-(0)7934- 8156; about US$49 plus postage.
SPECIES SELECTION FOR DIFFERENT CLIMATES AND USES. The Nitrogen Fixing Tree Association sent us this helpful list. Species followed by (*) have thorns.
Arid/Semi-arid Plants For Fuelwood/Charcoal.
Acacia acuminata, A. aneura, A. aulocacarpa, A. farnesiana (*), A. nilotica (*), Casuarina cunninghamiana, C. equisetifolia, Haematoxylon brasiletto (*), Parkinsonia aculeata (*), Prosopis pallida (*). Ibid. for Animal Fodder. Acacia albida, A. acuminata, A. aulocacarpa, A. nilotica (*), Cajanus cajan. Ibid. for Green Manure. Cajanus cajan.
Humid Lowland/Midland (0-1000 m) for
Acacia auriculiformis, A. mangium, Calliandra calothyrsus, Casuarina cunninghamiana, C. equisetifolia, Enterolobium cyclocarpum, Gliricidia sepium, Leucaena leucocephala, Mimosa scabrella, Samanea saman. Ibid. for Fodder. Acacia angustissima, Enterolobium cyclocarpum, Erythrina poeppigiana, Gliricidia sepium, Leucaena leucocephala, Sesbania grandiflora, S. sesban. Ibid. for Timber/Fuelwood. Acacia confusa, A. mangium, Albizia falcataria, Dalbergia retusa, Enterolobium cyclocarpum, Leucaena leucocephala, Samanea saman. Ibid. for Green Manure. Acacia angustissima, Albizia falcataria, Calliandra calothyrsus, Erythrina poeppigiana, Flemingia macrophylla, Gliricidia sepium, Leucaena leucocephala, Mimosa scabrella, Sesbania grandiflora, Sesbania sesban.
Tropical Midland/Highlands for Fuelwood/Charcoal.
Acacia mearnsii, Alnus acuminata, A. rubra, Leucaena diversifolia. Ibid. for Fodder. Acacia angustissima, Chamaecytisus palmensis, Leucaena diversifolia. Ibid. for Timber/Fuelwood. Artocarpus fraxinifolius, Alnus acuminata, A. rubra, Leucaena diversifolia. Ibid. for Green Manure. Acacia angustissima, Leucaena diversifolia.
The Kenya Forestry Seed Centre seed catalog has the most complete listing we have seen. Nine pages of the catalog give "Climate Zones and Species Suitability" based on humidity/rainfall, altitude, and mean annual temperature. These charts provide an important guide before you purchase seeds; for example, there are relatively few species suitable for over 2400 m altitude, but these lists give you a place to start. (We were not able to contact them at their Nairobi or Kikuyu addresses, so ECHO can send you the listing.)
THE NEW FORESTS PROJECT provides packets of tree seeds, technical information, and training materials free of charge to groups interested in starting reforestation projects with fast-growing, nitrogen-fixing trees. Available for distribution are seeds of Cajanus cajan (pigeon pea), Leucaena leucocephala, Gliricidia sepium, Robinia pseudoacacia (black locust) and Prosopis juliflora (mesquite). Write The New Forests Project, 731 8th St. SE, Washington, DC 20003, USA; phone 202/547-3800; fax 202/546-4784. Include an environmental description of your area, including elevation, rainfall, temperatures, soil type, and the purpose of the tree planting.
"FODDER TREE LEGUMES: Multipurpose Species for Agriculture" is a six-week course (offered in Nov/Dec in 1996) in Queensland, Australia. Participants learn about the range and characteristics of fodder tree species available and evaluate roles in animal production and soil protection. Cost in 1996 is A$12,000 (about US$8760) plus airfare to and from Brisbane. Write to Fodder Tree Legumes, Course Secretariat, Dept. of Agriculture, The University of Queensland, St. Lucia, Queensland 4072, AUSTRALIA; phone 61 7 365 2062; fax 61 7 365 1188.
ACACIA ANGUSTISSIMA AND CALLIANDRA CALOTHYRSUS. Lloyd Rowlands in Zaire wrote: "Another thing I am trying is Acacia angustissima. It out-performed 10 other species of trees from our NFTA trial. After 2 1/2 years it is 5 meters tall and about 6 cm thick! It is far better than leucaena in this area. I want to try incorporating it into an alley-cropping system. [Ed: In alley cropping, crops are planted in "alleys" between rows of trees that are planted a few inches apart and kept cut back to a few feet in height.] I have no other information on the species. Even NFTA, who sent the seed, has little information." (Neither does ECHO; please send us what you know.)
"The trial also included Acacia auriculaformis, A. melanoxylon, A. mearnsii, Calliandra calothyrsus, Casuarina cunninghamiana, Chamaecytisus palmensis, Leucaena diversifolia, Mimosa scabrella and Sesbania sesban. Due to drought, weeds and termites, only the first 5 species survived two years. After planting, the trees received no special treatment, as I was trying to do nothing that local farmers would not provide."
In a later letter, Lloyd wrote, "About 5 weeks ago a fire swept through the trees. Although all were killed above ground, A. angustissima are re-sprouting from the base and already average 55 cm high. Some are almost a meter tall. "This would seem to indicate that this species has good coppicing ability [i.e., ability to resprout from the base]. So they should be well suited to an alley cropping system.
"Calliandra is showing some signs of recovery with some shoots about 10 cm tall. Some nearby Leucaena leucocephala trees also burned. These are showing very poor signs of recovery. I cut down one tree. The wood is very hard, difficult to whittle with my rather sharp knife. I expect it will make good firewood or charcoal."
ECHO received a few seeds from NFTA and some from the International Livestock Research Center in Ethiopia. Seeds must be scarified by placing in hot water in the morning and left there while it cools and perhaps most of the day. Seeds are available only to our overseas network.
Robert Brook at the Lowlands Agricultural Experiment Station, Papua New Guinea, wrote: "In a past EDN, Lloyd Rowlands shared his experience with Acacia angustissima in Zaire. Here in Papua New Guinea we have been testing this tree alongside other leguminous species.
"At both sea level and at 1650 meters (4900 feet) it outperformed all other species, including Leucaena leucocephala K8 (and other varieties of leucaena). At sea level it grew at an average rate of 35 cm per month and after 8 months had a stem diameter of 5 cm. At 1650 meters it grew in 22 months to 2.6 meters tall with a stem diameter of 4.3 cm. Both are well watered sites. I have also planted at 2200 m, but have no results yet.
"The Royal Botanic Garden, Kew, England passed on the following information about this species. It comes from Texas, Mexico and Central America and is found from sea level to 2600 m. It prefers open sites, but is adapted to a wide range of habitats. It has a tendency to be something of a weed (an important point).
"Concerning the 'weediness' of A. angustissima, at our 1650 meter site naturally sown seeds do not germinate for a year or so, which indicates a dormant period. After this period seeds seem to germinate readily. It does not seem to set seed readily at sea level. For germination in the nursery, scarification (soaking in 90 degree C water for 30-60 seconds) is necessary. I have experienced no problems germinating it in a sawdust medium at sea level, but it does very poorly when sown directly in the field at low elevations; at higher altitudes it grows readily when field sown. Its fodder quality is reported from Australia to be poor, with low digestibility of nitrogen.
"Calliandra houstoniana is similar to the better known C. calothyrsus, but produces foliage even more profusely and naturally forms a more dense hedge. It looks like a good prospect for alley farming and erosion control barriers. C. calothyrsus is reported to have a high tannin content in the foliage, which makes it a problem for use as a fodder. I do not know if C. houstoniana has the same characteristics. It flowers profusely and butterflies love it, so it might be useful for bee keeping. Its glossy green foliage and relatively compact form (2.5-3 meters at sea level) make it a good ornamental.
"Our work with these and numbers of other species continues at a wide range of sites, so readers may like to write to find our latest results." His address is Lowlands Agricultural Experiment Station; P.O. Keravat; East New Britain Province; PAPUA NEW GUINEA.
GLIRICIDIA SEPIUM. Gliricidia is a fast-growing leguminous tree for frost-free tropical regions with 450- 3500mm rainfall. It is used for fodder, living fences, green manure, contour plantings, fuelwood, etc. It is fairly termite resistant. This species is native to Central American and Mexico. See Chapter 8 on Plant Protection for information on using this tree to kill rats.
Leucaena leucocephala is a fast-growing, leguminous tree
"I want to plant Leucaena, but which type should I choose?" Leucaena leucocephala is a fast-growing, leguminous tree that nearly all of you have heard about. It has been used for reforestation, for firewood, and as a forage crop that can equal alfalfa in nutritional value. Researchers have given it much attention in recent years. We have compiled the following recommendations from various sources in our files, especially from material provided by Dr. James Brewbaker, professor of horticulture and genetics at the University of Hawaii. There are three basic types of leucaena trees: Hawaiian, Salvador, and Peru. There are also crosses between these. You need to chose the type that best fills your needs. The Hawaiian type is short and bushy. Because its yield of wood and foliage is low compared to the other two types, this would probably be a poor choice. The Salvador type (Hawaiian giant) is tall and tree-like. The trees can grow 60 feet in height in 5 years. The best varieties of this type are K28 and K67. K67 is the best variety for projects that need high seed production. The Peru type is tall with extensive branching. The trees are good for forage; K6 is a good variety. An excellent forage-type leucaena is the Cunningham (K500) which was developed in Australia. It is a cross between the Salvador and Peru types.
Dr. Brewbaker has strongly recommended that we distribute more than one variety. He says, "...this is a self-pollinated, pure-line species, and it is a long-lived tree. We want to avoid spreading one variety over very large areas." (We presume this is because there is less danger of total loss from an insect or disease outbreak if several varieties have been planted.) His particular recommendation is that we distribute K28, K67 and K500. ECHO has these types among others and will be happy to send you several small packets for trial. If you want larger quantities or different varieties, write to us requesting a list of leucaena suppliers. We have addresses for suppliers in Asia, Australia, North and South America. We can also send a practical, two-page write-up by Dr. Brewbaker on how to germinate, transplant, collect and store seeds, etc.
Varieties K4 and K743 (hybrid) are low in mimosine, a chemical present in leucaena which can be toxic to animals when eaten in large quantities. Leucaena diversifolia is better for higher altitudes (500-2000m) than L. leucocephala; ECHO usually carries two varieties of this species.
See Chapter 8 on Plant Protection for information on the psyllid problems in Leucaena.
EYE-CATCHING LEUCAENA. Terry Waller wrote from Equatorial Guinea: "The velvet bean you sent before we were transferred to Bolivia was the most prolific and several church members were growing them in villages. The K8 variety of leucaena also grew great and we were able to introduce the concept of agroforestry. A recent letter from one of the farmers mentioned a surprising result: the aesthetic influence of agroforestry. He said that people from all over his neighborhood were coming by his garden (he lives in a very crowded slum area) and having pictures taken. Then they would get interested in the more practical aspects. Poor people like to feel good about their surroundings too."
THE MORINGA TREE, MORINGA OLEIFERA, IS CALLED MOTHER'S BEST FRIEND. That is one way they sometimes refer to this tree in the Philippines where the leaves of the malunggay, as they call it, are cooked and fed to babies. Other names for it include horseradish tree and drumstick tree (India) and benzolive (Haiti). Moringa is one of the most successful plants in ECHO's seedbank. Moringa tree leaves, pods, and roots are eaten; flowers are loved by bees; and seeds are powdered and used to purify water from murky rivers. I believe it is one of the most exciting and versatile plants that we have in our seedbank of tropical plants.
The leaflets can be stripped from the feathery, fern-like leaves and used in any spinach recipe. Small trees can be pulled up after a few months and the taproot ground, mixed with vinegar and salt and used in place of horseradish. Very young plants can be used as a tender vegetable. After about 8 months the tree begins to flower and continues year round. The flowers can be eaten or used to make a tea. They are also good for beekeepers. The young pods can be cooked and have a taste reminiscent of asparagus. The green peas and surrounding white material can be removed from larger pods and cooked in various ways. Seeds from mature pods (which can be 2 feet long) can be browned in a skillet, mashed and placed in boiling water, which causes an excellent cooking or lubricating oil to float to the surface. The oil reportedly does not become rancid and was once sold as "ben oil." The wood is very, very soft, though the tree is a good living fencepost. It makes acceptable firewood but poor charcoal.
It is an extremely fast-growing tree. Roy Danforth in Zaire wrote, "The trees grow more rapidly than papaya, with one three month old tree reaching 8 feet. I never knew there would be such a tree." The tree in our organic garden grew to about 15 feet in 9 months, and had been cut back twice to make it branch out more. It is well to prune trees frequently when they are young or they will become lanky and difficult to harvest. Where people begin breaking off tender tips to cook when trees are about 4 or 5 feet tall, the trees become bushier.
The folks to whom we have sent the tree in Africa have been pleased at its resistance to dry weather. Rob Van Os rated its growth, yield and potential as exceptional and added that it "can be planted after the other crops, even near the end of the rains." He has introduced it into several villages already. The first plants grew so well for Gary Shepherd in Nepal that he had us arrange for sending him 1,000 of the large seeds. He reports that at five months one was 12 feet tall and most were 6 feet.
There is more good news. The edible parts are exceptionally nutritious! Frank Martin says in Survival and Subsistence in the Tropics that "among the leafy vegetables, one stands out as particularly good, the horseradish tree. The leaves are outstanding as a source of vitamin A and, when raw, vitamin C. They are a good source of B vitamins and among the best plant sources of minerals. The calcium content is very high for a plant. Phosphorous is low, as it should be. The content of iron is very good (it is reportedly prescribed for anemia in the Philippines). They are an excellent source of protein and a very low source of fat and carbohydrates. Thus the leaves are one of the best plant foods that can be found." In his Edible Leaves of the Tropics he adds that the leaves are incomparable as a source of the sulfur-containing amino acids methionine and cystine, which are often in short supply.
It responds well to mulch, water and fertilizer. It is set back when our water table stays for long at an inch or two below the surface. We planted one right in the middle of our vegetable garden for its light shade. The branches are much too brittle to support someone climbing the tree. It is not harmed by frost, but can be killed to the ground by freezes. It quickly sends out new growth from the trunk when cut, or from the ground when frozen. Living fences can be continually cut back to a few feet.
CULTIVATION. I quote Alicia Ray, who wrote a booklet on the benzolive in Haiti some time ago. "It seems to thrive in impossible places-even near the sea, in bad soil and dry areas. Seeds sprout readily in one or two weeks. Alternatively one can plant a branch and within a week or two it will have established itself. It is often cut back year after year in fence rows and is not killed. Because of this, in order to keep an abundant supply of leaves, flowers and pods within easy reach, "topping out" is useful. At least once a year one can cut the tree off 3 or 4 feet above the ground. It will readily sprout again and all the valuable products will remain within safe, easy reach."
Scott Josiah writes that the Pan American Development Foundation in Haiti planted many kilometers of moringa as a living hedgerow on the contour of steep slopes, with mixed results. "In some cases, the growth has been excellent, nearly comparable to that of Leucaena leucocephala. However, M. oleifera has generally been a moderate performer, and seems rather sensitive to droughty sites and/or limited rainfall."
Beth Mayhood with Grace Mountain Mission wanted to establish a model vegetable garden on a small piece of land. "It was windswept and sunbaked with no natural barriers or trees in the area. Soils were poor and very alkaline. The salt content was also high. We started in January to prepare large quantities of compost. In April holes were dug in the poor soil and filled with compost. Benzolive trees planted in seedbeds germinated in 3-4 days. In 9 weeks they were transplanted in between the garden beds, around the edge of the 200 x 250 ft area and in a double row about 5 ft apart in the middle. The trees protected against the prevailing winds." I saw slides of this spot later. It was impressive. The light shade of the tree is a considerable help to most vegetables.
I cannot emphasize enough how important it is to use pruning of some sort. If left to itself the tree becomes quite tall and lanky. This method of cutting it back to 4 feet each year sounds good. One method I tried with some success was to cut each branch back a foot after it had grown 2 feet until it was a multibranched shrub. Alternatively, normal harvesting can have the same effect if begun while the tree is young. Beth Mayhood wrote, "We liked them so much we began picking the growing tips to boil as a spinach several times a week. This picking of the growing tips caused the tree to branch. Our constantly pruned trees became thick-limbed and many-branched."
I am told that when grown for its roots, the seeds are sometimes planted in a row like vegetables.
COOKING THE LEAVES. Alicia Ray writes, "Of all parts of the tree, it is the leaves that are most extensively used. The growing tips and young leaves are best. [Ed: However, we sometimes pull the leaflets off in our hands and cook them without regard to age.] Unlike other kinds of edible leaves, benzolive leaves do not become bitter as they grow older, only tougher. When you prepare the leaves, always remove them from the woody stems which do not soften. [Ed: We did not know this the first time we served them. It was like having wire in the dish.]
"The leaves can be used any way you would use spinach. One easy way to cook them is this: Steam 2 cups freshly picked leaves for just a few minutes in one cup water, seasoned with an onion, butter and salt. Vary or add other seasonings according to your taste. In India, the leaves are used in vegetable curries, for seasoning and in pickles. Let your imagination be your guide."
Ross Haliburton in Pakistan wrote, "We planted moringa seeds in April and, with hand watering, they have grown well. The tender leaves from six plants have been regularly used like spinach since July. A group of Afghan refugee men (chiefs and nurserymen caring for small nurseries in the refugee villages) visited us. When they saw the moringa trees they immediately asked for seed. We believe this tree has potential as a green vegetable in refugee villages, where there is a general lack of greens, especially through the summer."
Dr. Warwick Kerr wrote from Brazil that while he was the president of the State University of Maranhao, he organized a group of students and professors to carry out an extension project. They planted 25,000 moringa seedlings (all descendants from one small packet we sent him in an envelope a few years ago). "I like the moringa omelet that my wife prepares almost every morning. Collect a bowl of leaves, wash and fry for five minutes with sliced onions, garlic and salt. While this is cooling, minced tomato and onion are lightly fried then mixed with the fried moringa. Half a cup of this mix, two eggs and a spoon of any bullion soup mix are stirred and then cooked. It is delicious!" [He added that the chaya cuttings we sent made it fine and he has now distributed many plants in the community. "My wife is cooking it at least once a week and prepares it in many ways. This was the most sensational introduction: 8 small stalks in a regular airmail envelope!"]
Ronald Watts in Zimbabwe sent a copy of a letter to the editor that he wrote concerning moringa. It was published in "Productive Farming" magazine. "...I noticed several villages growing trees that I was unfamiliar with. They turned out to be Moringa oleifera. What was remarkable is that they were being grown for their leaves. One homestead had over 30 of these trees growing in a circle. In 36 years of wandering around Africa this was the first time I had seen trees grown in a traditional village purely for their leaves. The farmers said that the leaves were in high demand from their neighbors particularly in times of famine. Fresh leaves appear towards the end of the dry season when green food is in short supply. This tree would seem to have immense potential for improving human diets particularly in the hot and dry areas of Zambia and Zimbabwe. ...[Moringa] would seem to have great potential for feeding livestock. Several Zambian farmers who have tried leucaena for this purpose have been disappointed because it is extremely susceptible to termite damage. Moringa has the advantage that it is less susceptible and can be grown from cuttings. A 2-meter cutting means that from the day of planting the top of the tree should be out of reach of goats." Ronald says that though palatable to termites, moringa seems to be able to resist the challenge, particularly when grown from cuttings.
We have printed many success stories with the moringa tree. But cultures differ. Mr. C. N. Okonkwo in Nigeria ran into problems with acceptance. "All the seeds germinated and some are providing pods. Unfortunately I have not been able to convince any of the farmers to eat the leaves, except myself. The reasons are three: (a) the leaves have no eye appeal, (b) the leaves have a foul smell, (c) the growing tips have no commercial value. I am not disputing the claims regarding moringa. But in a community where so many broad-leaved vegetables thrive abundantly and some fetch good money, it is not hard to see why farmers look at this scanty small-leaved tree with some doubt."
COOKING THE PODS. Alicia Ray writes, "When young, horseradish tree pods are edible whole, with a delicate flavor like asparagus. They can be used from the time they emerge from the flower cluster until they become too woody to snap easily. The largest ones usable in this way will probably be 12 to 15 inches long and 1/4 inch in diameter. At this state they can be prepared in many ways. Here are three:
1. Cut the pods into one inch lengths. Add onion, butter and salt. Boil for ten minutes or until tender.
2. Steam the pods without seasonings, then marinade in a mixture of oil, vinegar, salt, pepper, garlic and parsley.
3. An acceptable "mock asparagus" soup can be made by boiling the cut pods until tender, seasoned with onion. Add milk, thicken and season to taste. Even if the pods pass the stage where they snap easily they can still be used. You can cut them into three inch lengths, boil until tender (about 15 minutes), and eat as you would artichokes. Or you can scrape the pods to remove the woody outer fibers before cooking."
COOKING THE PEAS. Alicia Ray writes that the seeds, or "peas," can "be used from the time they begin to form until they begin to turn yellow and their shells begin to harden. Only experience can tell you at what stage to harvest the pods for their peas.
"To open the pod, take it in both hands and twist. With your thumbnail slit open the pod along the line that appears. Remove the peas with their soft winged shells intact and as much soft white flesh as you can by scraping the inside of the pod with the side of a spoon. Place the peas and flesh in a strainer and wash well to remove the sticky, bitter film that coats them. (Or better still, blanch them for a few minutes, then pour off the water before boiling again in fresh water.) Now they are ready to use in any recipe you would use for green peas. They can be boiled as they are, seasoned with onion, butter and salt, much the same as the leaves and young pods. They can be cooked with rice as you would any bean.
"In India the peas are prepared using this recipe:
12-15 horseradish tree pods1 medium onion, diced
4 cups grated coconut
2 bouillon cubes
2 inches ginger root
4 T. oil or bacon grease
1 clove garlic
2 eggs, hard boiled
salt, pepper to taste
"Blanch both peas and pods' flesh, drain. Remove milk from 2 1/2 cups grated coconut by squeezing water through it two or three times. Crush ginger root and garlic, save half for later. Mix peas, flesh, coconut milk, ginger and garlic together with onion, bouillon cubes, oil, salt and pepper. Bring to a boil and cook until the peas are soft, about 20 minutes. Fry remaining coconut until brown. Fry remaining half of crushed ginger root and garlic in 2 T. oil. Dice eggs. Add coconut, ginger, garlic and eggs to first mixture, heat through. Serves 6.
THE DRY SEEDS. The dry seeds are apparently not used for human food, perhaps because the bitter coating has hardened. They are used for their oil, which is about 28% by weight. The oil can be removed by an oil press. I have heard reports that the residual cake is not safe to feed to animals, but I have not seen the results of any studies. Write to me if you have details. If an oil press is not available, seeds can be roasted or browned on a skillet, ground, then added to boiling water. The oil floats to the surface. Alicia Ray says that roasting is, however, not necessary.
Randy Creswell in Mali wrote, "The Khassonkes in Mali have been growing moringa trees for their leaves as far back as anyone's knowledge seems to go. Besides leaves, we have found good profit in a high quality edible oil readily pressable from the seeds. We are planting 1500 moringa seedlings."
THE FLOWERS. A visitor who had spent time in the Pacific area told me recently that the flowers are eaten there. Unfortunately, I do not recall details. Perhaps our readers can help. Alicia Ray says they are used in Haiti for a cold remedy. Water is boiled, then a cluster of flowers is placed to steep in it for about 5 minutes. Add a little sugar and drink as needed. It is very effective!
THE ROOTS. The tree is uprooted and the roots grated like horseradish. Alicia Ray says to one cup grated root add 1/2 cup white vinegar and 1/4 t. salt. "Chill for one hour. This sauce can be stored for a long time in the refrigerator." The following caution quotes from a recent review by Dr. Julia Morton in Economic Botany.
"The root, best known in India and the Far East, is extremely pungent. When the plant is only 60 cm tall, it can be pulled up, its root scraped, ground up and vinegar and salt added to make a popular condiment much like true horseradish. ...The root bark must be completely removed since it contains two alkaloids allied to ephedrine - benzylamine (moringine), which is not physiologically active, and the toxic moringinine which acts on the sympathetic nerve endings as well as on the cardiac and smooth muscles all over the body. Also present is the potent antibiotic and fungicide, pterygospermin. The alkaloid, spirachin (a nerve paralyzant) has been found in the roots.... Even when free of bark, the condiment, in excess, may be harmful." (The key words are "in excess"-the body can detoxify small amounts of a great many things.)
USE AS AN ANTIBIOTIC. A study at University of San Carlos in Guatemala is summarized. Herbal applications are commonly used to treat skin infections in developing countries, although few investigations are conducted to validate scientifically their popular use. A previous study had showed that moringa seeds are effective against skin infecting bacteria Staphylococcus aureus and Pseudomonas aeruginosa in vitro (i. e. in a test tube). This study showed that mice infected with S. aureus recovered as quickly with a specially prepared aqueous extract of moringa seed as with the antibiotic neomycin.
This study proves only the effectiveness of moringa as they prepared it. That preparation could be done in any country, but not with just household utensils. It was prepared by infusing 10 g powdered moringa seeds in 100 ml of 45 C water for 2 hours. The part that is a bit more complicated is reducing the 100 ml down to 10 ml by placing it in a rotavaporator. This is a very common piece of laboratory equipment which continually rotates a flask containing the liquid. An aspirator attached to a faucet produces a modest vacuum when the water is turned on. A rubber tube from the aspirator is connected to the rotavaporator, reducing the pressure and causing the water to evaporate rather quickly without boiling it. The ointment was prepared by placing 10% of the extract in vaseline. (We can send a copy of the article to medical personnel.)
Are you in a situation where there is a shortage of antibiotics? This ointment could be prepared for use in the local community wherever there is electricity and running water. Simpler methods, better suited to preparation as needed in the home, might also be effective. I hope someone will devise and test such preparations.
ECHO can provide trial-sized quantities of Moringa oleifera from the trees on our farm. For those seeking other potential sources we can recommend the following: Christas Cactus, 529 W. Pima, Coolidge, AZ 85228, USA; phone 602/723-4185. Greenleaf Seeds, P.O. Box 98, Conway, MA 01341, USA; phone 413/628-4750 (No telephone orders). Of the Jungle, P.O. Box 1801, Sebastapol, CA 95473, USA. Peace Seeds, 2385 S.E. Thompson Street, Corvallis, OR 97333, USA; phone 503/752-0421. Peter B. Dow & Co., P.O. Box 696, Gisborne 3800, NEW ZEALAND; fax (079) 78 844. Ellison Horticultural Ltd., P.O. Box 365, Nowra, N.S.W. 2541, AUSTRALIA; phone 6144-214255. Kumar International, Ajitmal 206121, Etawah, Uttar Pradesh, INDIA. Samuel Ratnam, Inland & Foreign Trading Co., Block 79A, Indus Road #04-418, SINGAPORE 169589; phone 2722711; fax 2716118.
Tom Post in Belize mentioned that his moringas are growing so well he now needs recipes. The Philippine book Learn to Eat Malunggay has 18 pages of recipes; write to ECHO for a photocopy.
Refer to Chapter 11 on Human Health for information on using moringa in water clarification.
If moringa does not already grow in your region, you may request a trial packet of the marble-sized seed. It grows wild in many places (such as Haiti and the Dominican Republic) where people do not know it is edible. The moringa is one of God's abundant resources for the struggle against world hunger.
MORINGA STENOPETALA. Moringa oleifera, native to India, is the number one seed in our seedbank, in terms of number of requests and positive reports. When we learned that a moringa native to Ethiopia had larger edible leaves, more drought resistance, and larger seeds (important for those using moringa to purify water), we were obviously interested. Dr. Samia Jahn shared some seed with us in the past, but our supply is very erratic; if you request seed (FOR OVERSEAS NETWORK ONLY), be aware that you may have to wait a while to receive the seed. If this is your first interest in moringa, please do initial trials with M. oleifera. If you have had success with M. oleifera, it may be time to try this "new" species.
Michael Madany wrote from Somalia of his comparison trial with seed received from elsewhere a few years ago. "In spite of the initial rapid growth of M. oleifera, in drier years the species has not done well without some watering. The M. stenopetala, by contrast, has the lushest green foliage and continued to grow during the exceptionally long dry season from last August until this April. We began cooking leaves and young shoots in April (taste of the two species very similar). We obviously aren't eating it fast enough, since two large limbs have fallen under their own weight." Freezes damaged our one M. stenopetala, forcing subsequent branching from low on the trunk. Consequently, I have not seen a "normal" mature tree. Dr. Jahn says that in the Sudan M. oleifera develops into a slender tree, M. stenopetala into a round shrub-like tree. Before the first freeze, however, a few important differences became clear. The trunk is considerably thicker at the base, the tree seems more vigorous, the leaves are larger, and if tasted raw the leaves are milder.
The more bushy M. stenopetala can be planted as a wind break. "Seedlings were planted in a windy corner at a spacing of 1 m. As soon as the upper branches of the tree grew broader, they were cut and the trees responded by more profuse growth of their lower branches, thus thickening the hedge. Vegetables cultivated behind it profited from this protection."
M. stenopetala has been grown as an ornamental in private gardens of Europeans in Kenya, reaching 10-12 meters and their trunk diameter is at least 2-3 times as thick as that of M. oleifera in Sudan. In Ethiopia it is cultivated as high as 1800 meters (5400 feet), where people use ash as the main fertilizer. By the end of a long dry season the trees may have lost their leaves.
We have been disappointed that ECHO's 8-year-old M. stenopetala tree has not yet flowered. We thought it was due to its having been badly damaged by two freezes. Dr. Jahn cites reports that M. stenopetala trees are not as quick to set flowers as M. oleifera. In Sudan the first flowers appeared after 2 1/2 years, compared to 11 months for M. oleifera. Charlie Forst in Haiti reported that his tree flowered in 15 months, grown from a cutting, which may make the difference. In the central plateau of Haiti, the low-branching, large-leaved M. stenopetala has far superior growth in the dry season. It is in full leaf after months without rain, while M. oleifera suffers after severe drought.
Michael Madany wrote again, this time from Kenya. "Since I am quoted in EDN with regard to our experience with Moringa stenopetala in southern Somalia, I'd like to send a few more comments. The last time I saw the trees we planted in February 1986 was January 1990. They had only flowered once (in 1987 or 1988; only a few flowers) and never set seed. Thus, whenever I wanted to plant more, I was obliged to use cuttings. As far as a source of green vegetable matter in the dry season, the tree surpasses its domestic relative Moringa oleifera in that climate (bimodal rainfall of 400-800 mm; 20-40 C). However, for the purpose of producing water-purifying seeds it seems to be not so successful, at least in the first 5 years. I am mystified as to the reasons for this. The provenance for our trees was over 500 km west at a considerably higher elevation." Michael mentions that during the civil war in Somalia the project buildings were destroyed and "all the trees in our garden were cut down."
Jay Ram wrote from the Pacific Neem Mission in Hawaii. "My Moringa stenopetala tree is now 10 feet tall and growing vigorously. I really share your enthusiasm for this wonderful tree. It is one of the best species we have come across. Fast growing with good form, and high palatability. In fact, I commonly will eat the boiled leaves by themselves, [something I do not do with Moringa oleifera which is common on the island]."
There is another interesting difference. The roots of M. oleifera are used as a condiment similar to horseradish. With M. stenopetala it is the bark that is so used.
Dr. Jahn reports on work in the Sudan which shows that optimum light for germination of all moringa species is half shade. When sown in the hotter weather of mid-April, germination percentages for M. stenopetala and M. oleifera were only 54 and 40 percent, compared to 92 and 94 percent in half shade. During the cool dry season there was little difference. Both moringa species can be started from cuttings. However, trees grown from cuttings are known to have much shorter roots. Where longer roots are an advantage for stabilization or access to water, seedlings are clearly preferable.
ECHO does not have a regular source for M. stenopetala. Watch future EDNs for availability, or write to be on our waiting list (send last date we should send seed).
THE NEEM TREE (AZADIRACHTA INDICA) FOR REFORESTATION AND AN EFFECTIVE INSECTICIDE. I first encountered the neem tree in Haiti, where hundreds have been planted along highways. I understand that it was chosen in part because it would grow very quickly and encourage the people that reforestation was possible. When I last visited Grace Mountain Mission in Port-au-Prince, there were 15-20 foot neem trees where there had been nothing a year before! Its seeds contain an especially effective natural insecticide. See Chapter 8 on Plant Protection for more on using neem as an insecticide.
The tree originated in India or Burma, where it is used widely for its insecticidal and medicinal properties. It is also grown in much of Africa, primarily for firewood. Seeds contain up to 40% oil which can be used for soap or lamp fuel. The residual neem cake is a good fertilizer with some nematicidal properties. (It is the neem oil that is primarily used as an insecticide; water extracts of powdered kernels also can be used in this way.) Neem is fast-growing and drought resistant, excellent for reforestation of semiarid lands. It is an evergreen (except in extreme drought) and valued for its shade-especially in cities-and windbreak protection. It grows best in deep, well-drained sandy areas, but thrives even on acid soils. It may fail in silty or clay soils and in waterlogged sites. To plant, pick fully ripe seeds directly from the tree and plant immediately. The trees may be direct sown or transplanted, and they benefit greatly from tillage, weeding, irrigation, and some fertilization in the first few months of growth (or after transplanting). Neem has been established in many countries throughout the tropics; there is a good chance you may find seed in country if you make inquiries.
A good source of additional information is the National Academy of Sciences publication Neem: A Tree for Solving Global Problems. It is available from: BOSTID Publications-HA 476, 2101 Constitution Avenue N. W., Washington, D.C. 20418, USA. ECHO now has it available for sale for $19.00 plus $2.00 postage in the USA. If you work with small farmers in the developing world, write ECHO before ordering about how this book would be useful in your work; you may qualify for a substantial discount.
Ordering neem seed can be difficult. The seeds may be viable for less than a month. You are strongly encouraged to find local sources of the seed. When ECHO receives an order, we hold the orders until either our tree produces (which it does not do every year) or we obtain a fresh shipment from overseas. For those visiting ECHO, we often have seedlings available in our nursery. We also refer you to some potential U.S. sources:
EXTRACT: AgriDyne Technologies, Inc., 417 Wakara Way, Salt Lake City, UT 84108, (801)583-3500; fax 583-2945. Ringer, Valley View Road, Eden Prairie, MN 55344. Jim Walter, W.R. Grace Washington Research Center, 7379 Route 32, Columbia, MD 20861, (410)531-4000.
SEED: Seeds are only available on a seasonable basis, as they must be planted within 3-4 weeks of harvest.
Agricultural Research Service (ARS), US Department of Agriculture (USDA), 13601 Old Cutler Road, Miami, FL 33158, (305)238-9321. The Kerr Center for Sustainable Agriculture, Vero Beach Research Station, 7055 Cherry Lane, Vero Beach, FL 32966, (407)562-3802. Robert Barnum, Possum Trot Nursery, 14955 S.W. 214th Street, Miami, FL 33187, (305)251-5040. FLAG Unit, International Livestock Centre for Africa(ILCA), P.O. Box 5689, Addis Ababa, Ethiopia. The Tree Seed Program, Ministry of Energy and Regional Development, P.O. Box 21522, Nairobi, Kenya.
SEEDLINGS: Saleem Ahmed, East-West Center, 1777 East-West Road, Honolulu, Hawaii 96848, USA; phone 808/944-7111. Robert Barnum, Possum Trot Nursery, 14955 S.W. 214th Street, Miami, FL 33187; phone 305/251-5040. John Conrick, Winter Park, FL; phone 407/384-7616. Chip Gardner, CA; phone 209/674-9543. Pacific Tree Farms, 4301 Lynnwood Drive, Chula Vista, CA 92010 ($36 per plant, no seeds). Marlin Huffman, Plantation Botanicals, Inc., PO Box 128, Felda, FL 33930; 813/675-2984, fax: 675-4591, (top quality West African germplasm from Larson, planted mid-1991). Sandy Mush Herb Nursery, Rt. 2, Surrett Cove Rd, Leicester, NC 28748; 704/683-2014, (root cuttings).
The Neem Association, 1511 Oneco Avenue, Winter Park, FL 32789, USA. (May be closed.) Axel Bosselmann, POB 1166, Charters Towers, 4820 Qld., AUSTRALIA (publishes Neem Notes).
OVERSEAS SEED SOURCES (for those working overseas only please):
Jean Hanson, ILCA, FLAG Unit, P. O. Box 5689, Addis Ababa, ETHIOPIA.
The Tree Seed Program, Ministry of Energy & Regional Development, P. O. Box 21552, Nairobi, KENYA.
Henry Doubleday Research Association, Ryton-on-Dunsmore, Coventry, CV8 3LG, UK; phone 0203-303517. H.E. Ostmark, Ph.D., Director of Research,
FHA (Fundacionduree Investigacigrla, Apartado Postal 2067, San Pedro Sula, HONDURAS; phone 504/68-2078, 68-2470; fax 504/68-2313 (willing to fill requests for Neem from Central America. Available September only).
Rene D. Haller, Baobab Farm Limited, P.O. Box 81995, Mombasa, KENYA; Telex 21265; phone 485729/754/501.
Roy B. McKenzie, McKenzie Agrisystems, Ltd., PO Box 95979, Mombasa, KENYA; phone 433460 Mombasa, 747131 Nairobi; fax 432309 Mombasa.
Tanzania, Forestry Research Institute, Silviculture Research Centre, P.O. Box 95, Lushoto, TANZANIA.
Forestry Research Institute of Malawi, P.O. Box 270, Zomba, MALAWI; phone 522866/522548.
Kenya Forestry Seed Centre, Kenya Forestry Research Institute, P.O. Box 20412, Nairobi, KENYA, phone: 0154-32541.
Regional Seed Centre, Forestry Commission, Forest Research Centre, P.O. Box H.G. 595 Highlands, Harare, ZIMBABWE; phone 47070/46878/9.
Nathanael Ariyo Olonire, P.O. Box 2674, Sokoto, NIGERIA, West Africa (bulk neem seed, leaves etc.).
Professor S.X. Charles, Director, "Thayagam", 172 K.P. Road, NAGERCOIL-629001, Kanyakumari District, Tamil Nadu, S. INDIA.
India Nursery & Seeds Sales Corporation, P.O. Box 4314, 36/962 DDA Flats, Kalkaji, New Delhi-19, INDIA (neem seed bulk).
Shivalik Seeds Corporation, 47 Panditwari, P.O. Prem Nagar, Dehra Dun -248 007 (UP), INDIA; phone 91 135683348; fax 91 135 29944.
Kimberly Seeds, 51 King Edward Rd, Osborne Park 6017, AUSTRALIA; phone (09) 4464377 (neem seed bulk).
Green Gold Intl., 14071/5, Prabhat Nagar, Dholewal, Ludhiana 141003, INDIA; phone 0091(161)535461; fax 009(161)28515, 34793 (neem seed or stem cuttings from superior seeds for rooting under mist).
CROSS-POLLINATE TO GET NEEM SEED. Norman Siegel in Mexico asked about a neem tree that did not bear seed. They ended up with only one tree from the seed packet we sent. This can easily happen because neem seeds are only viable for perhaps a month. "We have been reproducing it by cuttings but it has not yet seeded." The problem may be that neem must be cross-pollinated with an unrelated neem tree. We planted two neem trees at ECHO, about 200 meters apart. We waited in vain for fruit to set the first two years after they reached blooming age. The next year we had a small tree in a pot that was blooming, so positioned it on a small platform near one side of the larger tree. That year we had fruits in a circumference of a few feet around where that pot had sat. I have never read of this requirement, but in most real-life situations other trees would be nearby.
We planted a second tree beside our one tree. Last year it bloomed, and both trees produced fruit. We grafted this tree onto the more distant tree. The tiny grafts gave a few blossoms and I believe we got some fruit. Our Edible Landscape Nursery is preparing to sell neem trees with an unrelated graft so that home owners who only have room for one tree can get seed. A veneer graft takes well.
By the way, a 26 F freeze had this effect on our seven-foot neem tree: I had water spraying on the tree that night at about 4 feet. It was fine from there down, but after some weeks the leaves above 4 feet dropped. Eventually all parts that were not protected with water spray died.
NEEM IN AFRICA. Ralph Kusserow in Tanzania wrote, "After reading about the neem tree in EDN I really wanted to try it, but was afraid to order seed because it is viable for such a short time. Then I found that we have it here in Tanzania, though not in our area. In case you have anyone else in a Swahili-speaking area, it might help to know that it is called mwarobaini in Swahili. That means the "forty tree," so called because it supposedly makes medicines to treat 40 diseases. ...My main interest in neem is your report that the leaves can make a tea to deter termites. One of our friends has built a house every year for three years because of termite damage to the grass roof. I am anxious to see if neem leaf juice might be used in this situation."
PAULOWNIA, CHINA'S WONDER TREE. I asked Zhu Zhachua with the Chinese Academy of Forestry in Beijing, China for Paulownia seed after reading about it in IDRC Reports. [IDRC Reports is published by the Canadian aid agency, IDRC. Every issue is interesting. Contact IDRC, P.O. Box 8500, Ottawa, Ontario, CANADA K1G 3H9; internet email@example.com.] Two species of this broad leaf tree, Paulownia glabrata and P. elongata, are now widely planted in China, where it is adapted to most of their climatic zones. A 15 cm long root cutting can grow 18 feet (6 m) the first season. A 5-year-old tree can reach 17 m and have a 30 cm trunk diameter. Leaves make good animal fodder. It is planted for timber (though not of the highest quality) and firewood. It is intercropped with crops such as wheat, corn, millet and vegetables, to protect against wind, for shade, and as a green manure. Intercropped land in China has increased from 20,000 hectares in 1970 to 1.3 million today. For example, using 10 m rows and 5 m spacing in a wheat field, the yield of wheat was the same as in open-field cultivation. When the distance between the rows was increased to 20-40 m, the yield actually increased 7-10%. There are Paulownia plantations in the USA for export to Japan. ECHO does not have Paulownia seed; we refer you to Dr. Peter Beckjord at the National Paulownia Center, 10908 Dresden Dr., Beltsville, MD 20705, USA; phone 301/937-4635. You must send him US$1 to cover postage for basic instructions, a brochure, and an introductory packet of 500-1000 seeds. He also has much more information available if your trials go well.
SESBANIA ACULEATA FOR FIREWOOD THAT GROWS UNDER TOUGH CONDITIONS. Bob Burns in Bangladesh sent us a few seeds of this plant, also called Sesbania bispinosa, prickly sesban and dhaincha. According to the book Firewood Crops by the National Academy of Sciences, this is a quick-growing shrub that can produce a low-density firewood in only six months. In Vietnam it is grown in rice fields and its stems harvested for firewood before the rice crop is planted. It is a legume that nodulates vigorously. Its fibers are very similar to birch, one of the best trees for paper. Stems can be processed into a jute-like fiber, used for making fishing nets, sacks and sails. Other uses include for windbreaks, erosion control, cover crop and green manure. The leaves reportedly make good cattle fodder. It is well adapted to difficult soils. It will grow on saline and alkaline wastelands and wet, almost waterlogged soils, even in areas that often remain barren for want of suitable crops. No seed treatment is required. It grows so well that it is excellent at suppressing vigorous weeds such as Imperata cylindrica. (If you did not want the tree, it might itself become a serious weed pest.)
SESBANIA SESBAN RECOMMENDED FOR ALLEY FARMING AT HIGHER ELEVATIONS. (Common names: sesban, Egyptian rattle pod, suriminta, soriminta.) It is a great help to us when scientists in ECHO's network take the initiative to let us know about items of likely interest to our readers. A good example of this is a letter from Simon Chater at the International Livestock Centre for Africa (ILCA). He wrote, "A good alternative to leucaena for alley farming in highland areas (above 1800 meters) seems to be Sesbania sesban. We are growing this in hedgerows on broadbeds and ridges made with specially adapted ploughs in heavy clay soil. They are yielding 800 kg to 6 tonnes per hectare per year, depending on the cropping pattern. Under difficult highland conditions (frost, hail) in soils prone to erosion and waterlogging, this browse legume tree looks to be the most promising thing we have yet tried."
According to a paper from NFTA, Sesbanias: A Treasure of Diversity, sesban is "adapted to arid and semi-arid regions up to about 1200 m and to acid soils." I asked Nancy Glover at NFTA about this difference in recommended altitudes. Nancy said that there is a lot of confusion about limitations of altitude. Reported altitude requirements are so dependent on the latitude that they are often not at all comparable. It is possible that the two countries have quite different varieties.
The following information comes from the National Academy of Sciences book Firewood Crops, Vol. II. Sesban is a fast-growing, short-lived tree that regenerates rapidly after pruning. It is a copiously branched shrub growing no more than 6 meters. The wood yields an excellent gunpowder charcoal. Stems have been used for arrows, pipes, roofing for huts and, in fact, sesban is cultivated as a substitute for bamboo. Flowers are eaten as a vegetable, leaves eaten in Thailand, and the high protein seeds (33.7% protein) are a famine food in India (seeds must be soaked 3 days then cooked for half an hour to remove the toxic constituent caravanine). In India it is planted as a green manure in both dry and wet rice fields, plowed under before planting the rice. It is also used in India as a windbreak and shade for vegetables and as a support for grape, black pepper and cucurbits. It withstands acid soils, periodic flooding and waterlogging. It can endure 0.4-1% salt as a seedling and 0.9-1.4% near maturity. No seed treatment is required before planting. There are a lot of insect and fungus problems. The tasty leaves must be protected from cattle. (ILCA in Ethiopia originally supplied ECHO with some seed. They have since merged with ILRAD in Kenya to form ILRI, the International Livestock Research Institute. You may still be able to obtain seeds from ILRI at P.O. Box 5689, Addis Ababa, ETHIOPIA.)
SESBANIA GRANDIFLORA. Eliazar T. Rose of the New Hope Leprosy Trust, India, wrote, "I keep reading of people trying and promoting Moringa trees and from the seeds you sent us we have seen hundreds of trees extended. But wherever moringa grows here so does the Sesbania grandiflora. This is strong in the winds, grows just as fast, produces far more edible beans and flowers and is more attractive as fodder to goats and cows. If anything, after many years I would say first to sesbania and second to moringa."
[Editor: These are valuable comments. It shows how different two locations can be. When I planted the first moringa tree at ECHO I also planted a Sesbania grandiflora beside it. It indeed grew just as quickly. That fall a tiny "inch worm" totally defoliated the tree. When it happened the second year the tree died. We have tried many times since then. Each time we have had to spray the tree frequently to control the inch worms and even then eventually lost the tree to nematodes, which are as bad in our sandy soil as they ever get. It is one of the few important trees we just cannot seem to grow. We usually can send a small packet of seeds (which we obtain elsewhere) if you would like to see how it does in your area. If you need information on its use, make note of that with your request.]
TAGASASTE, CHAMAECYTISUS PALMENSIS, A TEMPERATE COUNTERPART OF LEUCAENA. The following is abstracted from the NFTA description. A small, shrubby tree from the extremely arid volcanic slopes of the Canary Islands holds promise for fodder, firewood and other uses in tropical highlands, Mediterranean climates and temperate regions. There are no thorns. Canary Island farmers have depended for centuries on tagasaste as fodder during the long, dry summers. New Zealand and Australian farmers are trying it today in cut-and-carry systems. Leaves contain 20-24% protein. All grazing animals and pigs and poultry readily consume the leaves. There are no reports of toxicity. Plant as a hedge for wind and sun protection. Coppicing ability is excellent (i.e. they come back when cut). It is the first tree to flower in the spring, so it is excellent for bees. Wood is popular for lathe work. It has potential for alley cropping. During the 2-3 year establishing phase, pruning back to ground level encourages multiple stems and self-protection when grazing commences. Sheep may eat the bark and kill trees. Tagasaste prefers sandy soils, but thrives on gravels, loams, limestone and laterites, as well as slag heaps and mining dumps. It does best with an annual rainfall of 350-1600 mm and soil pH of 5.0-7.0. Soils must be free draining to prevent root rot. Can survive winters of -9 degrees C. Can be inoculated with cowpea inoculant. Few insect problems. (ECHO has difficulties getting seed of tagasaste. If it grows in your area, we would like to hear from you and send you our seed import permit.)
FRUITS OF WARM CLIMATES by Julia Morton is an authoritative source for information on sub/tropical fruits from around the world. Possibly our most-used reference book at ECHO, this 505-page hardcover book has comprehensive information, excellent photographs, and practical growing hints for over 150 well- and lesser-known fruits and related species. It offers regional names, complete information on varieties, food value and toxicities, propagation, harvesting and storage, and medicinal uses, etc. of the various fruits. It is an indispensable resource for anyone who works extensively with tropical fruit production. Order from ECHO for US$75 plus postage ($5.50 within the US; $10 to Canada or Mexico) by credit card or check drawn on a US bank. Due to the weight and value of this book, we cannot ship overseas.
"TROPICAL FRUIT PRODUCTION AND RESEARCH" is a very popular graduate course that has been offered every other year at the University of Florida's Tropical Research and Education Center by Dr. Carl Campbell. When ECHO hired Scott Sherman as Assistant Director in 1988 the first thing he did was take that course. Although Carl is "retired" he still teams up with Dr. Jonathan Crane, the man who assumed his position, to offer the course in the summer (approximately mid-May to mid-June). This course is geared toward highly motivated students. You must register for credit through the university and pay tuition (which will be out-of-state for most of you). There are no special scholarships. A B.S. degree in a plant or agricultural science is a prerequisite (with some exceptions). Enrollment is limited. Lectures and field trips take place between 8 and 5 weekdays, so the course requires a full-time commitment. Contact Dr. Crane at TREC, 18905 S.W. 280 St., Homestead, FL 33031, USA; phone 305/246-6393; fax 305/246-7003. The course will be offered in 1996.
ECHO'S VIDEO SERIES ON TROPICAL FRUITS. Dr. Carl Campbell is well known to readers of EDN. His answers to your tropical fruit questions have appeared in many issues. Until his recent retirement, Carl was professor of tropical fruit at the University of Florida, responsible for teaching, research and extension. He is also known to many Floridians for his popularity on the speaking circuit at the many tropical fruit clubs in this State. His knowledge of and enthusiasm for the subject of tropical fruit is contagious.
Imagine standing under a mango tree with Carl while he shared the most interesting and helpful things he knew about mangoes. Then envision going to other trees and doing the same thing for 10, 20 or 30 minutes: avocado, canistel, loquat, macadamia etc. I had this privilege during four different seasons, videotaping his discussion. ECHO intern Mary Cockram, a communications and agriculture graduate of Cornell, then spent hours editing it down to approximately 8 hours of teaching. Now you too can meet Carl under some of his favorite trees!
The first tape in the series, called "Introduction to Tropical Fruit," was made last. We found that people coming to ECHO to study before heading overseas were so unfamiliar with tropical fruits that they did not even know it was a subject they should want to learn about. I must admit that 20 years ago, when reading the account of Adam and Eve in the Garden of Eden, I would envision them eating apples, pears, cherries and other temperate fruits. Most Americans would be hard pressed to even name a tropical fruit other than banana, pineapple, mango, and avocado. So we asked Carl to put together a 70-minute slide presentation. Fruits of the lowlands, middle elevations and then high elevations are discussed in order, each divided into major fruits, lesser known fruits with considerable potential, and locally important fruits. Every time I see it I am not only enthused again for the potential of tropical fruits in development projects, but am struck with awe at the richness of the world God has created for our joy and benefit.
The only other tape that was not made "standing under the trees" is the one on papaya and coconut. Carl's discussion of these two fruits is based around a series of slides.
The tape on grafting tropical fruit will be of special interest to many of you. Closeup photography and Carl's running comments show several of the most useful grafting techniques. After viewing this tape a few times, then getting some hands- on practice, you should have a powerful new tool for your ministry. You can use the tape in teaching if you provide the commentary in the local language.
TAPE # 1 - (73:03 minutes) Introduction to Tropical Fruit.
TAPE # 2 - (81:58 min). Part I. Grafting Tropical Fruit (60:08 min); Part II. Avocados (21:50 min).
TAPE # 3 - (85:13 min). Part I. Guava, pineapple and macadamia (34:30 min); Part II. Mamey sapote, sapodilla, eugenia family, jaboticaba, velvet apple, black sapote, white sapote, white mombin, strawberry tree (50:43 min).
TAPE # 4 - (79:02 min). Part I. Atemoya, passion fruit, inga, loquat and naranjilla (29:15 min); Part II. Akee, tamarind, jujube, carissa (21:16 min); Part III. Carambola, canistel, monstera, barbados cherry (28:31).
TAPE # 5 - (69:12 min). Part I. Mangoes (40:00 min); Part II. Papaya, coconut (29:12 min).
TAPE # 6 - (67:36 min). Part I. Banana and jackfruit (26:00 min); Part II. A conversation with Carl Campbell about tropical fruit and development (41:36 min).
ORDERING INFORMATION. Several have written asking us to remember that the world uses three video systems. We have done so, though the duplicating costs for other than NTSC tapes (NTSC is the system used in the USA) are much higher. Each NTSC tape sells for $29.95 plus shipping and handling; all six for $150. Prices in the other two systems, PAL and SECAM, are $40 per tape, $200 per set. FOR POSTAGE: contact ECHO. Payment must be in US dollars, either a check drawn on a US bank or your credit card (send authorization to use it and expiration date). Please add 6% sales tax for orders shipped to Florida addresses.
We are offering a subsidized price for only those readers who work directly through non- profit organizations to help peasant farmers or urban gardeners in the Third World. These qualify for a 50% discount on the price of tapes. Explain the nature of your work and name of the non-profit organization (unless it is on file with your EDN application). This discount applies also to PAL or SECAM, although in SECAM that price represents less than our costs of reproduction alone.
We are excited at the potential of video for taking the training to you. (Of course people studying at ECHO can study them here at no cost.) Other series are being planned. We welcome suggested topics. Maybe you could even offer some raw footage of your own on a special local technique that we could include in a future video. We especially want an evaluation of this series from those who use them.
TROPICAL AND SUBTROPICAL FRUIT TREES FOR ARID REGIONS. I spent some time in conversation with Dr. Carl Campbell recently about fruit trees for areas that are arid for much of the year. Dr. Campbell, researcher and state extensionist for tropical fruit in Florida, has been the source of other information in these pages. Sentences or phrases preceded by an asterisk mean that we need more information that some of you may be able to supply.
Balanites. This desert date is one of the toughest of trees in Ethiopia and Somalia. It is "survival fare," as the edible small fruit is bitter, but it is high in carbohydrate and is not toxic. *Who can get us some seed to share? Prickly pear cactus, Opuntia spp., can be quite productive. [Popenoe's Manual of Tropical and Subtropical Fruits (MTSF) says that the best varieties can produce on lean sandy or rocky soil, ill-suited for growing ordinary crops, with yields up to 18,000 pounds of fruit to the acre which would contain about 2500 pounds of sugar.] *Varieties have been selected but we have little information on this. There is some commercial production in California, Italy and North Africa. The fruits are quite tasty, about the size of a lemon. They can be started from seed, but more commonly from joints. Carl thinks quite highly of this fruit. MTSF says, "An important advantage is the regularity of the yearly crop. They begin to bear about 3 years after planting and continue for many years". If you cannot find plants locally you can write us for seed. I have not yet located a supply, so be patient. Indian jujube (Zizyphus jujuba) tolerates both fairly wet or fairly dry conditions and will grow in near desert conditions. It is a very vigorous and hearty tree that will take about anything except freezes. It is extremely productive and has few disease problems. Though it grows to a good size, it can be pruned into any shape and would be good for espalier. People feed leaves to goats during dry weather. Carl knows of no named varieties. Do not confuse this with the Chinese jujube which is hardy even into the Ohio valley in the USA but will not do well in warm climates like southern Florida. ECHO has seed each year around February. Imbe (Garcinia livingstonei) grows in some pretty arid places and is fairly productive, though it is not a desert tree. It has a bulbous base underground like many arid and fire-resistant trees. It is so closely related to the mangosteen that it can be used as mangosteen rootstock. Quoting from Sturrock's Fruits for Southern Florida, it is "quite hardy in southern Florida and grows equally well on the acid sandy soils and alkaline rock soils. [To be hardy here means it can stand high rain and humidity also.] (Several generations of) trees grown from seed were quite fruitful with little variation in fruits. There are male and female trees. The stiff, unsymmetrical growth and the grey-green stiff foliage give it an unusual and striking appearance. ...The small orange-colored fruits have a thick tough skin and a very large seed. The small amount of juicy acidulous pulp has a pleasant flavor. It is, however, more a curiosity than an economic fruit."
APPLES FOR THE HIGHLAND TROPICS. We became acquainted with Jim Abbott in 1982 when we were looking for someone willing to give attention to small overseas orders. Some of you will remember the "bench grafted" apple trees that he offered some years ago. These apple roots with scions grafted to them were so small that up to 30 could be shipped in a package the size of a shoe box. There were a few successes, but most shipments had died in transit.
I called Jim for an update. He has had better luck with bench grafted trees that were ordered in sufficient quantity to ship by air freight (faster than regular airmail). However, several of them still have died within a few months.
Now he prefers to dig up established but quite young trees, much younger than would be dug for domestic shipment. Typically he chooses plants 12-18 inches tall that were budded in May or July and dug in the winter. They are still small enough that a person could fit 100 trees into a suitcase.
Advance planning is essential, even with small orders. Jim likes to begin correspondence early in the year, but can only ship when the trees are dormant (mid-December through March). If you travel to the States, it would be ideal to talk with him by phone. Whenever possible it is best to transport the trees in a suitcase when returning home or when someone is visiting. Otherwise there may need to be an exchange of letters to determine just how the trees are to be shipped and how many dollars to send him in advance to cover shipping-which can be more than the price of the trees. Jim figures that the maximum safe time for trees to be in the mail is about two weeks. The trees themselves are US$2.50. (They would be less if you are ordering several hundred, but unless apples are already proven in your area I would hesitate to start with that many.)
Jim can provide a phytosanitary certificate if requested. You will need to check with your government to obtain necessary permits for importing trees. A very small hand-carried or mailed package might be allowed into some countries, but the risk of a large, expensive shipment dying in customs is too great not to investigate beforehand.
Recently Jim has sent fairly large orders to Ethiopia, and 28,000 trees to Honduras where a Japanese project has built a cooler to keep trees dormant until planting season. In Honduras (I believe at about 7,000 feet) the Excelsior plum and hood pear are also doing well. Chet Thomas wrote that the trees in Project Global Village's planting high in the mountains in Honduras did not need to be defoliated to blossom. They seemed to bloom frequently, even while apples were ripening on the tree. I heard the same thing from a site in Rwanda. Jim reported that blueberries are apparently doing well at one site in Honduras.
So what should you do? (1) I hate to ever say "never," but I would not bother with subtropical "temperate" fruits at elevations less than 3,000 feet (1,000 m). The cutoff elevation will be higher near the equator than at higher latitudes. Islands may have more moderate climates than sites well inland on continents. If I was at 6,000 feet I would begin to think of subtropical "temperate" fruits very seriously. (2) Write to Jim Abbott early enough to allow a few exchanges of correspondence. He will need to have payment for trees and shipping in advance. The address is Monticello Garden Nursery, 1200 Mahan Dr., Monticello, FL 32344, USA; phone 904/997-5482 or - 7202; fax 904/997-6759. (3) If you want them to come airfreight, how is word to be gotten to you quickly that they have been sent? It is much easier if you or a friend can hand-carry the trees. (4) Start small.
CASHEW AS A CASH CROP: IS IT AS GOOD AS IT APPEARS? You would be surprised how often we receive a question similar to this. It does indeed do very well on poor soil. However, Dr. Campbell has mentioned to me that it is seldom a successful development project. One serious problem is the terribly toxic fumes that are produced during processing. They can be safely processed on a large scale, but it is not simple to do. The Natural Resources Institute (Publications Distribution Office, NRI, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK) has some intermediate technology designs for processing cashews. My guess looking at the picture is that it would cost several thousand dollars.
I was replying to a question on cashews from Tom Taylor in Guyana when Dr. Frank Martin came by to begin work on a new teaching video for us on tropical root crops. I asked his opinion. Dr. Martin said that while cashew is often touted for areas where soils are poor, the tree has serious fruit setting problems. If there is excess moisture during flowering the fruit will not form. He gave this example. "A project I was consulting with in northern Haiti asked me to look at cashews. I questioned many farmers very carefully. It turns out that even though the climate is dry, there is enough condensation of water at night to impede fruit development." That does not mean it is never a good choice. "I have never seen it grow as well as it does in central Panama." Dr. Martin said that if you have not already had a successful experience with cashews (including good fruit set) in the particular area being considered, be careful.
He also pointed out that cashew trees are associated with poverty worldwide. There is so much labor involved that there is little income produced per person. So it has little promise unless there is cheap labor. "It is a poor person's crop and a crop for poor soils." If you know of a cashew project that would lead you to a different opinion, we would like to hear about it.
FLORIDA CITRUS PUBLICATIONS. Ed Noyes in Zaire wrote us about problems he was having with citrus, wondering if extension bulletins in Florida covered the topic. This led us to the Fruit Crops Extension office. (They used to publish a range of booklets on various topics, but that service is no longer available.) The information is now available for sale in book form; some titles are: Nutrition of FL Citrus, FL Dooryard Citrus, Rootstocks for FL Citrus, Citrus Disease and Insect Flashcards; FL Citrus Varieties, and Citrus Spray Guide. Each costs about $10 plus postage. Order from Florida Cooperative Extension; 2109 Fifield Hall; Gainesville, FL 32611, USA; phone 800/226-1764; fax 904/392-2628. [If you write to ECHO for information on a particular fruit, we may send you the 2-page University of Florida's Fruit Crops Fact Sheet on that plant.]
SOME NOTES ON GUAVAS from Wilson Popenoe's (out of print) classic book Manual of Tropical and Subtropical Fruits: "The guava is used primarily for jelly-making and other cooking purposes." "It is one of the least exacting of all tropical fruits in cultural requirements." "The guava succeeds on nearly every type of soil." "Plants should be set 10-15 feet apart." "It is the custom to propagate by seed, but choice varieties must be perpetuated vegetatively." "Both shield budding and patch budding are successful." "A simple method of propagation is to cut the soil 2-3 feet from the tree, severing the roots. Sprouts will soon make their appearance. When they are of suitable size they may be transplanted, giving a tree exactly like the parent tree." "The guava is subject to numerous insect and fungus enemies." "Unlike the preceding species, the strawberry guava is subtropical and can be grown wherever citrus succeeds."
THE JABOTICABA TREE, MYRCIARIA CAULIFLORA. A lot of local interest and publicity came our way with the opening of ECHO's "Edible Landscape Nursery." Our goal is to raise a portion of the expense of running this ministry by selling edible plants for both the yards and gardens of people in our local community. At the same time we are having a lot of fun acquainting our neighbors with some of the wonderful plants with which God has blessed our world.
A personal favorite is the jaboticaba tree. If I could rename it, I would call it "the grape tree." Early each spring the tree is loaded with purple fruits the size of large grapes. Fruits contain one seed which is larger than a grape seed but small enough that there is a lot of flesh to enjoy. The flavor and texture remind me somewhat of a muscadine grape. Uses are also similar to muscadine grapes. They can be eaten fresh, but the peel is tough enough that people often spit it out. They can be processed in ways similar to grapes, such as in jelly or wine. The visual appeal of the tree is striking. The trunk and larger branches, which are attractive in their own right, are suddenly covered with fluffy blossoms (in contrast to most fruit trees which set fruit on smaller branches). Soon the purple fruits almost hide the larger limbs.
There are drawbacks. The major limitation is that it is so slow to produce. Although Julia Morton's Fruits of Warm Climates mentions side veneer grafting, inarching and air layering, the conventional wisdom around here is that one might just as well start from a seedling. Seedlings are slow to begin bearing, typically about 9 years. Trees are very slow growing, reaching a maximum height of perhaps 30-40 feet. A second limitation is that they are not for the hot lowlands. They like a mountainous or subtropical area. At ECHO they only blossom during the coolest few months of the year. In some ideal (cooler) locations they produce several times a year. The tree is not harmed by frosts, nor by a freeze if it is light enough that it would not kill citrus.
If the weather cooperates, ECHO can share seeds each March. We will combine requests and fill at harvest time. Be sure to plant the seeds immediately, as they do not have a long life.
ARE MACADAMIA NUTS A GOOD CROP FOR BELIZE? Several have expressed an interest in macadamia nuts as a cash crop in one country or another, so our answer to this question may be of interest to many. Carl Campbell says, "Poor yield is a very common problem where people have planted in the Americas. In Hawaii they figure their break even point at about 100 pounds of nuts per mature tree. By comparison, in Florida we get 15-20 pounds. Macadamia trees seem to do best in the areas where coffee does best. Processing is a problem too. People have put in little plantings, only to find that they cannot get the nuts processed. Some have even shipped from Central America to Hawaii for processing. Many of those who have been in it the longest seem discouraged." Carl adds that Macadamia tetrafolia, the rough spiny leafed and rough shelled macadamia, is the preferred rootstock. M. integrefolia is the other macadamia.
COMMENTS ON WORMS AND POLYEMBRYONY IN MANGOES. William Boykin in Zambia wrote, "We had 40 trees of peach mangoes. They are a lovely orange color, have very little fiber and are delicious. For four years we had only a small crop and nearly all that did mature were full of worms. On the other hand, the common local mangoes hardly ever have worms-but they are very stringy and fibrous. As a result we had most of the peach mangoes cut down and planted the common variety. Is there anything we can do to control the worms in the few remaining peach mangoes?"
I phoned Dr. Carl Campbell. As usual, I learned more than just what I phoned to ask. Carl said the pest is most likely the larvae of the fruit fly, most species of which like mangoes. There is very little that can be done. It is considered impractical to spray an entire area to get rid of the fruit fly. However, in Central America some folks get a crude molasses from the sugar mill at very low cost and mix malathion with it. Carl does not know the proportions or dilution. A swath is then sprayed onto leaves as a person with a backpack sprayer walks down the row of trees. Because it is a bait, it is not necessary to cover all the leaves or even every tree. Flies are attracted to the bait and are killed by the insecticide. He has seen it work fairly well with the Mexican fruit fly in Honduras. To make sure your species of fruit fly is attracted to the bait, try placing molasses on a few leaves and see if it attracts flies. I asked at what stage this should be done. Carl replied that control would be important about 3-4 weeks before the fruit is mature. Carl referred me to Dr. Jorge Pena, a specialist in insect control with tropical fruit, to answer my question of, "Why is it not used in Florida if it works so easily?" Dr. Pena said it is used by some. The problem is that it is not specific and kills a lot of beneficial insects as well. [For this reason you should definitely use it only during that key time when the fruit is susceptible to infestation.] People also make traps out of vinegar, hydrolyzed protein or anything that will ferment, plus insecticide. This method is used mostly in greenhouse and research plots.
Is there a general rule that fibrous mangoes are less susceptible to insect damage? Not necessarily, but there are great varietal differences in insect susceptibility between fruits of many species, including mangoes. I always urge our readers to do some of their own experimenting. Plant a lot of mango seeds here and there and see what kind of fruit each yields. Perhaps you will come up with a superior mango that is even more resistant to the fruit fly! Carl is all for that, but said to watch out for polyembryonic mangoes. If you are still interested after that big word, read on.
Chances are extremely high that the local fibrous mango is polyembryonic. This means that each seed contains not only the embryo that resulted from cross-fertilization (called a gametic embryo), but also several (nucellar) embryos that developed from the parent tree's own tissue, the nucellus. Several trees may emerge from the single seed, but one of the stronger nucellar ones are more likely to survive. This can be a benefit if you like the parent tree and want to start identical trees from seed. But if you want to start trees hoping that some will be better than the parent you are out of luck. You can tell if you have the polyembryonic type by removing the husk from the seed. You will find a lot of cotyledons curled around each other. If it is monoembryonic, you will find two big cotyledons and a single embryo. Trees coming from monoembryonic seed will have a combination of genes from two parents, resulting in many different combinations of traits.
In summary, if you want to try to develop a better mango, get seed from as many sources as possible, and concentrate on monoembryonic seeds. (Citrus presents a similar situation. It would be a shame to plant 100 citrus trees hoping for a few superior ones only to find that all were polyembryonic and "came true" from seed.)
MANGO TREES THAT DO NOT PRODUCE. Jack Mahaney wrote us after visiting Gary Dawson in Venezuela. "While they have many large, mature mango trees, no fruit is borne. There are heavy crops at other stations within a hundred miles or less. What is needed in order to produce fruit?"
I called our standby for tropical fruit questions, Dr. Carl Campbell, who was familiar with the problem. The most common cause is a location where the trees bloom during periods of high humidity and temperature. This leads to anthracnose infection of the flowers and no fruit set. It can be controlled by spraying with fungicides, such as those containing copper, carbamate (e.g. Maneb), or benylate. It is so humid in southern Florida that Florida growers are wiped out most years unless they spray. There are varieties from Southeast Asia that will do better under such conditions. He mentioned varieties Saigon, Florigon, Pico and Carabao.
It is very difficult to get tropical fruit trees shipped overseas. If you know someone who has the tree, can you have seed sent? The good news is that all of these varieties are polyembryonic and consequently most trees will be just like their parents. The bad news is that mango seeds are viable for only a couple weeks after removed from the seed and dried. I asked whether you could extend the life of the seed by wrapping it in wet paper towels. Carl explained that mold is a terrible problem with seeds stored this way. The best approach is to surface sterilize the seed by dipping it in 10% chlorox, then pack it in barely moist (no free moisture should be visible) activated charcoal and ship in a plastic bag. (Might regular charcoal substitute for activated charcoal?)
There are locations where the trees do not even bloom. (Carl said you need to be alert because sometimes people have insisted their trees do not bloom, but more careful observers contradict them.) Fungicides will be no help there. For example, he has seen large areas in the Philippines where mangoes do not bloom. This appears to be due to the uniformity of high rainfall and temperature which does not permit the trees to have their normal dormancy. In 1972 scientists in the Philippines found that if they spray the leaves with as little as 10 g/liter of potassium nitrate, the buds will start elongating within 2-3 weeks and will bloom within a month. Spraying is done only once, but the trees are drenched completely. They time the spray to have bloom and fruit growth during the least stressful season possible. Apparently it is effective only when the tree has attained a "ripeness to flower." Signs of this stage include: leaves become dull green or greenish brown and brittle when crushed with the hand and the tree has an appearance of suspended growth. Another use of this technique is to induce earlier flowering to beat the market and get higher prices for the mangoes. The fruiting season can be advanced several months in the Philippines.
INTRODUCING NATIVE FRUITS IN ZAIRE. Roy Danforth and Paul Noren, Zaire. "It was slow going at the beginning of our program as people used to refuse to plant fruit trees for reasons such as, 'I'll die before the tree starts fruiting' or 'if a man eats fruit, he'll get a hernia and have to be operated on' or 'fruit gives me diarrhea.' But now jakfruit, canistel, rollinia, black sapote, yellow passion fruit, abiu and inga are big favorites with the local people.
"We now have several hundred species of fruits, nuts and other useful trees/vines and have planted them out in various locations ranging from a single tree in someone's yard to several acres in an orchard. Some species have little potential to help the people here as they take too long to come into production or the fruit is not of good quality.
"However, we have hit upon several really good winners for this area. The top vote getter with the local people is the canistel (Pouteria campechiana-see drawing), simply because it is good food. Its taste is similar to the sweet potato that is widely grown and eaten here [Ed: except that canistel does not need to be cooked.] Rollinia (an Annona) is a close second as it is a large fruit with a lot of edible flesh.
"Jackfruit (Artocarpus heterophyllus) is becoming more and more popular. Though not everyone appreciates it, those that do cannot get enough of it. More jackfruit trees have been planted than any other tree and many come into production in less than two years! Because they are seedlings, there is enough variation in fruit taste, consistency, latex content, etc. to find one that will please most everyone. ...The abiu is coming on strong as a popular fruit because the variety we are using has a short 2-year bearing age and produces large quantities of delicious fruit.
"A difficult problem here is thievery. These fruits are so popular that most of the fruit gets stolen off the trees before they are ripe. We get reports from everywhere that when villagers plant trees in their yards, the trees are dug up in the night and taken to who-knows-where.
"Other fruits that people continue to buy from the nursery include those that existed in the area before we started the agroforestry program. These include ambarella (Spondias cytherea), breadfruit, coconut, citrus, avocado and mango. Of the last three it is the grafted trees that are selling. Of the native Zairian fruit trees, only one has been developed extensively and that is the safu or Dacryodes edulis. There are quite a few cultivars of this species that are much larger and less sour than the wild ones and they come nearly true to seed." You can order seeds from them on an exchange basis or pay equivalent to US$1 for each tree type requested.
Roy Danforth, Paul Noren, and other missionaries with the Evangelical Covenant Church have, since 1978, worked with Zairian leaders in promoting programs such as agroforestry, animal husbandry, fish farming, appropriate technology, and rural development. If you want to visit them, fly Europe down to Bangui on a commercial airbus. Then take a small Caesna plane into NW Zaire and to the station near the town of Businga. One aspect of their work involves establishing "tree gardens" around villagers' homes to supply food, fiber, shelter, fuelwood, and other benefits of trees. They have a collection of trees that amounts to over 500 different species (mostly fruit) that they have received from sources all over the world, including ECHO. They feel that exchanging seeds and information has been the key element in the success of their agroforestry program and hope that more people get involved in networking. They published a small book, The Native Fruits of Zaire (US$25/copy), a free annual newsletter, and an agroforestry seed list ($2). Roy and Paul can be contacted at B.P. 1377, Bangui, CENTRAL AFRICAN REPUBLIC. (In the US, the book is available from Roy's father, Mr. S.C. Danforth, 6934 Lake Tree Ln., Citrus Heights, CA 95621; phone 916/729-6934.)
LIMIT FERTILIZER AFTER TRANSPLANTING TREES AND SHRUBS. [The following is adapted from the May 1993 issue of The Avant Gardener.] This has long been an accepted but unproven rule. Now a study by Dr. Warren at the North Carolina State University "has shown that root growth decreases as the amount of nitrogen fertilizer is increased. Nitrogen apparently does not enhance regeneration of roots pruned during digging.
"Many studies have demonstrated that after root loss, growth is redistributed in favor of making new roots. Above-ground growth slows as nutrients are transferred to the roots. So it is a mistake to apply fertilizer in an attempt to stimulate top growth, since the plant's 'instinct' is to regenerate a full root system. NCSU experiments showed that replacing damaged roots is slowed at a rate directly correlated to the amount of nitrogen fertilizer used. This may negatively impact transplant survival and prolong the establishment period. Little or no nitrogen should be applied in the first year after transplanting."
ECHO asked Dr. Warren to clarify some points. Does this apply only when the plant has been dug up and root damage has occurred, or also when a plant is carefully transplanted from a pot into the soil? "I have no direct data, but I believe it applies to all transplanted material since establishment is still dependent upon generating new roots into surrounding soil." Do you mean to add no fertilizer or just no nitrogen fertilizer? "The data is only applicable to nitrogen fertilizer. I would make sure there are adequate levels of P and K. Recent information suggests that these two do not interfere with root growth."
WATERING CUPS USED IN PLANTING TREES. Joel Matthews in Niger wrote, "In experimenting with direct seeding and transplanting seedlings, I have found that a trench with 'watering cups' greatly increased survivability of new seedlings in hot, dry sun scorched areas." In an area where Joel wanted to make a living fence, he dug a narrow trench about 8 inches (20 cm) deep. At spots where a tree was to be planted, he loosened the soil perhaps another 8 inches deep and made a slight depression for hand watering if needed. He calls these "watering cups."
"When preparing my living fence, I only did a portion as a trench; the others were in a slight depression. I direct seeded Ziziphus mauritiaca and Z. spina christi in mid May. After a 3 week moist period we had almost a full month without rain. The result-80% of the seedlings in the trench survived with periodic watering, whereas only 40% of the seedlings with watering cup only but no trench survived. My trial with no watering cups and no trench saw only about a 20% survival rate." Benefits cited include: lower soil temperature, greater moisture retention, wind protection, protection from animals, overhead shading possible (e.g. by placing corn stalks over the trench), water catchment, and improved microclimate. [Might birds be less likely to dig up seeds or pull up young seedlings?]
SUCCESSFUL METHOD OF TAKING FRUIT TREES FROM THE STATES TO ZAIRE. See above about Roy Danforth's large collection of tropical fruit trees. He collected many potted trees while in the States one winter. "In all I bare-rooted and bagged 315 trees, threw them into trunks and carried them for 4 1/2 days. I'm pleased to report that not one of them died in transport."
Here is Roy's procedure. (1) Shake the tree to remove most of the dirt from the roots. (2) Dip the roots in a bucket of clean water to rinse off the remaining dirt. (3) Spray the roots with a solution of 50% hydrogen peroxide and water, which releases oxygen for the plant to use in transit. (4) Shake off excess water, then slip a baggie [plastic sandwich bag] around the roots only and tie it tightly around the trunk. (5) Severely prune back [those trees which are too large for your suitcase], though do not remove leaves from what is left. Spray the leaves with an antitranspirant. [Roy used Poly-Trap, but there are many on the market. They form a polymeric film around the leaves and reduce the loss of water by transpiration. They are used commercially to treat seedlings before setting them in the field to reduce shock.] (6) Use no medium, such as sphagnum moss, for the roots because it is unnecessary and causes a lot of fuss with the plant inspectors. (7) Do not place bags on the tops, as this will increase the possibility of rot. (8) Lay the trees in the trunk, making certain they will remain stationary by careful positioning and use of padding. "I was worried about the temperature during our overnight in Paris in February, but it apparently had no effect." Roy is generous in sharing seeds and cuttings. Write him at B.P. 1377, Bangui, CENTRAL AFRICAN REPUBLIC.
MUD DIP FOR ROOTS WHEN TRANSPLANTING. From Eddie Visser in Guatemala: "While transplanting citrus and leucaena seedlings into the ground, the soil would sometimes crumble off, leaving the roots of the transplant exposed. When this happened we dipped the roots into a mud solution, so that the mud adhered to the roots. Almost all the transplants we did this to are still living. The ones we did not do this to died."
Timothy Volk with the Mennonite Central Committee in Nigeria wrote, "I noted Eddie Visser's comment on coating roots of seedlings with a mud solution. I recently was on a study tour in Togo and saw villagers doing the same thing. However, rather than using mud alone, they also mix in some cow manure and sand. We were able to see that the seedlings (leucaena mostly) did not dry out during the day and that earlier planted seedlings were doing very well despite a poor rainy season. In addition the manure provides a small amount of nutrients to promote early root growth."
TREE SPACING NUMBERS. How many trees would you need per hectare for a particular spacing between trees? The following comes from a booklet published in Colombia, Ccrecen los oles.
Distance Between Trees (in meters)
Trees per Hectare
2.0 x 2.0
2.5 x 2.5
3.0 x 3.0
4.0 x 4.0
GROW SMALL FRUIT TREES IN CIRCLES. (Excerpted from an article on permaculture in India in the International Agricultural Development, April 1992.) "A novel idea has been to grow some fruit trees, like bananas and coconuts, in circles about 3 meters in diameter. Inside the circle a thick layer of humus builds up. Circle planting makes it easier to water the trees. When trees are planted in a line they have to be watered separately, but in a circle watering occurs once from the center. There is also less shading of adjacent crops."
DANGER SIGNAL OF HEAVY FLOWERING. Peter Storey wrote from England: "In EDN you mentioned the 'hopeful' sign that many neem trees are going through a period of heavy flowering. This is not a hopeful sign. Unusually heavy flowering in trees can be a sign that the tree is having one last fling. It will use up its carbohydrate reserves and may die the next season. One of the signs of citrus decline is heavy flowering which is followed by death of the tree in one or two years.
"When plants (trees in particular) have a higher proportion of carbohydrates than nitrogen, their regulatory mechanism senses that they have plenty of reserves to produce fruit and so produce many flowers. In the opposite case, when nitrogen is higher than normal, the plant produces more leaves so as to make more carbohydrates.
"When roots are damaged by disease or pruning, the plant is less able to take up nitrogen and the ratio of carbohydrates to nitrogen increases. This is a signal to the plant that things are not so good and that it is likely to die. To ensure that it reproduces itself, it sends out a lot of flowers."
This reminds me of the technique of girdling used by some homeowners to bring fruit trees into earlier bearing. A complete circle is cut around the trunk wide enough to shock the tree but narrow enough that it eventually fills in and does not kill it.
"THE LIVING FENCE, ITS ROLE ON THE SMALL FARM," (6 pp.) by Dr. Frank Martin is a brief overview listing advantages and disadvantages of living fences. Five exceptionally useful living fence trees are briefly discussed. Finally, a 3-page table lists 66 species that have been used in living fences, their climatic adaptation, method of propagation, size, whether pruning is necessary, and other uses. Available from ECHO.
HEDGES FOR RESOURCE-POOR LAND USERS IN DEVELOPING COUNTRIES
hedges for resource-poor land users
When we offered our small Technical Note on living fences (above), I asked whether anyone knew of a well-illustrated and carefully written book on the subject of living fences. JHenninger in Paraguay told us about this book. He wrote, "Its 256 pages give orientation about techniques for establishing and management of hedgerows, uses and functions, social and economic issues and a list of species applicable. It has about 57 tables and 92 figures. I love this book because it is by far the most complete one I know."
Now that I have the book, I can understand his enthusiasm. The book is exceptionally thorough, perhaps to a fault. (My personal preference is for a "get to the point" briefer style of writing.) I have selected a few highlights to give you a flavor of the book, and because the information itself is worthy of a note in EDN.
"Lac production on hedges can be an incentive for soil conservation." Shellac is made from the resinous secretion by the lac insects. Several host hedge species are listed, including acacias and pigeon pea Cajanus cajan. "In Thailand lac lice raised on pigeon peas planted on contour bunds for erosion control has been promoted by one project. Loss of cropping area to the hedge row can be more than compensated by selling of stick lac and pigeon peas."
For many farmers the only option is a stockproof hedge without barbed wire. Such a hedge should be low- growing, sturdy, multi-stemmed from the base (or low branching), dense branching with rigid or entangling branches and a spreading crown, small, sparsely distributed leaves that cast little shade, have spines, prickles or thorns, be resistant to fire, trampling and browsing; require little upkeep; be capable of regeneration if damaged. Not many plants meet these characteristics. So often a mixture of plants are used to fill in the gaps and strengthen the barrier. The following categories can be distinguished: framework plants, fillers, and entanglers. Four pages with 15 tables list trees and shrubs (names only) with high potential for: food, forage, fuelwood, timber, soil conservation, ornamentals, fillers, irritants, entanglers, fence reinforcers, garden hedge, windbreak hedge, general security hedge, live fence post, tropical highlands, humid tropics, arid & semi-arid tropics.
The weakness of the book, for development workers, is that you can read a great deal and still not have much of an idea as to what to do locally. I found the four brief case studies especially relevant, and wish there had been four hundred. Two case studies are summarized next.
Villagers in Huancal, Peru (3600 meters, temperate cold, 600 mm rainfall) developed this system after natural vegetation disappeared. Small fields are surrounded by a living fence of Cassia. Annual crops are grown followed by a fallow period in which animals graze in the fields. Just before planting the trees are coppiced, leaves used for mulch and wood dried for firewood. The Cassia has been growing 4 years and the cycle starts again. A study showed that Cassia (planted 1.5 m apart in the fence row) makes an average family self-sufficient in their annual fuel requirement.
In arid watersheds, many flood plain farming communities have disappeared or shrunk because the land bases have been destroyed by flood. In contrast farmers in the upper Rio San Miguel have maintained a fairly stable agroecosystem. Use of living fences is a key reason.
Living fences are planted along the margins of the riverbank. Farming takes place on the floodplain. Flood water carries a heavy load of top soil from overgrazed rangeland upstream. As the flood begins to overflow into the space between the fencerows and the edge of the cultivated area, the force of the water is broken by the trees and by brush that is deliberately thrown in around their bases. (The brush also helps keeps cattle out.) The sediment load of the less rapidly moving water settles out behind the trees, fertilizing the fields. The fences also retard erosion and cutting of new channels. Eventually enough alluvium is accumulated behind the fencerows that cultivation can be extended right up to the row of trees [elevation is increased].
To make hedgerows, cuttings are taken from Populus fremontii (a cottonwood tree) and Salix gooddingii (a willow). Brush from various local species is woven between these vertical posts. Cuttings (3-4 m) are trimmed from all branches and leaves and planted in trenches (1.5x0.5x0.5 m) at a planting distance of 0.5-0.75 m. One cottonwood is planted between a dozen willows. Mature trees in older fencerows are pruned so that the trunk is about 2 meters.
The book was published by the GTZ, which will often send a book at no charge to a non-profit development group working in the developing world. You might write on official letterhead to see if you qualify. The address is GTZ; Postfach 5180; D-65726 Eschborn; GERMANY; fax 06196-797352. Those who do not qualify for a free copy can order for about US$26 plus postage from Margraf Verlag, P.O. Box 105, 97985 Weikersheim, GERMANY; fax 49-(0)7934-8156.
THE ITTO TROPICAL FOREST UPDATE is published quarterly in English, French, and Spanish by the International Tropical Timber Organization as a forum for information exchange on aspects of sustainable tropical forestry. This resource can keep you up-to-date on courses and current literature, make contacts working in your area, and give information on organizations and topics on forest management. The March 1996 issue featured fire in tropical forests around the world, production and trade of tropical logs, a country profile of Bolivia, details of upcoming seminars, and several pages of input from readers. This newsletter is free from the Editor, ITTO Tropical Forest Update, ITTO Secretariat, International Organizations Center-5th Floor, Pacifico-Yokohama, 1-1- 1, Minato-Mirai, Nishi-ku, Yokohama 220, JAPAN; phone 81-45-223 1110; fax 81-45-223-1111; e-mail firstname.lastname@example.org.